United States
Environmental Protection
Agency
Municipal Environmental 'Research  EPA-600/2-78-208
Laboratory          December 1978
Cincinnati OH 45268
Research and Development
Demonstration  of
Erosion and Sediment
Control Technology

Lake Tahoe  Region of
California

-------
                RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology.  Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:

      1.  Environmental  Health Effects Research
      2,  Environmental  Protection Technology
      3.  Ecological Research
      4,  Environmental  Monitoring
      5.  Socioeconomic Environmental Studies
      6.  Scientific and Technical Assessment Reports (STAR)
      7,  Interagency Energy-Environment Research and Development
      8.  "Special" Reports
      9.  Miscellaneous-Reports

This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate .instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia  22161.

-------
                                             EPA-600/2-78-208
                                             December  1978
                DEMONSTRATION OF EROSION
                           AND
               SEDIMENT CONTROL TECHNOLOGY

             Lake Tahoe Region of California
                           by

                    Charles A. White
                     Alvin L. Franks
     California State Water Resources Control Board
            Division of Planning and Research
              Sacramento, California  95801
             Demonstration Grant No. S803181
                    Project Officers

                      Hugh Masters
                      Richard Field
            Storm and Combined Sewer Section
              Wastewater Research Division
Municipal Environmental Research Laboratory (Cincinnati)
                Edison, New Jersey  08817
       MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
           OFFICE OF RESEARCH AND DEVELOPMENT
          U.S. ENVIRONMENTAL PROTECTION AGENCY
               .  CINCINNATI, OHIO  45268

-------
                                 DISCLAIMER
This report has been reviewed by the Municipal Environmental Research Labora-
tory, U. S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views and
policies of the U. S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or recommendation
for use.
                                      ii

-------
                                FOREWORD
 The  U.S.  Environmental Protection Agency was created because of increasing
 public and governmental concern about  the dangers of pollution to  the
 health and welfare of the American people.  Noxious air,  foul water, and
 spoiled land are  tragic testimony to the deterioration of our natural en-
 vironment.  The complexity of  that environment and the interplay between
 its  components require a concentrated  and integrated attack on the problem.

 Research  and development is that necessary first step in  problem solution
 and  it involves defining the problem,  measuring its impact, and searching
 for  solutions.  The Municipal  Environmental Research Laboratory develops
 new  and improved  technology and systems for the prevention, treatment, and
 management of wastewater and solid and hazardous waste pollutant discharges
 from municipal and community sources,  for the preservation and treatment
 of public drinking water supplies and  to minimize the adverse economic, so-
 cial, health, and aesthetic effects of pollution.  This publication is one
 of the products of that research; a most vital communications link between
 the  researcher and the user community.

 This erosion control project and report is intended to assist the State
 and  Regional Boards and other responsible entities in abating sediment and
 erosion problems in existing residential developments and insuring that
 adequate pollution control technology  is incorporated into future develop-
 ments.  Only through vigorous control  of existing pollution problems and
 the  absolute prevention of future problems from developing can high quality
waters be protected for current and future generations.
                            Francis T. Mayo
                            Director
                            Municipal Environmental Research
                            Laboratory
                                 iii

-------
                                  ABSTRACT
A three-year project was conducted by the California State Water Resources
Control Board to determine methods of preventing and correcting erosion
problems which severely effect the quality of the waters of the State of
California   Two-project sites were chosen in the vicinity of the Lake Tahoe
basin in California.  One project site, Northstar-at-Tahoe, is a well planned
and constructed residential-recreational development constructed in the early
1970s.  The cost of extensive predeveloped planning and erosion control at
Northstar is currently less than $400 per developed unit or residential lot.
With ultimate planned build-out, costs are expected to be reduced to $220 per
developed unit.  The other project site, Rubicon Properties - Unit No. 2, is
an extremely poorly planned and constructed residential subdivision develop-
ment constructed in the late 1950s and early 1960s.  The cost of complete
corrective erosion control at Rubicon Properties would range from $1,000 to
$3,000 or more per residential lot.

At both project sites, extensive hydrologic and water quality monitoring
programs were conducted to determine erosion rates and their impact upon aqua-
tic ecosystems.  Monitored parameters  included precipitation, snow depth,
stream flow, suspended sediment and concentration, and benthic macroinverte-
brate communities.  Postdevelopment erosion rates at Northstar are estimated
to be 100 percent above predevelopment levels, resulting  in only minor  pertur-
bations of  the benthic macroinvertebrate community of West Martis Creek.
Postdevelopment erosion rates within Rubicon Properties are estimated  to  be
over  10,000 percent above predevelopment levels,  resulting in  up to 99  percent
 destruction of  the  benthic macroinvertebrate community  in Lonely Gulch Creek.
At both project sites,  extensive  demonstrations  were made of predevelopment
 planning  concepts,  construction techniques,  and  corrective measures which may
 be  used  to  substantially  reduce erosion and  sedimentation problems  associated
 with developments which are  typical to the subalpine  to alpine Lake Tahoe
 region of California.  Analyses were made to determine  cost  and effectiveness
 of the various erosion control techniques which were  demonstrated at  the
 project sites.

 This report was submitted in fulfillment of Grant No.  S803181-01 by the
 California State Water Resources Control Board under  the partial sponsorship
 of the U. S. Environmental Protection Agency.   This report covers the period
 from July 4, 1974,  to July 4, 1977, and work was completed December 31, 1977.
                                       iv

-------
                              TABLE OF CONTENTS
Section
 II

III
 IV
 ^i*-                                                       Page

 Foreword	                        ...
 Abstract	
 Figures 	      	       ^"V
 Tables	'."...!!!!.!.!!....!..!."
 Acknowledgements 	...'...       	

 INTRODUCTION 	

 A.  Project Sites 	,	           3

     1.   Northstar-at-Tahoe 	           o
     2.   Rubicon Properties 	      *       r

 B.  Demonstration of Erosion and Sediment Control
       Technology 	                  q

 CONCLUSIONS AND RECOMMENDATIONS	      10

 PREDEVELOPMENT  PLANNING AND PRELIMINARY SITE ANALYSIS
   AT NORTHSTAR	/	            16

 A.   Introduction 	                  lg
 B.   Planning Team Identification 	1!!!!!!!!!!!'!!!       18
 C.   Evaluation  of the Prime Physical Features'and	
      Conflict  Analysis  	       21

     1.  Vegetation  	           21
     2.  Geology and  Soils  	!!!!!!!!!!!!      25
     3.  Drainage	    	*"      2 5
     4.  Slope	                     07
     5.  Exposure and  Snow Depth  	\'f'm      27
     6.  Conflict  Identification  Summary	'.'.'.      29

D.  Recommended  Conflict Mitigation Measures 	       32
E.  Revised Site  Selection	.!!!."!!      36
F.  Ski Slope Suitability Model  	.'!.*!.*.*.'!.'.'.*!!!      36
G.  Final Development Plan	!!!!!!!*""*      An

DEVELOPMENT CONSTRUCTION CRITERIA FOR NORTHSTAR  	      45

A.  Logging Controls and Ski Trail Clearing 	      45

-------
                              TABLE OF CONTENTS
                                 (continued)
Section   Title
          B.  Site Specific Soils Analyses ......................
          C .  .Environmental Impact Reporting ...... ..............      4°
          D.  Planting and Revegetation Management Program ......      54
          E.  Criteria Summary ........ . .........................      63

   V      NORTHSTAR-AT-TAHOE:  A WELL PLANNED AND CONSTRUCTED
            RESIDENTIAL-RECREATIONAL DEVELOPMENT ................      66

          A.  The Ski Area .- ....................... . ........... •••      66
          B.  Street and Parking Lot Construction ...............      70
          C.  Condominiums ,. Village Center, and Homesite
                Construction .......... . .........................      ' 2
          D .  Remaining Problems ...... . .........................      ^
          E.  Demonstration of Erosion Control Technology .......      80
          F.  Northstar Cost Summary ... ............ .............      °2

  VI      RUBICON PROPERTIES:  A CLASSIC EXAMPLE OF MASSIVE
            EROSION PROBLEMS DUE TO POOR PLANNING AND
            CONSTRUCTION PRACTICES  ..............................      83

          A.  Erosion Problems ....... . ..........................      °^
          B.  Roadway Construction Problems  .....................      °s
          C .  Storm Water Drainage Problems  .....................      90
          D.  Maintenance Procedure Problems  ....................      91
          E .  Other Problems  ......... . .......................... -     92
          F.  Demonstration of Erosion Control Technology  .......      9^
          G.  Cost and Effectiveness  . . ..........................      97
          H.  Recommended Control Measures  ......................      97

  VII      THE IMPACT OF DEVELOPMENT ON WATER QUALITY ............      101

          A.  Introduction  ......................................
          B.  Water Quality Monitoring Program ..................
          C.  Water Quality  of West Martis  Creek (Northstar)  ....      104
          D.  Water Quality  of Lonely Gulch Creek (Rubicon)  .....      H6
          E.  Water Quality Modeling  of Suspended Sediment
                 Transport  .......................................

              1 . West Martis Creek .............................
              2 . Lonely  Gulch Creek  ............................

                                                                       1 *^R
           F .  Summary and Conclusions ...........................      x J0

 VIII      BEST  MANAGEMENT PRACTICES FOR EFFECTIVE EROSION CONTROL     142

           A.   Introduction ................................... • • •
           B.   Cost  Estimating Procedure .........................      144
                                       vi

-------
                              TABLE OF CONTENTS
                                 (continued)
Section   Title
 IX
 C.   Temporary Sediment Control 	      145

     1.   Impermeable Berms	      147
     2.   Straw Bale Sediment Barriers	      149
     3.   Filter Berms	      152
     4.   Filter Fences  ...,.....;	      154
     5.   Comparative Costs	!|!!!      156

 D.   Drainage Control .............	      157

     1.   Curbs,  Dikes,  and Gutters	      158
     2.   Drop Inlets 	..;	      158
     3.   Drainage Channels 	      160
     4.   Water Bars	..,	      163
     5.   Infiltration Trenches	V	      165
     6.   Sediment Retention Basins  	      168
     7.   Drainage Control,,,Cost-Effectiveness	      170

 E.   Mechanical  Stabilization of Over  Suspended Slopes  .      170

     1.   Curbs and  Dikes for Bench Construction	      171
     2.   Breast  Walls 	      174
     3.   Slope Scaling  and  Overhang Removal 	      180
     4.   Contour Wattling  	..      183
     5.   Other Methods	      190

 F.   Permanent Vegetative Erosion Control  	      192

     1.   Cut Willow Stakes	      193
     2.   Plants	[[[      195
     3.   Seed and Fertilization 	      199
     4.  Mulching Techniques	      209
     5.  Wood Fiber Hydroseeding and Hydromulching	      210
     6.   Straw Mulching	      214
     7.   Chemical Tackifying Agents	      219
     8.  Mulch Nets and Blankets	      223
     9.  Fiberglass Roving  	 	      229

G.  Comparative Erosion Control Costs 	      232
H.  Preliminary Evaluation of Erosion Control
      Effectiveness	      233

INSTITUTIONAL PROCEDURES FOR EFFECTIVE EROSION CONTROL       237

A.  General Waste Discharge Requirements 	      238
B.  Specific Waste Discharge Requirements 	      238
C.  A Case History	      243

                            vii

-------
Section
   X
Title

REFERENCES
APPENDICES
                              TABLE OF CONTENTS
                                 (continued)
Page

247
          APPENDIX A:  Plant Propagation for the Revegetation of
                         Road Cuts and Fills in the Lake Tahoe
                         Basin	•	
          APPENDIX B:  Erosion Control Plot Descriptions 	
          APPENDIX C:  Water Quality and Environmental Monitoring
                         Data .,	
          APPENDIX D:  Sources of Erosion Control Products and
                         Services 	 	
          APPENDIX E:  Glossary	
          APPENDIX F:  Metric Conversions	
                                                            252
                                                            280

                                                            324

                                                            362
                                                            371
                                                            379
                                     viii

-------
                                   FIGURES
Number
                                                                      Pa
   1-1    Erosion Control Project site locations	        /

   1-2    Geology of Northstar-At-Tahoe 	  „               ,
                                                          •   ....        ^

   1-3    Geology of Rubicon Properties 	                    0
                                                       ..........        y

  III-l   The four cornerstones of the Planning Process
            identified in the development of Northstar . 0	       17

  III-2   Northstar planning flow chart 	       19

  III-3   Initial Northstar  proposed development plan  	       20

  III-4   Northstar vegetation density analysis 	       24

  III-5   Northstar slope analysis 	       28

  III-6   Northstar primary  conflicts  	       30

  III-7   Revised Potential  Development Areas  	       31

  III-8   Topographic  base map  of  revised Northstar site	       35

  III-9   "Developable" areas at Northstar identified during
           predevelopment planning  process	       37

  111-10   Ski slope suitability model - computer output	       39

  III-ll   Northstar site  isometrics  	       41

  111-12   Final Land Use Plan for Northstar	       43

  IV-1   Vegetative Mosaic of  the Northstar development site ...      57

   V-l   Existing  land use development at Northstar as of
           July 1977	      68

   V-2   Well revegetated ski run at Northstar using
           rhizominous wheatgrasses	      gg
                                    ix

-------
Number                                                                Pa§e

   V-3    Helicopter installation of ski lift towers reduces
            ground disturbance at Northstar	       69

   V-4    Vegetation from native seed in topsoiled area at
            Northstar after four years 	       71

   V-5    Condominiums at Northstar situated in an area of
            minimum environmental impact with little
            disturbance to surrounding vegetation 	       73

   V-6    Discharge of condominium parking lot runoff to
            downslope undisturbed area at Northstar	       73

   V-7    Rock riprapped check dams protecting an area at
            Northstar disturbed by the underground placement
            of utilities 	       76

   V-8    Erosion problems identified at Northstar 	       77

   V-9    Oversteepened and eroding cut slope adjacent to the
            parking lot at Northstar in the spring of 1975 	       79

  VI-1    Rubicon Properties subdivision on the west shore
            of Lake Tahoe 	       84

  VI-2    Rubicon Properties project site 	       85

  VI-3    Deposition of granitic sediments in Lonely Gulch
            Creek resulting from erosion within Rubicon
            Properties subdivision 	       86

  VI-4    Steep roadways and oversteepened cut and fill slopes
            within Rubicon Properties subdivision, Lake Tahoe
            Basin	       89

  VI-5    Eroded and accumulated sediments at the toe of an
            oversteepened cut slope within Rubicon Properties
            subdivision, Lake Tahoe Basin, during the summer
            of 1975 	       96

  ,VI-6    Oversteepened cut slope after application of
            mechanical and revegetative erosion control
            techniques with an estimated 80-90% effectiveness
            in reducing erosion rates.  Picture taken in the
            summer of 1977 	»	       96

 VII-1    Hydrologic monitoring sites within West Martis
            Creek watershed (Northstar) 	      106

-------
Number                                             ,                   Page

 VII-2    Schematic diagram of water quality monitoring sites
            at Northstar	     107

 VII-3    Streamflow and snow pack water storage as measured
            in West Martis Creek watershed from October 1974
            through September 1976	     109

 VII-4    West Martis Creek macroinvertebrates,  September
            1974	

 VII-5    Lonely Gulch Creek water quality monitoring
            diagram	

 VII-6    Streamflow as measured in Lonely Gulch Creek
            at Gauge No.  5	     119

 VII-7    Lonely Gulch Creek macroinvertebrates,  July 1975  ......     122

 VII-8    Lonely Gulch Creek macroinvertebrates,  December
            !975	      122

 VII-9    Lonely Gulch Creek macroinvertebrates,  June 1976  	      123

 VII-1Q    Lonely Gulch Creek macroinvertebrates,  October
            1976 	      123

 VII-11    Correlation  of  suspended  sediment concentration
            with Streamflow  at Gauge No. 3, West  Martis
            Creek (Northstar)  	0	      128

 VII-12    Suspended Sediment Load in West Martis  Creek
            (Northstar) as estimated by water quality
            model  from October 1974 through September 1976  	      130

 VII-13    Correlation  of suspended sediment concentration
           with Streamflow at Gauges No. 5 and No. 6,
           Lonely Gulch Creek (Rubicon Properties) 	      135

VTI-14    Suspended Sediment Load in Lonely Gulch Creek
            (Rubicon Properties)  as estimated by water
           quality model from November 1972 through
           November 1973 and from June 1975 through
           September 1976	      137

VII-15   Comparison of predevelopment and postdevelopment
           suspended sediment yields at Northstar and
           Rubicon Properties project sites 	      141
                                    xi

-------
Number
Page
VIII-1    Steeply eroding cut slope adjacent to paved roadway
            at the Rubicon Properties erosion control project
            site		     143

VIII-2    Impermeable berms	..     148

VIII-3    Impervious berm installation adjacent to a stream
            channel at the Northstar erosion control project
            site	     149

VIII-4    Eroded soil material discharging to drop inlet ........     150

VIII-5    Straw bale sediment barrier used to control problem
            pictured in Figure VIII-4	     150

VIII-6    Typical straw bale sediment barrier installation
                                                                      1 C T
            design	*	     1:>1

VIII-7    Typical pervious filter berm installation designs .....     152

VIII-8    Filter fence installation adjacent to a stream
            site	     I55

VIII-9    Typical filter fence installation design 	     155

VIII-10   Gully erosion on fill slope at  the Rubicon
            Properties erosion control project site
            resulting from poor drainage  control and
            lack of vegetation	• •	     159

VIII-11   Severe erosion on fill slope at Rubicon Properties
            erosion control project site  caused by a break
            in an A-C dike	;	     159

VIII-12   Typical drop inlet installation designed to settle
            and trap transported sediments  ..,	     160

VIII-13   Corregated metal pipe used to  direct drainage
            across highly erodible fill  slope	     161

VIII-14   Erosion caused by uncontrolled drainage flowing
            across highly erodible fill  area  	     162

VIII-15   Rock lined drainage channel designed to correct
            problem pictured in Figure VIII-14	     162

VIII-16   Water bar installation on heavily traveled dirt
            road at Northstar  ..„	•	     163
                                      xii

-------
 Numb er
                                                                       Page

 VIII-17   Closely spaced water bars on abandoned dirt road 	     164

 VIII-18   Maximum water bar spacing for various slope
             gradients and erosion hazard ratings	     165

 VIII-19   Typical infiltration trench design for percolation
             of storm runoff from impervious surfaces 	     166

 VIII-20   Infiltration trench sizing diagram	     168

 VIII-21   Suspended sediment settling basin for storm
             runoff control.   Continued maintenance is
             required to assure adequate settling capacity 	     169

 VIII-22   Cut slope reworking.  The amount of reshaping is
             dependent upon the slope of the natural terrain
             above the road cut	  .            171

 VIII-23   Sloughed and eroded soil  material at the toe  of
             a steeply eroded road cut at the Rubicon
             Properties erosion control site	      172

 VIII-24   Curb,  gutter,  and  bench design for stabilizing
             the  toe  of a steeply eroding cut slope	      173

 VIII-25   Typical rock breast  wall  design for the toe of
             a steeply eroding  slope 	      174

 VIII-26   Gabion  breast  walls  	      177

 VIII-27   Scaling an  eroding cut  slope	      181

 VIII-28   Contour wattling 	          185.

 VIII-29    Contour willow wattling installation at the
            Northstar erosion  control project site  	      188

 VIII-30   New growth on a successfully planted willow
            stake 	      194

VIII-31   Container plants	>         -jog

VIII-32   Competition between artificially seeded plant
            materials and native shrubs on a topsoiled
            slope at Northstar 	m	     2Q5

VIII-33   Seed and fertilizer placement on a level
            unvegetated area by means of a range drill	     206
                                    xxn

-------
„  ,                                                                   Page
Number                                                                —B—

VIII-34   Wood fiber hydromulching with seed and fertilizer
            in a one-step operation	

VIII-35   Wood fiber hydromulching labor and equipment
            unit cost as a function of amount of mulch
            applied.  Based on Caltrans contracts for
            first half of 1976	     21J

VIII-36   Straw mulch application to fill slope by means
            of a straw blowing machine	

VIII-37   Straw mulch application labor and equipment
            unit cost as a function of mulch applied.
            Based on Caltrans contracts for first half
            of 1976	V'"

VIII-38   Chemical tackifier application labor and
            equipment unit cost when applied as a water
            base slurry with hydromulching equipment.
            Derived from Caltrans contracts for first
            half of 1976  	

VIII-39   Application of a chemical  tackifier over  straw
            mulch  using hydromulching  equipment  	

VIII-40  Manual application of Excelsior R blanket over
             a seeded and  fertilized  cut  slope	«••

 VIII-41   Jute netting  applied to a  seeded  and  fertilized             ^
             slope	»	

 VIII-42   Manual application of paper  fabric  blanket over
             a seeded fertilized and straw mulched severely
                                                                       2.2. b
             eroding cut slope 	•	

 VIII-43   Penstemon plants planted on a slope covered with
             paper fabric which helps retain the soil
             moisture and inhibit erosion until plants are
             well established	      227

 VIII-44   Labor requirements for the manual installation
             of various erosion control netting and
             blankets 	• •	      228

 VIII-45   Application of fiberglass roving with a
             compressed air gun	•

 VIII-46   Hypothetical one hectare steep, eroding,  cut
             slope adjacent to a road  surface 	
                                       aciv

-------
                                   TABLES
Number
                                                                      Page
 III-l    Comparison of initial proposed development areas
            with revised potential development areas 	       32

 III-2    Summary of developable areas adjacent to West
            Martis Creek 	       38

 III-3    Final land use plan summary for Northstar 	0..       42

  IV-1    Species composition of the vegetative subunits
            at Northstar 	       58

   V-l    Northstar development schedule	       67

   V-2    Developed areas and percent of development
            unit type in "developable" areas  	       74

  VI-1    Estimated yearly erosion rates from the
            upper 24.4 hectares of Rubicon Properties
            from 1959 through 1976 	       89

  VI-2    Erosion control costs at the Rubicon
            Properties project site	       9g

VII-1    Average suspended sediment  concentrations
            recorded at  instream gaging stations on
            West Martis  Creek	

VII-2    Results of  Surber sampling  at nine benthic
            macroinvertebrate  stations  in  the West
            Martis  Creek watershed  	

VII-3    Average suspended sediment  concentrations
            recorded at instream sampling site in
            Lonely Gulch Creek above and below
            development	     121

VII-4     Results of Surber sampling at four benthic
           macroinvertebrate stations on Lonely Gulch
           Creek	     124
                                    xv

-------
Number

 VII-5    Suspended sediment correlations for West
            Martis Creek (Northstar)	     129

 VII-6    Postdevelopment suspended sediment contribution
            to West Martis Creek (Northstar) for various
            flow types	    131

 VII-7    Suspended sediment loads to West Martis Creek
            as developed by water quality model 	    132

 VII-8    Suspended sediment correlation for Lonely
            Gulch Creek (Rubicon Properties) 	    134

 VII-9    Suspended sediment contribution to Lonely
            Gulch Creek (Rubicon Properties) for
            various flow types	

 VII-10   Suspended sediment loads to Lonely Gulch
            Creek as developed  by water .quality model  	    138

 VIII-1    Temporary siltation control equivalent
            installation costs	    i56

 VIII-2    Comparative breast wall construction
            equivalent costs	•    179

 VIII-3    Comparative overhang  removal  and  scaling
            equivalent costs	«     183

 VIII-4    Estimated revetment cost  for  stabilization of
            oversteepened  slopes	•	

 VIII-5    Willow staking  equivalent cost 	•

 VIII-6    Equivalent  costs of plants for erosion  control	     200

 VIII-7    Percentage  composition of seed and fertilizer
            mixtures  used at  the erosion control project
             sites 	     202

 VIII-8    Comparative labor and equipment costs for
             various seed and fertilizer application
             techniques	••••     208

 VIII-9    Hydromulching and seeding costs	 y,..     215

 VIII-10   Straw mulching and seeding costs 	     2J.8

 VIII-11   Recommended straw mulch tackifier application rates ....     220
                                      anri

-------
Number

VIII-12

VII1-13


VIII-14
Estimated tackifier cost applied over straw mulch

Equivalent equipment and labor costs for
  installation of mulch nets and blankets 	
Comparative equivalent unit costs for selected
  erosion control methods used on oversteepened
  slopes	
Page

223


230



234
                                    XV1X

-------
                              ACKNOWLEDGEMENTS

The California State Water Resources Control Board,  Division of Planning and
Research, wishes to acknowledge the assistance rendered by the following
project cooperators, without which the erosion control demonstration project
would not have been possible:

     United States Environmental Protection Agency
     California Regional Water Quality Control Board,
       Lahontan Region
     Lake Tahoe Resource Conservation District
     United States Soil Conservation Service
     Burgess Kay, Consultant
     El Dorado County
     The property owners of Rubicon Properties Subdivision,
       Unit No. 2
     Placer County
     Trimont Land Company - Northstar-At-Tahoe
     California Conservation Corps
     University of California, Davis
       —Department of Environmental Horticulture
       —Bixby Work-Learn Program
     Lake Tahoe Community College
     Lake Tahoe Basin Management Unit, United States
       Forest Service
     Weyerhaeuser Corporation
     Conwed Corporation
     Gulf States Paper Company
     Grass Growers Corporation
     Sta-Soil Corporation
     Dow Chemical USA
     Ludlow Textile Corporation
     Eckbo, Dean, Austin, and Williams, Planning Consultants
     Wilsey and Ham, Engineers

 Special  thanks must be accorded to Mr. David  Gilpin  and Mr. Thomas Jopson,
 graduated student assistants from the University of  California, Davis, who
 provided invaluable assistance with  the erosion control field work.
 Mr.  Kenneth Smith,  graduate  student  assistant from the University of
 California, Berkeley, and Mr. Royle  Johnson of the State Water Resources
 Control  Board provided the project staff with assistance in the development
 of a system to model suspended sediment loads at the project sites.
 Mr.  John Baker of  the Regional Water Quality  Control Board, Lahontan Region,
 and Mr.  Craig Lucy, graduate student assistant from  California State
 University, Humboldt, provided the necessary  expertise in  the monitoring and
                                     xviii

-------
reporting of eroded sediment impact on benthic macroinvertebrates at the
project sites.  Mr. Dennis Talbert's assistance with preparation of graphical
material presented herein was of immeasurable value, as was the assistance of
Carla Hancock, Judy Harris, Harkirin Kaur, Pat Lee,  Anna Mori,  Kathy O'Hare
Joy Tabura and Carolee Western from the State Board's Word Processing Center
in the preparation of the manuscript.
                                    xix

-------

-------
                                  SECTION I

                                INTRODUCTION
In July of 1974, the California State Water Resources Control Board (State
Board) was awarded a Demonstration Grant by the United States Environmental
Protection Agency (EPA)  to conduct a three-year project, "Demonstration of
Erosion and Sediment Control Technology".  The State Board chose the Lake
Tahoe Basin vicinity of  the Sierra-Nevada mountains as a candidate for this
demonstration because of the increasing concern over the impact that develop-
ment and construction activities are having in this region.  The-results of
this project will be used by the State Board as a guide to the correction
of existing and the prevention of  future erosion-related water quality
problems within the Sierra-Nevada  mountains of California.

The State Board and California Regional Water Quality Control Board,
Lahontan Region, (Regional Board)  are concerned about the impacts which
erosion and sedimentation from man's activities are having on water quality
and the aquatic environment.  In the Lake Tahoe Basin, water quality related
erosion problems are manifest in a variety of ways even to the casual ob-
server.  The most obvious impact is the increased turbidity during high-
surface runoff conditions, such as periods of snowmelt or rainstorms.
After short, intense summer rainstorms, the office of the Regional Board in
South Lake Tahoe is frequently contacted by irate vacationers and local
homeowners complaining about the unsightly brown water flowing into streams
tributary to Lake Tahoe.  A certain degree of the suspended sediment flowing
to Lake Tahoe is from natural sources.  However, what few people seem to
realize is that land disturbances  associated with the construction and use
of homes, roads, schools, motels,  parking lots, and other facilities which
allow hundreds of thousands of visitors and residents to enjoy Lake Tahoe
each year can vastly increase the  rate of erosion and sediment yield from a
particular area.  As an  example, a study and recent report conducted by the
California Resources Agency finds  that construction and development of
about 30 percent of the  Upper Truckee and Trout Creek watersheds tributary
to Lake Tahoe have significantly increased erosion and sediment yield of
these two streams over what may be considered "natural levels" (1).

Aside from the lowered aesthetic appeal of sediment laden waters,  there are
other more subtle and potentially  more serious effects.  A recent report
published by'EPA identified eroded sediments as constributing to the eu-
trophication or enrichment of Lake Tahoe in at least two ways (2):

-------
     -  By transporting  associated nutrients, such as nitrogen, phosphrous,
        and iron,  to  Lake Tahoe.

     -  By providing  a suspended substrate (or microscopic platforms)  which
        support bacterial growth.

Lake Tahoe is renowned for  its  crystal clarity.  This is primarily due to
its sterile or nutrient  deficient condition which is a direct result of the
small watershed area  to  the water volume ratio of the Lake Tahoe Basin.
The total land surface area which contributes runoff to Lake Tahoe is only
slightly more than 1% times the surface'area of the Lake itself.  As a
result, naturally eroded sediments and nutrients are contributed to Lake
Tahoe at a very slow rate.  Evidence is accumulating, however, indicating
that man-made developments  which surround Lake Tahoe are rapidly acceler-
ating the rate of nutrient  and  sediment transport to the Lake.  This is
particularly noticeable  in  the  littoral or shallow near-shore areas which
initially receive the increased sediment load and attached nutrients trans-
ported from the disturbed watersheds.  In recent years, many Lake Tahoe
shoreline residents and  visitors have complained that rocks in some near-
shore areas are much more "slippery and slimy" than they had been in the
past.  The slime they refer to  is certainly attached algae.  This is verified
by recent investigations indicating that the rate of algal growth in
Lake Tahoe increased 90  percent during the period from 1960 to 1971 (2).

Not only do suspended sediment  laden waters have a definite impact on the
Lake's water quality, they  also have an impact on the aquatic life found in
streams.  The impact on streams flowing in heavily urbanized watersheds
tributary to Lake Tahoe  has been well documented (1,2,3).  At one of the
project sites, aquatic life in  a  stream receiving eroded sediments has been
reduced up to 99 percent.  The  sediment laden waters reduce aquatic life by
two basic mechanisms:

     —  Deposition of suspended sediments

     -  Scouring of the stream beds

Sediment deposition will bury and smother aquatic life, thereby substantially
reducing their numbers.   The scouring effect of heavily suspended sediment
laden waters during runoff periods is roughly equivalent to "sandblasting"
insect larvae and other aquatic life.   Few  species are able to withstand
such a two-pronged attack on their environment.

The Regional Board, the state agency responsible for adopting and enforcing
water quality standards in the California portion of the Lake Tahoe Basin,
is taking a leading role in preventing  degradation of surface waters by
erosion and sedimentation.  In 1975,  the Regional Board adopted water  quality
objectives for all of the Lake Tahoe Basin  which, once achieved, will  limit
the impact that erosion and sedimentation  induced by man's activities  will
have on the Lake Tahoe Basin.

-------
 The problem now facing the State Board, the Regional Board,  and all other
 agencies and individuals interested in preserving the water  quality of  the
 Lake_Tahoe Basin is identifying methods and procedures which may be used to
 eliminate problems of the past, to prevent problems of the future,  and  to
 achieve established water quality objectives.

 Once a method is identified,  the Regional Board can order the developer to
 use specific methods through discharge requirements.   In  contrast to the
 situation with wastewater treatment plants,  California Law (Water Code,
 Section 13360)  permits the Regional Board to prescribe items required,  such
 as subsurface drains,  rock walls,  etc., for  erosion and drainage  control.

 The purpose of the Demonstration of Erosion  and Sediment  Control  Technology
 Project is to provide  a means of identifying the most  cost-effective methods
 and procedures  required to achieve these ends.

 A.  Project Sites

 Two project sites  were chosen as part  of the erosion control demonstration
 project (See Figure 1-1).   Initially,  Northstar-At-Tahoe, a year-round
 recreational-residential  complex north of  the Tahoe Basin in the Truckee
 River watershed, was selected.   Extensive  planning and environmental con-
 cern has been exhibited by its  developers.   The second site,  Rubicon Proper-
 ties Subdivision,  on the west shore^of  Lake  Tahoe, was selected because it
 represented the opposite end  of  the spectrum — a poorly planned, poorly
 constructed,  environmentally  unsound development.

 Both developments  are located well above the typical winter snow line within
 the Sierra-Nevada mountains of California, an area subject to harsh   cold
 winters and warm,  relatively  dry summers.  The vast majority  of the  pre-
 cipitation occurring in the region typically comes in the winter as  snow.
 Brief, but frequently intense, summer rainstorms can cause considerable
 erosion, particularly in disturbed areas.  The vegetation of  the region  is
 extremely fragile and,  once disturbed,  is difficult to reestablished. Many
 oversteepened slopes or disturbed areas have not revegetated  or restabilized
 in more than 20 years.   Grasses introduced for  erosion control, for  example
 may require repeated fertilization in order to  survive. Native plant species,
 while naturally adapted to the climate  and soil conditions of the region
 are slow growing,  difficult to propagate, and do not provide  sufficient  '
 ground cover in many instances.

 1.   Northstar-At-Tahoe

Northstar is ideal  as a project site.   Knowledge gained from  studying  the
development and its water quality impact should be  readily transferable  to
planning and construction activities in other critical  areas with  similar
soils.   As  a result of  thorough planning and  careful construction  practices,
there were  only a few,  relatively minor problem areas remaining after con-
struction of the initial phases of  the  development.

-------
  EROSION

  CONTROL
  LOCATIONS
                                  ra '^y^r^-g
                                  l-'.Jsyv'-. '•/••, 'i*  —-..: y Jahoe Pi
                                  K ' -r> . ^/- ' • --*-« i if
                              , 5 \ HION Xs_.a.iiJ.LES£'._._',iK
                              -* \»J^Jkv^ii^
                                                                         «3
 STATE
    OF
CALIFORNIA,
                                                                        39"CK
                                                                      120 00'
              KILOMETER
               SCALE
                                                STATE  OF  CALIFORNIA
                                          STATE WATER RESOURCES CONTROL BOARD
                                              EROSION  CONTROL
                                                PROJECT  SITES
                                         DEMONSTRATION OF EROSION AND
                                          SEDIMENT CONTROL TECHNOLOGY

-------
Northstar is located on a 1,036 hectare (2,560 acres) tract in the West
Martis Creek watershed tributary to the Lower Truckee River as shown in
Figure 1-2.  The elevation of the development varies from 1,775 meters
(5,823 feet) at the north end of the tract  to 2,625 meters (8,612 feet) at
Mt. Pluto to the south.  There is a ski area with six double chair lifts
and 115 hectares (284 acres)  of cleared ski runs in the upper elevations of
the watershed.  Residential-commercial  complexes are in the middle elevations
with an 18-hole golf course at the lower elevations.

The geology of Northstar and the West Martis Creek watershed is typical of
the northern one-third of the Lake Tahoe Basin and Truckee River watersheds
which are covered by extensive flows of volcanic rocks of Tertiary and
Quaternary age (See Figure 1-2).  Source areas of the older volcanics are
unknown but are believed to be near Mt. Pluto.  Rock units of Tertiary age
consist of volcanic mud flow breccias and flows of andesite and latite.
The flows are extremely resistant to weathering and have only a thin layer
of soil, while the mud flow breccias are less resistant to weathering and
develop a deep soil.  In general, the Northstar-at-Tahoe development was
provided with a relatively stable environment of Tertiary andesite.  The
deep weathering in the mud flow portions provides a thick soil that supports
good vegetation, is relatively stable,  and  relatively pervious.

The upper portions of the watershed are vegetated by a thick, mixed conif-
erous forest.  Middle to low elevations are vegetated by coniferous forest
with mixed sagebrush and manzanita.  Mean annual precipitation is 80 centi-
meters.  Much of the area was extensively logged as was most of the Tahoe
Basin in the 1800's.  Only moderate logging activity has been conducted in
recent decades.  The West Martis Creek  watershed was recently subject to
only selected logging with no clear cutting prior to the construction of the
Northstar development.  The only other  significant predevelopment human
impact within the West Martis Creek watershed was the presence of sheep
herders at the lower elevation.  Although this activity probably had con-
siderable impact on the open meadow and sagebrush lands, remaining impacts
appear to be negligible.  The only evidence indicating the one-time
presence of sheep herders are a few structures and extensive irrigation
canals in the low lands that used to spread the flow from West Martis Creek
over a wide area to support range vegetation.

A complete discussion of the planning and construction methods that went
into the development of Northstar is included in Sections III through V of
this report.  Section VII includes a discussion of the sediment and erosion
related water quality impact of the Northstar development.

2.   Rubicon Properties Subdivision

Rubicon Properties has been in a continual  state of residential lot expansion
and growth since 1945.  In 1960 the final upper portions of the subdivision
were added.  However, even in 1977 only about 50 percent of the 632 lots
are fully developed.  The development runs  from an elevation of 1,898 meters
at the shore of Lake Tahoe to 2,180 meters.  Magnificent views of Lake Tahoe
are a principle reason for the continued expansion of the Rubicon Properties.

-------
              LEGEND
      Qal  - Alluvium
       01  - Lake  Beds
      Qaf - Alluvial Fan
       Qm - Glacial  Moraines
      QPv- Latite (volcanic)
      Tva - Andesite (volcanic)
     	 Rock  Contact
     -—-Fault
       U  -Uplhrown  Side
       D  -Downthrown  Side
       STATE  OF  CALIFORNIA
 STATE WATER RESOURCES CONTROL BOARD
            GEOLOGY
     NORTHSTAR  AT  TAHOE
DEMONSTRATION  OF  EROSION AND
 SEDIMENT CONTROL TECHNOLOGY

-------
Lonely Gulch Creek which flows through the; development, drains a 2.75 square
kilometer watershed reaching to the top of Rubicon Peak at an elevation of
2,799 meters.

In terms of water quality protection and degree of environmental impact,
Rubicon Properties is diametrically opposed to Northstar.  Where Northstar's
developers expended significant effort to construct a well planned develop-
ment, the relative lack of planning at«Rubicon Properties is obvious.
Where construction practices used at Northstar were designed to have minimum
environmental impact, Rubicon Properties was constructed with environmental
disregard.  Where the developers of Northstar continue to exhibit an ongoing
desire to maintain a minimal environmental impact and to correct remaining
minor problems, Rubicon Properties developers have long since sold all
interest in the subdivision and may in no way be held accountable for the
impact Rubicon Properties is having on water quality and the environment of
Lake Tahoe.

The geology of Rubicon Properties is typical of the conditions found in
much of the granitic southern two-thirds of the Tahoe Basin.  The bedrock
of the Rubicon Properties area is granodiorite.  The principal minerals in
this rock are: (1) quartz 15 to 32 percent,  (2) plagioclase 43 to 55 percent,
(3) potassium feldspar 10 to 20 percent,  (4) hornblende 1 to 8 percent,
(5) biotite -6 to 15 percent, and (6)  augite -0 to 0.3 percent.  In this
subalpine climate, the granodiorite weathers quite deeply and is subject to
both wind erosion and erosion from falling water where exposed and not held
in place by vegetation.  Variations in the level of Lake Tahoe in past mil-
lenia have led to the formation of lake shore deposits above the present
shoreline of Lake Tahoe as shown on the attached geologic map (Figure 1—3)•

During the Pleistocene epoch, huge valley glaciers moved down the canyons
along the western side of the Lake scouring away all of the loose rock and
building great piles of morainal debris.   During the period of maximum
development, these glaciers were as much as 300 meters thick and, in some
areas, covered all but the hightest peaks and ridges.  The record of the
advances and retreats of the glaciers is  preserved in these glacial sedi-
ments.  Four main advances are known to be represented along the west shore
of the Lake.

These glaciers were especially important because they scoured away all of
the weathered rock in the Rubicon Properties and exposed fresh rock at the
surface.  Granodiorite disintegrates along the boundaries between mineral
grains so that, although the grains still fit together in their original
position, the mass is loose, incoherent,  and subject to considerable erosion.
The sand and silt, products of rock weathering, are carried into the Lake.

The majority of the Lonely Gulch Creek watershed is vegetated with a mixed
coniferous forest.  Mean annual precipitation is over 100 centimeters.  Very
little human activity was conducted within the watershed prior to the devel-
opment of Rubicon Properties subdivision,  with the exception of extensive
logging which occurred in the late 1800's.  Since the logging activities

-------
                           ^.Itpl
                           ^pm,,w    \
                           *^l«LvtofesJ*l I v'x.    ?.
•mm^tff:',
m(^^wli\
                   i'^r^i
 Ql -Recent Lake Beds
 Qg - Glacial Deposits
 Qm - Glacial Moraines
 Gr -Granite Intrusive  Rock
	 Rock Contact
                    I mil*
                                STATE  OF CALIFORNIA
                           STATE WATER RESOURCES CONTROL BOARD
                                     ,  GEOLOGY
                                  RUBICON PROPERTIES
                           DEMONSTRATION OF EROSION AND
                            SEDIMENT CONTROL TECHNOLOGY
                                                    1-3

-------
were conducted, the Lonely Gulch Creek watershed had an ample opportunity
to return to relatively stable preimpact conditions, prior to the construc-
tion of Rubicon Properties subdivision.

A complete discussion of the Rubicon Properties  development is included in
Section VI of this report.  Section VII discusses the erosion and sediment
related impacts of Rubicon Properties.

B»   Demonstration of Erosion and Sediment Control Technology

In addition to documenting the water quality impacts of the Northstar and
Rubicon Properties developments, major emphasis  of this erosion control
project has been placed on the implementation and demonstration of a wide
variety of erosion control techniques.  At Northstar,  the  demonstration of
specific, in-place erosion control techniques was confined to the few re-
maining erosion problem areas within the development.   A total of 50 plots
was established at Northstar to demonstrate the  effectiveness of a variety
of slope and disturbed area revegetation and stabilization techniques.  At
Rubicon Properties, the erosion problems were not confined to a few isolated
areas but rather encompassed the entire development.  Erosion control demon-
stration work within Rubicon Properties was confined to the worst portions
within the Lonely Gulch Creek watershed.  It is  anticipated that the ef-
fectiveness of the demonstrated techniques will  be reflected by the improved
water quality of Lonely Gulch Creek.   Over 200 separate plots have been
established within Rubicon Properties to demonstrate a  variety of erosion
control vegetation and stabilization techniques,  either singly or in com-
bination.  Section VIII describes the wide variety of erosion control tech-
niques which were conducted as part of this project.  Appendix A describes
procedures for the propagation of plants suitable for the  revegetation of
disturbed slopes in the Lake Tahoe region of California.  Appendix B de-
scribes the specific plot locations at the two project  sites where the
erosion control techniques were demonstrated.

-------
                                SECTION II

                      CONCLUSIONS AND RECOMMENDATIONS
1.  Poorly planned, constructed,  and maintained  developments can result in
    extremely severe erosion and  sedimentation rates, which in turn can have
    a massive impact upon surface water quality.   This is exemplified by high
    levels of suspended sediment, turbidity,  sediment deposition, and the
    destruction of aquatic life in streams whose watersheds contain such
    improper developments.

2.  Adequate technology exists to insure that properly planned, constructed,
   , and maintained developments that cause land  disturbances will have a
    minimum, if not negligible, impact upon  surface water quality from the
    standpoint of erosion and sediment.

3.  In insuring that future construction of  residential and recreational
    developments results in a minimum  amount of  erosion and sediment dis-
    charge to surface waters, the planning concepts of  (1) restricting land
    uses to suitable sites which  are capable of  supporting the particular
    use, (2) minimizing disturbed land surfaces, particularly road cuts and
    fills, and (3) prohibiting land disturbances from encroaching upon
    stream environment zones, are of premier importance.  At a minimum,
    thorough evaluation of a proposed  development  project site should
    include detailed analysis of  the natural vegetation types, vegetation
    density, geology and soils, drainage, and slope.  Erosion and sediment
    control concepts and requirements  identified in the predevelopment plan-
    ning stages must be fully recognized and adhered to during and after
    actual construction to minimize potential problems.

4.  Adequate technology exists to substantially  reduce  the water quality
    impact of poorly planned, constructed, and maintained developments of
    the past.  However, reducing  erosion and sediment production rates
    to predevelopment levels would be  extremely  expensive and difficult
    in some cases.

5.  Adequate regulatory and enforcement tools exist in  the State of
    California, as embodied in the laws of  the State when implemented by
    regulatory agencies, to insure that erosion and sediment control prob-
    lems are prevented in the future and that past problems are corrected.

6.  The lack of sufficient funds  to correct  erosion and sediment control
    problems generated by past activities (prior to the advent of suffi-
    cient environmental controls) is the primary roadblock to the adequate
                                    10

-------
 8.
10
11.
 control of erosion  and sedimentation resulting from construction
 activities.

 One of the erosion  control demonstration project sites, Northstar-At-
 Tahoe, is  a well planned, constructed, and maintained year-round
 residential-recreational development complex.  Potentially adverse
 environmental  impacts of the development were mitigated by careful
 planning,  government regulations, and the implementation of proper con-
 trol measures.  The few remaining isolated sediment and erosion problems
 within the development are primarily the result of departures from the
 strict construction and management controls outlined in the planning
 process.

 The construction of Northstar-At-Tahoe has resulted in less than
 100 percent increase in sediment yield to the West Martis Creek water-
 shed above very low background levels.  The effect of this increase on
 the monitored aquatic life of West Martis Creek has been negligible.
 The sources of this increased sediment yield include a few isolated
 instances  of oversteepened slopes, unrevegetated terrain, uncontrolled
 drainages, and heavily travelled dirt roadways which involve less  than
 0.3 percent of the  total development.  Because of their isolated and
 limited nature, the application of additional erosion control methods
 should further reduce sediment loads discharged from the Northstar
 development.

 The cost of extensive planning activities and erosion control measures
 implemented by the developers of Northstar-At-Tahoe is currently esti-
 mated  to be less than $400 per developed unit (condominiums or resi-
 dential lots).  With ultimate planned buildout,  the cost per developed
 unit at Northstar is estimated to be reduced to approximately $220.
 Thus,  the actual unit cost of effective preplanned erosion control  at
 Northstar is nominal.

 The other erosion control demonstration project site,  Rubicon Properties,
 is a classic example of the extremely poor development practices which
 have been conducted within the Lake Tahoe Basin in the past.   From  the
 standpoints of erosion control, drainage control,  water supply,  roadway
 construction,  land capabilities,  esthetic appeal,  snow removal,  and
 general maintenance, the  upper portion of Rubicon  Properties  is  exem-
 plary of a poorly planned,  constructed,  and maintained development.

 The development and construction of the upper portions of  the Rubicon
Properties subdivision has  resulted in an estimated 10,600 percent
 increase above the natural  background sediment yield from  the area prior
 to the erosion control project.  Evidence exists that  indicates erosion
 rates may have been as high as  100,000 percent above natural background
 rates immediately after construction of  the subdivision in the early
1960's.  The main sources of  the  eroded material are oversteepened
slopes, unvegetated terrain,  uncontrolled drainages, and abandoned dirt
roads which occupy 13  percent of  the land surface within the upper por-
 tions of Rubicon Properties subdivision.   The impact on  the monitored
aquatic life of Lonely Gulch  Creek has been significant.  Monitored
                                     11

-------
              species in the stream have been reduced in numbers by an average of
              70 percent below the development.  Peak instances of species reduction
              have reached levels of over  99  percent.  Species diversities in Lonely
              Gulch Creek below the development have also been adversely affected.

         12.  Had El Dorado County adequately recognized the requirements of their
              own subdivision ordinance in the late 1950's, it is unlikely that the
              upper portions of Rubicon Properties would have been constructed.  For
              example, the county ordinance required that all cut and fill slopes
              adjacent to roadways accepted by the county must be included in the
              legal right-of-way.  Had this been the case at Rubicon Properties, con-
              siderably less land area would  have been available for subdivision into
              parcels (up to 13 percent less  land).  In addition, if the subdivision
              had been constructed in conformance with county ordinances, the main
              problem areas would have remained in single ownership, considerably
              facilitating the solution of the problem.

         13.  One of the major obstacles to effective erosion control at Rubicon
              Properties was the necessity to obtain permission from each of the 129
              individual landowners to gain access to their property for purposes of
              erosion control.  At Northstar, where the majority of the remaining
              problem sites are still owned by the original developer, problem cor-
              rection, when necessary, is  greatly  facilitated.

         14.  The cost of constructing adequate erosion control facilities at Rubicon
              Properties subdivision, such as those implemented as part of the erosion
              control demonstration project,  could be as high as $2,000 per existing
              residential lot if conducted on a commercial  basis.  The additional cost
              of effective drainage control and sediment catchment facilities would
              add an estimated $1,000 per residential lot.  Furthermore, the continua-
              tion of residential building construction within the project site will
              increase the impervious surface coverage from 16 to 36 percent within
              that portion of Rubicon Properties  at full build-out.  Based upon land
              use capability, ideal impervious  coverage should not exceed one percent.
              Even with the implementation of extensive erosion control  techniques,
              the increased runoff from impervious surfaces will create  additional
              erosion problems which will be even more difficult to control.

         15.  The implementation of disturbed slope stabilization techniques to achieve
              control of erosion problems within Rubicon Properties is expected to
              reduce the previously excessive sediment yield rates by about 80 to 90
              percent.  This level of treatment is significant and is roughly analo-
              gous to "secondary treatment" for suspended  solids removal as in a
              sewage treatment plant.  At Rubicon Properties, however, this "secondary
              treatment" would result in erosion and sedimentation rates which are
              still approximately 1,000 percent above natural background levels.  The
              addition of settling basins and sediment  collection facilities at Rubicon
              Properties would probably further reduce  the sediment yield rates by an
              additional 90 percent, which would be roughly analogous to "tertiary
              treatment" of suspended solids removal in a  sewage  treatment plant.  At
              such treatment level, sediment yield rates  at Rubicon Properties would
                                               12
_

-------
 16.
17.
18.
19,
20,
 only be 100 percent above natural background levels and would be similar
 to the low sediment yield rates generated by the Northstar development.

 The cost to the county  for eroded sediment cleanup and maintenance
 within the upper portions of Rubicon Properties subdivision, prior to
 construction of effective erosion control facilities, is estimated to
 have been approximately $11,500 per year.  The cost to the county to
 conduct a project similar to the Demonstration Project at Rubicon
 Properties, would be-$120,000.  Based on the following assumptions, the
 cost of effective erosion control would be amortized over a period of
 12.5 years,  and the additional cost of complete drainage control and
 sediment collection facilities would be amortized over a 20 year period:

      1)    Negligible erosion and sediment control maintenance would be
           required after  such a project.
      2)    Only  maintenance cost savings are ascribed to the cost of
           effective erosion control, with no costs allocated to environ-
           mental protection and enhancement.
      3)    The long-term increased maintenance cost rate is 6 percent
           (27 year ENR  construction index since 1950).
      4)    Money may be borrowed at 8 percent interest.

 Erosion control measures, which may be applied to various erosion prob-
 lems,  are very  site specific.  Depending upon soil type,  slope angle,
 slope length, seepage areas,  exposure,  rockiness, elevation,  and vari-
 ous  control measures, either singly or in combination, may achieve the
 most cost-effective level of erosion control.   Site investigations must
 be made prior to  the implementation and cost estimating of specific
 erosion control projects.

 The  estimated commercial cost of erosion control at Rubicon Properties
 was  approximately  $75,000 per hectare of disturbed slope  surface.   Tech-
 niques  ranged from simple seeding and mulch application with an estimated
 commercial cost of less than $3,000 per hectare to extensive improve-
 ments, including retaining walls,  willow wattling,  plantings,  seedings,
 and mulching  at a maximum estimated commercial  erosion control cost of
 over  $200,000 per hectare of  disturbed  slope surface.   The cost of indi-
 vidual revegetation techniques ranged from $3,000 to  $20,000  per hectare.
 In most instances, considerable additional funds  were required for
 mechanical slope stabilization prior to revegetation.   As  eroding  slopes
 become steeper and longer, the vegetative portion of  effective erosion
 control represents only a small portion of the  total  cost.

 The use of straw mulch with a chemical  or mechanical  tackifier is among
 the most cost-effective of erosion control  and  revegetation techniques
which were demonstrated at the project  site.  The establishment of vege-
 tative cover by using a straw mulch  does  as well, or better,  than other
 demonstrated techniques, some of which  are  considerably more  expensive.

The technique of contour wattling  should  receive  greater use as a means
 to mechanically stabilize and revegetate oversteepened slopes.  The
                                     13

-------
     growth of other types of seeded or planted vegetation is noticeably
     higher on slopes which have received a contour wattling treatment.

21.  The use of rooted  seedlings of native and, in some cases, exotic shrubs
     is an effective means of revegetating and stabilizing disturbed areas
     But is not feasible in many instances due to prohibitively jiigh plant
     production costs.   Currently, commercial production costs of' large quan-
     tities of many types of rooted shrub seedlings range from $.50 to $1.00
     per plant.  Newer, more efficient propagation techniques used as part of
     this erosion control project may reduce shrub production costs to less
     than $.10'per plant.

22.  Effective erosion  control  is extremely labor intensive.  For example,
     82 percent of. the  cost of  commerical willow wattling installation is
     labor cost.  Erosion control costs for large projects may be substan-
     tially reduced by  employing conservation corps workers to perform
     unskilled tasks.  Theoretically, overall costs may be reduced as much as
     45 percent.  The actual average  cost of erosion  control at Rubicon
     Properties, using  conservation corps workers where possible, was $58,200
     per hectare of disturbed  slope surface, which is a 33 percent reduction
     in the estimated commercial cost of such an operation.

23.  Strict adherence to certain existing  county ordinances exacerbates ero-
     sion problems and  leads  to higher  erosion control costs.  For example,
     the requirement that paved road  surfaces must be maintained with at
     least a 7.9 meter width more  than  quadrupled the cost of erosion control
     within certain portions  of Rubicon Properties.   Maintenance of a 7.9
     meter road width led to the  construction of expensive gabion retaining
     walls  ($60-$180 per meter) where a narrower roadway would  accommodate
     curbs, gutters, and benches  at  the toe of eroding cut slopes  ($15 per
     meter).  The total cost to the  county to  conduct an erosion control
     project similar to the Rubicon  Properties project would be reduced by
     25 percent if the need for retaining  wall structures were  eliminated.

24.  Certain state, county,  and utility district maintenance practices
     increase  the severity of existing  erosion problems.  Among them  are:

               The practice of removing accumulated  sediments from the  toe  of
               eroding slopes, thereby  undercutting  the slope,  leads  to  fur-
                ther destabilization.   Better practice would be  to move  exist-
               ing drainage further away from the  toe of  the  slope  or to
                construct retaining structures at  the toe  of eroding slopes.
          -   Washing culverts and drains clogged by eroded  sediments
                increases the rate of downslope sediment  transport.  A better
               procedure would include dry boring or reaming  to remove  sedi-
               ments coupled with proper disposal of the  waste  earthen
               material.
          -    Insufficient snow stakes can cause increased damage to curbs,
                dikes,  gutters, culverts, retaining walls,  and slope toe
               benches by snow removal equipment.
                                     14

-------
Improper disposal of waste earthen material, such as "over-
the-bank" practices, increases sediment transport and hinders
the proper establishment of slope stabilization measures.
The application of road sand to facilitate winter travel, with-
out providing for the adequate removal  of accumulated sand,
further increases the rate at which sediments are discharged
to surface waters.
Cleaning roadways of accumulated sediments by means of water
flushing or simple brushing generally increases the rate of
sediment discharge to surface waters.   A better method is the
use of a vacuum sweeper to clean and properly collect and dis-
pose of the accumulated sediments and waste earthen materials.
                      15

-------
A.
                             SECTION  III

  PREDEVELOPMENT PLANNING AND PRELIMINARY  SITE ANALYSIS AT NORTHSTAR


Intro duction
     Northstar-At-Tahoe was planned as an all-year recreation and resort
     community utilizing portions (1,036 hectares) of a privately-owned^
     10,500 hectare tract north of Lake Tahoe in California.   Northstar s
     facilities include a major ski complex, summer recreational facilities,
     condominium residences, a limited number of lot parcels  for single-
     family dwellings, an eighteen hole golf course, and a commercial
     village center.

     In planning Northstar-At-Tahoe, the developers were guided by a
     philosophy which recognized the unique qualities and ecological
     processes of the landscape and considered them to be the primary
     determinants of the proper form of development.  Considerable effort
     was made in the planning process to insure that the Northstar-At-Tahoe
     Development Plan would not violate the landscape, but rather work with
     it to form a "harmonious relationship between man and environment."  (4)

     The four cornerstones of planning  that were used in the preliminary
     site and feasibility analysis at Northstar were the following  (4)

          1.   Physical analysis
          2.   Market analysis
          3.   Profitability
          4.   Government  coordination

     The interrelationship of  the  four  cornerstones of  the planning process
     used  in  the development of  Northstar is  depicted in Figure  III-l.  The
     evolution of  thorough planning,  as exemplified by Northstar-At-Tahoe,
     is not a straight-line process but a cyclical  one by which  the
     developers were  able  to  continually  reevaluate all criteria as  the plan
     evolved  to  determine  their  validity  and  feasibility and,  thus,  to define
     the directives leading  to succeeding development stages.   The  continual
     reevaluation  of  the four  cornerstones  of planning  led to  the creation
     of an extensive  development which minimized adverse environmental
      impacts  and produced a marketable product.
                                        16

-------
The primary cornerstone of Northstar planning was the comprehensive
physical analysis of the original 10,500 hectare tract.   Preliminary
investigations were conducted to identify which major aspects of the
site's environment, including geology, soils, slopes, drainage, access,
and what types of development could best serve (and be served) by the
natural character of the land.

After identifying the site's capabilities and limitations, the planning
turned to a determination of the public needs and interests for the
types of amenities, activities, and projected land capabilities of the
site.  A market study was conducted to determine what the interests
and needs of the public were for potential types of development
activities such as:

     1.   Condominiums
     2.   Residential lots
     3.   Ski area development
     4.   Natural terrain
     5.   Other recreational activities

As the projected need and interests of the public were identified by the
market study, the profitability of providing the various amenities were
examined.
        SOURCE:. EDAW for Trimont Land Co.

     Pigure III-l - The four cornerstones of the Planning Process
     Identified in the Development of Northstar
                                  17

-------
     The fourth and last of the basic cornerstones  of planning used in
     developing the Northstar project was  close  coordination with local,
     regional,  and state governmental agencies.   During  the late 1960*s
     and early  1970's,  when comprehensive  environmental  legislation and
     ordinances were first  emerging,  the Northstar  developers worked closely
     and cooperatively  with all levels of  government.

     Strict adherence to these planning criteria also provided protection
     to local government.   In many instances,  local government has been
     financially burdened by ill-fated developments, half-finished sub-
     divisions, vacant  lots, scarred  land,  and maintenance headaches.
     While Northstar-At-Tahoe is relatively free of these problems, Rubicon
     Properties, the second erosion control demonstration project site, is
     a perfect  example  of the wide variety of  burdens which are placed on
     local government and on the environment as  a result of inadequate
     planning.   The lack of adequate  planning  at Rubicon Properties will be
     thoroughly discussed in a subsequent  section of this report (see
     Section V).
B.   Planning Team Identification

     In order to  adequately  address  the four  cornerstones of planning, a
     multidisciplinary  team  of consultants was retained by the developer.
     The various  areas  of expertise  included  the following:

          1.    Economics-marketing
          2.    Planning
          3.    Ecology
          4.    Soils-geology
          5.    Planning computer
          6.    Ski-hill planning
          7.    Golf course planning
          8.    Architecture
          9.    Engineering
         10.    Legal

     A flow chart depicting  the sequences of  responsibilities is shown in
     Figure III-2.   Initially,  the consulting engineers and the economics-
     marketing consultants proposed  the preliminary master plan
     shown in Figure III-3 encompassing the entire 10,500 hectare tract.
     This initial planning was  based solely upon an initial market analysis,
     existing site information,  and  cursory site investigation.  The
     initial  proposed master plan was heavily dependent upon the obvious
     physical features  of the land.   From this point on, the various com-
     ponents  of the master plan received intense scrutiny and revision.
     The primary  responsibility of the  planning consultants was to determine
     the feasibility of the  initial  proposed  development plan as determined
     by environmental considerations.
                                      18

-------




















r
8
|
«





>
!
I-
H.I
1







!l
M
»





5
!
i

*







L-il
iil







.•(*










.1
•f


















ll
iff
*T*
i

-! <
ilk
*«
:
!
I
I
•



•
«
•o
c
1
u
4
i
•3
u

j
I



]
•4
1







1
»
11
C
4
i
\

\\\
w^ -
II l

















\
i








S1
"*!'
II
u-







o*-
v o "
tf







i
!i
if







- >•

%







•
I
«







~m
\i
\\









•'









\\
h













%


%
i
















^


!
\
«

j












. »'
S
[8-
1
1
• 3
«8-
i
»«

'• *












|i
h
r
4 c
».s
circuU
»«

c
n
















i
»













»
ii
!l!

,
c •
j!
*«
ID


s












1
\
\

"\
}



-











t
i

1
f




















c
Ml*
5 a. -6 <«


















0
i
i
£






	 %
f
*
""I



%
f

....1
f
























|[
»*•









1
>

*
























                                         SOURCE: EDAW for Trimont Land Co.
FIGURE 111-2.   NORTHSTAR  PLANNING  FLOW   CHART
                        19

-------
   TRUCKEE
                         LAND USE    !
                         LEG EN D
                         RESIDENTIAL
                               .05 DU./AC.
                               .10 DU./AC.
                               .25 DU./AC
                               .50 OU./AC.
                               1.00 00./AC.
                               2.00 OU./AC.
                               3.00 DU/AC
                              IO.OO DU./AC
LAKE
TAHOE
             TAHOE
             CITY
                                 OTHER LAND USES
SOURCE: EDAV/for Trimont Land Co
 o    i     2
^ffi«Sr
SPECIAL RECREATION
           ONTROPERTY
        PROPOSE SCENIC HIGHWAY
            INTERCHANGE
                              FIGURE  IH-3
      INITIAL  NORTH   PROPOSED  DEVELOPMENT  PLAN  -  1967
                                   20

-------
c-    Evaluation of the Prime Physical  Features  and Conflict Analysis  (5)

     The critique  by  the planning  consultants of  the initial proposed de-
     velopment  plan was based  upon"the degree to  which the ecological
     integrity  of  the site would be affected by the proposed development.

     The ecological studies were concerned with vegetation, soils, geology,
     and water  balance of the  property.  A vegetation survey was made from
     aerial photographs of the property.  This, in turn, was related  to
     geologic and  related soil types.  Water balances for the property were
     determined from  climatic  data from weather stations adjacent to  the
     Northstar  property.

     The complexities  of the landscape were separated into individual
     components.   Each ecological  or landscape  component was mapped at
     1:24,000 scale.   This information was evaluated according to its
     suitability for  development.  By  overlaying  the plan on each
     landscape  consideration,  the  areas for which the proposed develop-
     ment conflicted with the  ecological capability or which required
     specific considerations were  identified.   Potential conflicts w&re
     then summarized and identified on separate maps as primary and secondary
     conflicts.  The  composite of  these conflicts indicated the areas of the
     plan,  which should not be developed, and identified those areas which
     possessed  the greatest development potential.

     The ski area  and  base area of the development plan were studied  in
     greater detail.   This enabled jnore extensive analysis of the planning
     determinants,  further enabling these determinants to influence spe-
     cific site planning configurations.

     The following analyses of the vegetation,  soils, geology, and water
     balance were  conducted in order to classify  the information according
     to  its suitability for development.


     1.    Vegetation

          The landscape of the Northstar property is dominated by a range
          of vegetation zones  from the lower elevations of Martis Valley to
          the higher slopes of Mt. Pluto.  A large portion of the beauty
          the site derives from this vegetation and the environment of
          each,  development unit and lot depends upon the type of vegetation
          in which each unit is set.
                «

          -    Broad Vegetation Zones:

               The vegetation  was  divided into major zones on the Northstar
               property by the planners.  The lower elevations along west
               Martis  Creek are in a Sagebrush  and grass vegetation zone.
                                      21

-------
This is in the driest part of the original tract.   Next,
rising in elevation,  one enters a Pine Forest-sagebrush
zone, then a mixed Pine-Fir Forest,  and Fir Forest along
most of the higher elevation ridges.  In addition, there  are
local or "azonal" vegetation types,  such as aspen groves,
meadows, willow thickets, mountain alder thickets, rock-
land, and fire types, such as brush fields and thickets of
young tree regeneration.

Vegetation Types

From the combination of these vegetation zones and the azonal
types related to other variables, a mosaic of vegetation
types result.  This mosaic of vegetation types has an ex-
pression visually in age or size classes of trees, crown
density of trees and shrubs, and on structural elements of
vegetation.  The following classification types were de-
veloped from aerial photographs of the Northstar property.

     Structural Class of Vegetation or Ground Cover Type

          C    Conifer trees
          H    Hardwood trees
          S    Shrubs, i.e. manzanita or sagebrush
          R    Rock
          B    Bare Ground

     Age Class (based on size of crown) of Conifers

          0    Old, greater than 75 years
          Y    Young, less than 75 years
          R    Recent regeneration, less than 15 years

     Density Classes of Crown Canopy  (based on aerial photographs)

          80 - 100%
          60 - 80%
          30 - 60%
           5 - 30%
          less than 5%

The  structural elements of each, vegetation type were placed in
the  denominator of a fractional symbol, while the age class and
two  density symbols  (one for conifer  density and  the other for
total woody vegetation  density) were  placed in the numerator.
Two  examples follow:

          OY22
           CB
                         22

-------
This states that the cover is conifer vegetation (C) with
some bare ground (B); there are two age classes present,
old (0), and young (Y);  and that the old age class is most
abundant (OY).   The first density figure indicates that
total conifer density is 60 to 80 percent crown cover (2),
and that this makes up all the woody vegetation density
60 to 80 percent (2).

          51
          S

This indicates a cover type that is shrub (S),  with less  than
5 percent cover density (5), but 80 to 100 percent woody
vegetation cover (1) made up of brush.

From this vegetation classification, it was possible to
single out vegetation types and vegetation densities for
specific consideration and evaluation as their suitability
for development.  Specific vegetation types are
     Mixed Conifer
     Pine Fir
     Pine - Sagenrush.
     Various
Ponderosa Pine, Jeffrey Pine,
Ledgepole Pine, White Fir, Red
Fir, Incense Cedar

Ponderosa Pine, Jeffrey Pine,
White Fir, Red Fir

Jeffrey Pine, Ponderosa Pine
Sage

Sagebrush - grass enclaves,
Aspen, Willow, Mountain Alder,
Manzanita, and meadow
Of these, only the last category of various species in small
areas was considered highly sensitive to development impact.
The Pine—Sagebrush category was considered less desirable
than the others from a visual standpoint.

Vegetation density was measured according to the percentage of
area covered by the vegetation crown as seen from the air.
The vegetation density map developed from this analysis is
depicted in Figure III-4.
     Less than 5%

     5 - 30%
Primarily open space

Desirable density for development
                        23

-------
                             LAKE
                             TAHOE
SOURCE: EDAW for Trimont Land Co.
                                              KILOMETERS
                      FIGURE ill - 4
       NORTHSTAR  VEGETATION DENSITY ANALYSIS
                            24

-------
               30 -  60%
               60  -  80%
               80  -  100%
2.   Geology and Soils
Acceptable for development since no
more, than 30 percent would necessarily
be removed

Minor development problems since more
than 30 percent would be removed for
intensive development and, therefore,
the remaining vegetation becomes
less stable

Serious development problems since
50 to 60 percent would be removed
with the potential to seriously affect
the ecology of the remaining stand
     All of the Northstar property is dominated by volcanic igneous
     rock,  except for some glacial deposits and alluvial areas in
     Martis Creek Valley.   The  soils which are derived from the
     weathering of these  rocks  vary in depth and development in re-
     sponse to climate, nature  of the bedding, and composition of
     .the original rock.   The higher elevation areas of the property
     are characterized by shallow stony soils.  Such soils are not
     well suited for  development.

     The majority of  the  Northstar. development area is composed
     of brown forest  soils, 1 to 2 meters deep and moderately
     stony.  These soils  occur  on the property generally above 1,950
     meters elevation and below 2,300 meters.  The drier portion of
     the property on  the  Martis Valley side is characterized by
     darker, heavier  soils developed on the andesite rock.  The extent
     of these soils can be related to the occurrence of sagebrush.

     There are local  areas of soils associated with poorly drained
     areas, such as springs and meadows which will be different from
     the other soil types. These meadows and seep area soils have
     high moisture storage capacities (30 centimeters to 60 centimeters),
     and also high nitrogen contents  (approximately 9,000 to 11,000
     kilograms per'hectare to a depth of 1.25 meters).  They are
     highly reactive  and  have a good capacity to absorb applied nutri-
     ent and organic  matter without discharge to groundwater in deep
     seepage effluent.
3.   Drainage
     A water balance made by deducting  expected losses from precipi-
     tation on the property.   Supporting  data was gathered from
                                  25

-------
the records of the Central Sierra Snow Laboratory  at  Donner Summit
and from the weather data at Truckee and Tahoe  City.   The analysis
indicated that the streamflow from the area accounts  only for about
60 percent of the total estimated yield.   Thus,  there must be
considerable subsurface flow from the West Martis  Creek Watershed.
This is not unreasonable considering the nature of the igneous rock
geology and the alluvial fill in the West Martis Creek drainage.

In addition to the water balance information, the  following
stream classification was prepared by the Norths tar planners.
          Intermittent Streams

          Perennial Streams

          Flood Plains
                                        Those with only seasonal
                                        flow
                                        Small streams which flow
                                        throughout the year
                                        Streams with sufficient
                                        flow such that a 25 year
                                        flood must be provided for
                                        with an additional 15
                                        meter easement

Predevelopment surface storm or snowmelt runoff from the area
of the Northstar property was slight.   The soils are very perme-
able and runoff coefficients are low.   Some-concentration of
runoff did occur along skid trails and logging roads but,  in
general, did not exceed the infiltration capacities of the soils.
However, it was acknowledged that there would be a change in the
runoff regime following development, particularly as affected by
impervious surfaces and changes in vegetation density.

The change in surface runoff patterns from the development area
was assumed to be proportionate to the impervious area of roofs
and road surfaces within each subwatershed.  The location of
these impervious areas relative to the infiltration capacities of
intermingled land surfaces was a primary factor influencing de-
velopment concentration and spacing.

The overall objective of the design of surface runoff regulation
at Northstar was to contain runoff in channels or to infiltrate
the water without erosion.  The variation and location of small
runoff surfaces necessitated the design of small drainage systems
which would not overload the infiltration capacities of the soil
nor the flow capacity of natural and artificial channels.

Particular attention was given to points of concentration,  such
as road cuts, road surfaces, roof surfaces, and disturbed soil
areas.  Once the runoff is concentrated into channels,  additional
provision for energy dissipation is necessary due to the increased
flow rates.   Concentration of runoff on newly disturbed soil
                            26

-------
surfaces, such as fill material, was recognized as  a potentially
serious problem.

Slope

Slope steepness is the most important single determinant  for
planning purposes, particularly from the standpoint of erosion
control.  Not only does the cost and, therefore, the feasibility of
construction rise in direct proportion to the slope of the  land
but also consequent erosion and sliding are liable  to prove costly,
visually destructive, and detrimental to water quality.

Slope was categorized accordingly:
          0-6% slope
          7 - 11%
         12 - 15%
         16 - 25%
          Over 25%
This represented the maximum desired
slope for roads under snow conditions

This represented the maximum desired
slope for roads under normal conditions
without snow

This represented the maximum slope
which should typically be considered
developable

'Under specific and exceptional
circumstances, it may be possible to
develop land in this category at very
low densities

Land in this category would not be
developed under any circumstances
The results of the slope analysis are shown in Figure  IIL-5.
In Figure III-5, the darkest areas have slopes greater than
25 percent, while the lightest area is indicative  of 0 to  6 percent
slope.

Exposure and Snow Depth.

From the existing record of snowfall in the area and with  specific
reference to the 1967/68 season,  some general estimates of snow depth
according to elevation for the site were made.  Three  major divisions
were determined to exist
          Below 150 cm
          150 - 230 cm
          Over 230 cm
     Average annual snow depth
     Average annual snow depth
     Average annual snow depth
The effect of snow depth on suitability for development  depended on
more considerations than just elevation.   Wind and  exposure
                             27

-------
                              SOURCE:  EDAW.forTrimontLandCo
NORTHSTAR SLOPE ANALYSIS
                28

-------
     determined the extent of the snow hazard.   Estimated snow depths were
     therefore correlated with an exposure map  to  produce the following
     classifications:
               Below 150 cm
               150 - 230 cm
               150 - 230 cm
               150 - 230 cm
               Over 230 cm

6.   Conflict Identification Summary
 Any direction
 South  facing slope
 East and west  facing slopes
 North  facing slopes
 Any direction
     By comparing the initial  proposed development plan with clear over-
     lays of the various  physical  features,  it was possible to identify
     where major or minor conflicts  occurred between the proposed
     development and  the  land  use  capability of  the Northstar property.
     The significance or  magnitude of  the identified conflicts was de-
     pendent upon the degree to which  problems arising in these areas
     could be ameliorated.   Typically, vegetation types and density,
     soils, exposure,  and snow depth were less serious constraints
     than are slope and major  drainage conflicts.  Where several
     conflicts or development  constraints coincided, then the feasibility
     of development was increasingly reduced.  A composite map showing
     these combined conflicts  compared with  the development plan served
     as a guide  for the best location  for the eventual development of
     Northstar-At-Tahoe.

     In making the composite map (see figure III-6) primary, and second-
     ary conflicts were.considered as follows:
              Primary Constraints
Slope
Drainage
    Areas with conflicts of either or b.oth of these primary constraints
    were considered unsuitable for development.
              Secondary Constraints
Vegetation types
Vegetation density
Soils
Exposure and snow depth
    Conflicts arising from these secondary constraints represented
    variances in cost and design controls rather than absolute
    constraints on the feasibility of development.

    This composite was made and entitled "Revised Potential Development
    .Areas"  (see Figure III-7).  When combined with the initial proposed
    development plan (see Figure III-3), it is apparent that the
    total areas involved in the "potential" and the "proposed"
                                 29

-------
                           LAKE
                           TAHOE
SOURCE: EDAW for Trimont Land Co.
                    FIGURE III - 6
            NORTHSTAR PRIMARY CONFLICTS
                         30

-------
TRUCKEE
    FINAL  LAND
     USE  PLAN
LAKE
TAHOE
 K!LOMETEBS.
                                                     .    LEGEND

                                              CONDOMINIUM GROUP 8 DU./ACRE
                                                    FAMILY 2 DU./ACRE
                                              SCENIC HIGHWAY
                                              COMMERCIAL FACILITIES
                                            ' "J SKI AREA          ,
                                              SITE AREA POTENTIALLY DEVELOPABLE
                                             t; POTENTIALLY  DEVELOPABLE W/RECOM-
                                                MENDED MANAGEMENT CONTROL
                                                SOURCE: EDAW for Trimont Land Co.
                            FIGURE  III-7
      REVISED  POTENTIAL  DEVELOPMENT  AREAS  -  1969
                                 31

-------
                                TABLE III-l
             COMPARISON OF INITIAL PROPOSED DEVELOPMENT AREAS
                 WITH REVISED POTENTIAL DEVELOPMENT AREAS
   Initial Proposed Development

   Revised Potential Development

            Readily Developable

            Developable with Management Controls
                                                    TOTAL
HECTARES

  2,702



  1,285

    604

  1,889
          developments are not drastically different.  Although the revised
          potential  development areas are 30 percent less than the original
          proposed plan,  the main difference involves the relocation of
          development  to  more suitable areas.   (The ski area was not
          considered a part of the development  since its determinants are
          widely different from those of housing, roadways, commercial areas,
          etc.)   Table III-l compares the proposed developable areas
          identified in the initial proposed development plan with the
          potential  developable areas identified after detailed review of the
          environmental cons traints.

D.   Recommended Conflict Mitigation Measures

     Based upon the  evaluation of the prime physical features of the Northstar
     property,  several recommendations were made concerning site selection,
     manner of construction, and  development feasibility.  The recommendations
     were made to guide development construction and lessen the impacts of
     identified environmental  conflicts.

     Riparian Areas.  The riparian areas  are  those along streams and around
     springs where the vegetation is particularly dense due to available water
     supply.  These areas were recommended  to be managed such that development
     impacts would be  minimized.

     1.   Any diversion reducing  water  available  to a  riparian channel should
          be accompanied  by thinning of the trees and  vegetation to within the
          supportable limits  of  the reduced water supply.
                                       32

-------
2.   Trees which may fall and block channels  during  floods,  as well as
     any fallen trees and logs adjacent to channels,  should  be re-
     moved.

3.   Trees which are close to the channel or  in such a  position  as to
     cause floating debris to lodge against them should be marked for
     removal.

4.   The cost of maintenance of riparian vegetation  should be
     covered by returns from harvest of suitable trees.

Aspen Groves.  The aspen groves represent a great asset to the Northstar
development area.  Their continued existence  is dependent  upon adequate
water supply.  Any diversion of water from them was  recommended  to be
conducted with care since a thicket of dead trees could result.  The need
to thin aspen stands which had grown to exceed their water supply was
identified.

Meadows and Willow Thickets.   Meadows such as Sawmill Flat and
the Willow and Beaver Pond area within the West Martis  Creek drainage
represented poorly drained soils,  fairly high in fertility.   The removal
of grazing from them would create a succession toward Willow and Alder
brush.  In order to maintain herbaceous meadow vegetation, it was deemed
necessary to have either planned grazing, late fall  burning,  or  mowing
of these meadows.  The general principle was  that the meadows, as they
existed, were the result of past effects of human use as well as their
natural environment.  To the extent that a change in these conditions
would be brought about by the development,  the meadows  would also change.

Erosion Hazards.  The specific soil and geologic types  determine
the extent of possible erosion problems.   Most erosion  is  the product of
road cut and fill operations.  Road cuts must be kept to a minimum.  The
revegetation of disturbed surfaces with native vegetation  by encouraging
natural invasion or by artificial plantings was recognized as an
absolute necessity.

Fertilization.  Most of the soils of the Northstar property  are
high enough in fertility for native vegetation.   However,  any nonnative
or high density plantings that may be desirable for  slope  stabilization or
local landscaping would require fertilization.   It was  recommended that
this should be done only on those sites where fertilizer application
will not change the quality of water flowing  from the area.

Rocky Areas.  Rocky'areas are found throughout the Northstar property.
These outcrops were expected to inhibit development where  the
rocks were loose, talus material lying at the angle  of  repose; undercutting
and frost would cause slope creep of rock debris.

Drainage.  Drainage channels were to be provided at  the toe  of impervious
areas, such as road cuts or large impervious  surfaces,  such  that gully
                                 33

-------
 formation would be avoided.  This involved lined channels where the
 runoff exceeded the infiltration capacity of the collection area.
 Diversion of drainage to fill slopes or to the intersection of fill
 slopes and natural slope grade was to be avoided unless a lined channel
 was provided.  Particular attention was needed at culvert and ditch
 outlets.  Physical structures for energy dissipation were needed if
 there was insufficient natural capacity at the site to absorb the impact
 of the concentrated flow.  Concentrations of runoff greater than the
 capacity of natural channels required lined channels.  The inlets to
 culverts behind fills required devices to trap debris and sediment from
 entering the culvert.

 High Infiltration Capacity Soils.  The soils of the Northstar property
 all have high infiltration capacities.  They are typically brown forest
 soils developed on andesite and have good structural stability.  As a
 result, the infiltration rates of undisturbed areas are very high.  The
 subsurface drainage is good due to the very permeable geologic strata.
 The main recommendation for large surface runoff concentrations was
 that, insofar as possible, high drainage flows should be directed to
 natural channels.  If high concentrations of surface runoff from roads
 and other similar impervious areas are placed out on slopes of residual
 soil, the water may wash deep new channels into the slopes.  It was
 recognized, however, that small discrete drainage water discharges
 could be easily infiltrated in undisturbed areas adjacent to
 development sites.

 Water Quality.  The good structural stability of the soils found within
 the Northstar property was expected to result in water which clears
 rapidly after storms and generally to have low suspended sediment
 content.  Therefore, any deterioration in water quality due to sediment
 was expected to be related to disturbance mainly in the form of road
 cuts and fills.   It was recommended that fills be well compacted and
 have  drainage regulated so as not to adversely affect the low sediment
 regime of  the streams.

 Slope Steepness.  It was determined that areas of the Northstar property
 with slopes less  than 15 percent may be readily developed.  Slopes
 between 15 and  25 percent should be developed only under exceptional
 circumstances.  All  development should be prohibited  from areas steeper
 than  25 percent.

 Snow Depth.   It was  recommended  that all developments should be
 excluded from areas with greater  than 229. centimeters of snowfall.

 Exposure.   It was recommended that  all  development be prohibited  from
'north facing slopes with greater  than 152 centimeters of snowfall.  All
 other areas would be  able  to  sustain  development from the standpoint  of
 exposure  and snow depth.
                                   34

-------
TOPOGRAPHIC
  BASE  MAP
        OF
 NORTHSTAR
                                                STATE  OF  CALIFORNIA
                                         STATE WATER RESOURCES CONTROL  BOARD
                                                   TOPOGRAPHIC
                                                     BASE MAP
                                        DEMONSTRATION  OF  EROSION  AND
                                         SEDIMENT CONTROL TECHNOLOGY
1 FIGURE NUMBER
III-8
                                  35

-------
Revised Site Selection.

In 1970, based upon the continued reassessment of the  four  cornerstones
of the Northstar planning process (market study,  profitability,
government agency co'ordination, and site analysis),  the Northstar
developers made the decision to reduce the scope  of  the project  to
approximately 10 percent of the original 10,500 hectare tract.   The
reduced Northstar site was almost entirely within the  West  Martis Creek
watershed and entirely outside of the Lake Tahoe  basin.   The West Martis
Creek site was chosen due to location of ideal natural terrain for
a ski area within the upper portions of the watershed  below the  summit
of Mt. Pluto.

It was determined early in the marketings-economic analysis  process,
that the inclusion of extensive ski facilities was essential for
the economic success of Northstar-At-Tahoe.  Thus, the remainder of  the
detailed planning effort was concentrated on  the  1,036 hectare portion
of the original 10,500 hectare tract which contained the  ski bowl and
proposed base facilities.

For the purposes of more detailed planning, a 1:4,800  scale topographic
base map with 15.2 meter contour intervals was prepared from aerial
photographs.  Figure 111-^8 depicts the topographic base maps which were
prepared for the revised Northstar site.  The Northstar planning
consultants then prepared an even more critical review of the
development potential of this area.

Further detailed review and evaluation of the prime  physical features
Cslope, soils, vegetation type and density, drainage,  exposure,  and
visual amenities was made.  Potential development areas were defined as
those areas which could be developed without  any  significant conflict
with the prime physical features of the landscape,  potential development
areas with management controls were areas where conflicts did exist, but
where conflicts represented variances in the  cost of development rather
than absolute constraints on the feasibility  of development.  A
summary of the developable land areas of Northstar within and adjacent
to West Martis Creek is shown in Table III-2.   For the most part, the
ultimate development of Northstar-At-Tahoe conformed quite  closely to the
areas identified in Figure III-9.

Ski Slope Suitability Model

It was determined that the final design of the entire  development must-be
closely linked to the design and location of  the  ski area.  Further  study
of the area involved the use of computers for a more detailed analysis of
the ski hill area and the West Martis Creek watershed  than  would be
achieved by conventional methods.
                                  36

-------
              LEGEND

             DEVELOPABLE LAND
             0%-IS% SLOPE
             DEVELOPABLE LAND
             WITH FOREST
             MANAGEMENT CONTROLS
                            .4
SOURCE: EDAW for Trimont Land Co.
                                                           KILOMETERS
                                                                                 r
         FIGURE   111-9.    "DEVELOPMENT"  AREAS  AT  NORTHSTAR
      IDENTIFIED DURING  PRE-DEVELOPMENT  PLANNING  PROCESS
                                            37

-------
                              TABLE  III-2
                     SUMMARY  OF  DEVELOPABLE AREAS
                     ADJACENT TO WEST MARTIS CREEK
Development Areas

     Potential

     Potential w/Management Controls
                                                 SUBTOTAL
Nondevelopable Areas
                                                 TOTAL
HECTARES




   59.2

   96.0

  155.2



  880.8

1,036.0
  The developers started with the establishment  of.generalized  criteria for
  ski slope suitability based on comments  provided by  a variety of ski area
  specialists.   The criteria developed are a hierarchy of values ranked as
  follows from most important to least important:

       1.   Slope
       2.   Surface water
       3.   Sun intensity
       4.   Snow depth
       5.   Vegetation type and age
       6.   Adjacent to streams
       7.   Vegetation density

  On the basis of this value system,  the developers were able to establish
  a matrix for combining the computerized mapping of the individual
  considerations.  Slope and surface water criteria were of  overriding
  importance, in determining the location and extent of the ski  area.  A
  composite computer printout of the entire hierarchy  of values is
  depicted in Figure 111-10, which portrays a  summary  evaluation of ski
  slope suitability.  The darker portions of Figure 111-10 indicate the
  areas of the land most suitable for ski trail  development.  The lighter
  portions are the least suitable areas.  Those  portions of  the terrain
                                   38

-------
       ski  slope
       suitability
SOURCE: EDAW for Trimont Land Co.
          FIGURE III-10.   SKI SLOPE SUITABILITY MODEL
                           39

-------
     adjacent to the surface waters  of West Martis  Creek were completely
     eliminated from-consideration.   Ultimately,  the ski trails
     crossed West Martis Creek in a  few  locations for purposes of access
     only.

     The ski slope suitability computer  output was  used to design the complete
     system of ski trails which were then  checkejl again in the field.  With
     the ski hill refinement provided by the  computer program, Northstar's
     developers were able to establish the extent and location of a variety
     of development components:  ski lifts, ski lodge and base facilities,
     opportunities for ski-in/ski-out condominiums, and access requirements.

     A variety of additional computer analyses were also conducted to
     facilitate plan layout.  These  are  exemplified by the site isometrics
     analyses portrayed in Figure III-ll.  The site isometrics allowed the
     planners and designers of the Northstar  development to gain a three-
     dimensional appreciation  of  the terrain  of the Northstar property.  The
     views  depicted in Figure  III—11 are looking  to the southwest, up the
     West Martis Creek Valley, from  two  different elevations.

G.   Final  Development Plan

     Based  upon the evaluation of the prime physical features of the Northstar-
     star property and considerations pertaining  to marketability, profits, and
     government agency review,  the final development design for Northstar-
     At-Tahoe was prepared by  the planning team.  As was true for the
     evaluation of the prime physical features leading to final site selection,
     primary (slope and drainage) and secondary (vegetation type and density,
     soils, exposure,, and snow depth) constraints were the main factors guiding
     the final development layout design.  Areas  conflicting with the primary
     constraints were considered  unsuitable for development.  Only in rare
     instances and with additional expense were areas with primary constraints
     developed.

     Initially, the complete development of the Martis Creek watershed area"
     was anticipated to extend over  a period  of approximately eight years and
     include approximately 3,115  condominium-type units and 585 single—family
     0.1 hectare lots.  The planned  land use  includes, in addition to the
     residential use,  a village commercial area,  highway service commercial
     at the project entrance,  ski resort,  golf course, recreation center with
     tennis courts and swimming pool, corporation yard for county maintenance
     equipment, fire and police facilities, water treatment facilities, waste-
     water  reclamation facilities (for golf course  irrigation), ski
     maintenance area,-forest  reserve, and open space area.

     The Big Springs Inn, which serves the skiers at the base of the slopes,
     has over 16,000 square meters of floor area.   This inn contains space
     for multipurpose food and beverage  areas, small ski shops/accessories,
     pubs,  ski school and lockers, offices and emergency living quarters,
                                       40

-------
.- *
  ALTITUIE  .  15
  ALTITHIE  .  S
SOURCE: EDAW for Trimont Land Co.
                      FIGURE III  -  11
             NORTHSTAR  SITi  ISOMETRICS
                            41

-------
                             TABLE III-3

                   NORTHSTAR LAND USE PLAN SUMMARY


                                      HECTARES
RESIDENTIAL
     Single Family Homes
     Condominium Units
             '  SUBTOTAL
COMMERCIAL
     Village Center
     Ski Area
     Highway Service
               SUBTOTAL

UTILITIES

     County Services
     Other
               SUBTOTAL

ROADS AND PARKING

     Condominiums
     Village Center
     Public Roads
               SUBTOTAL

RECREATIONAL FACILITIES

     Ski Trails
     Golf Course
     Other
               SUBTOTAL

TOTAL DEVELOPED AREA

OPEN SPACE

     Ski Area Open Space
     General Open Space
     Private Open Space
TOTAL PROJECT
              PLANNED
   14.7
   21.0
   35.7
    1.2
    4.0
    0.8
    7.0
    3,2
    4.9.
    8.1
   18.2
    4.5
   25.1
   47.8
  131.6
   64.8
    2.4
  19.8. 8

  297.4
  413.1
  281.3
   44.0
  738.4

1,035.8
                          PERCENT
 3.4
 0.7
 0.8
 4.6
ia.2

28.7
                                                                71.3

                                                               100.0
                                  42

-------
                                                      KILOMETERS
SOURCE: EDAW for Trimont Land Co.
   FIGURE  111-12.    FINAL  LAND  USE  PLAN  FOR  NORTHSTAR  -  1970.
                                        43

-------
auxiliary first aid,  decks,  and lounges.   The village commerical
facility development  is utimately planned to include medium and highrise
residential units,  specialty shops, markets, multipurpose food and
beverage areas, and other retail service  areas.  At the present, however,
the village commerical area is less than  30 percent completed, with
10,700 square meters  of floor space.

Fourteen ski lifts, principally radiating from  the Big Springs Inn area,
are planned for the ski area which has a  total  area of approximately
486 hectares.  These  facilities are designed for an ultimate peak-day
capacity of approximately 10,600 skiers.   Only  six lifts and one tow
have been constructed.  The ski facilities are  essentially for the
preferential use of the Northstar-At-Tahoe Project residents; therefore,
the ultimate development concept provides for only a limited number of
day skiers.  Table III-3 summarizes the final planned land use for the
Northstar-At-Tahoe, Martis Creek watershed area.
                                  44

-------
                                 SECTION IV

               DEVELOPMENT CONSTRUCTION CRITERIA FOR NORTHSTAR
The planning process which produced the Northstar  development did not end
once the final layout of the development  had Been  chosen.  Considerable addi-
tional planning had to be conducted to  address potential problems that could
appear during the construction phases of  the project.  Of particular interest
from the standpoint of effective erosion  control were  the various studies and
controls which were developed prior to  the start of construction.  These
included:

          Logging Controls
          Site Specific Soils Analysis
     -    Environmental Impact Reporting
     -    Vegetative Maintenance Recommendations

A wide variety of other preconstruction planning activities were conducted
to address problems pertaining to architectural design, sewage treatment,
water supply, parking configurations, specific recreational amenities, zoning
problems, development phasing, and traffic circulation.  These subject areas
were not critical for the control of erosion problems  and, thus, will not be
discussed.

A.   Logging Controls and Ski Trail Clearing

     The ski area at Northstar was designed to have minimum environmental
     impact.  Only narrow trail areas were cleared for ski runs which were
     typically less than 50 meters wide.   Less than 30 percent of the upper
     watershed was cleared for ski trails.  In most instances, storm runoff
     and eroded materials from the initially disturbed ski trails were dis-
     charged to adjacent undisturbed areas.  This  was  accomplished by two
     methods:

     1.   Sloping the cleared ski trail diagonally, across the "fall line"
          or in a downslope direction.  This allowed storm runoff and other
          drainage waters to be "filtered" through adjacent undisturbed
          areas.

     2.   Water bars and gently graded  contours .were used extensively to direct
          cleared slope drainage to adjacent undisturbed areas.

     Logging and tree removal were required for the siting of development
     structures and for the construction  of ski runs.  Criteria were
                                      45

-------
established by the county to minimize adverse impacts on the terrain and
on water quality.  Logging activities can cause extensive soil disrup-
tion and lead to increased runoff  concentrations from disturbed areas
(6,7,8,9)0  Erosion rates from areas  adversely affected by logging activ-
ities may increase dramatically.   The following criteria were developed
at Northstar, as required by Placer County, to minimize these impacts:

1.   General

     -    The natural ground surface  was disturbed as little as possible
          and rubber tired equipment  was used whenever practicable.

     -    No stumping was permitted except where specified for structural
          siting, hazard reduction, or other related purposes.

     -    Existing slash was disposed of offsite by hauling to a disposal
          area or onsite by gathering and piling for burning.

     -    Existing grasses,  weeds, ferns, and ground cover, such as squaw
          carpet and manzanita, were  left in essentially an undisturbed
          state.

     -    No trail work was  conducted without onsite expert supervision.

2.   Trails and Lift Lines

     -    Falling timber into residual stands was avoided.

     -    Fallen logs, trees, stumps,  and slash were removed from trails.

     -    Rocks over 60 centimeters in diameter were placed to the side
          of trails.

     -    Any projecting boulders  (over 2 meters) were drilled and
          shot with low percentage dynamite.

     -    Berms on roads crossing  trails were flattened on cut side
          and rounded off on lower side.

     -    Small seedlings, buck brush, manzanita, etc., adjacent to
          trails were left in place in order to feather edge.

     -    Decayed,  old," or rotten  downed timber was flattened by a
          tractor or other equipment.

     -    Gouging soil with bulldozer blades was prohibited.  Excavation
          was only allowed to adequately divert potential storm and snow-
          melt runoff.

     -    Logs snaked to a landing were thoroughly delimbed and sectioned
          to minimize damage to residual undergrowth, ground cover^
          and timber.
                                46

-------
      -     Stumps were removed either by splitting or by grinding.   This
           resulted in minimum ground disturbance.

 3.    Areas Between Trails

      -     Dead, damaged, diseased, or leaning trees were removed.

      -     Slash and debris on ground were flattened as much as possible.

      -     Willows, alder, aspen and seedlings in these areas were  left
           intact.

 Site  Specific Soils Analyses

 Prior to  the construction of each subunit of the development, detailed
 soils reports were prepared to notify the design engineers of any
 special problems which might be encountered.  In addition, the soils
 reports provided the appropriate construction criteria which were  re-
 quired in each instance.  The following specific construction criteria
 was provided by the individual soil analyses (10):

 1.    Trenching

      -     Clearing and grubbing was kept to a minimum in such a manner
           that the existing natural appearance would be preserved  or
           reestablished at the end of construction.

      -     Top soil was usually thicker than 0.3 meter; therefore,  top
.	  ...... soil was excavated to a maximum depth of 0.5 meter and stock-
           piled separately for later use as the top portion of the back-
           filled trench.

      -     Check dams were required for erosion control of the backfill.
           They were installed across the trench where the ground surface
           slope along the alignment was greater than 10 percent.  Check
           dams were also installed on the up-hill side of major creek
           crossings to prevent direct discharge to surface waters.
           The check dams were constructed by placing internesting  "sack-
           crete" from 0.3 meter above the top of the pipe to 0.15  meter
           above the ground surface.

 2.    Roadway, Parking Lot, and Condominium Construction

      That portion of the Northstar development which is most heavily
      developed for residential and commercial facilities is located in
      an area having silty top soil containing decaying vegetation  and
      roots, cobbles, and boulders in some areas.  The topsoil is
      underlain by sandy silt with a varying amount of cobbles and
      boulders in brown-yellow tuffs and breccias of volcanic origin.
      The  original roadway alignments were covered by a thin growth of
      grasses in places with localized thick pine needle covering below
                                 47

-------
          the trees  and, in some areas, heavy brush and trees.
          was very light, even in the spring and fall seasons.
Surface runoff
          Only a few major construction difficulties were anticipated.   These
          included excavation in dense layers of cobbles and rocks with occa-
          sional large boulders or bedrock and localized high groundwater
          problems.  The thickness of top soil to be removed and stockpiled
          for later revegetation was determined in the field by the soil
          engineer.  It was kept at a minimum, however, consistent with
          obtaining a reasonably good subgrade.  For estimating purposes, an
          average of about 0.5 meter depth of top soil removal was recommended.

          Proposed cut slopes could be excavated at Northstar up to 2:1 with-
          out creating exceptional erosion problems.  When hard rock was
          encountered, the cut slopes were steepened to 1:1 and even steeper.

          Compacted fill slopes were not constructed steeper than 2:1 and
          care was exercised in draining the surface of the adjacent areas
          away from the slope face.  Where natural slopes were steeper than
          5:1, the surface was benched continuously to provide level steps
          on which to base the fill.  All fill slopes were compacted and
          leveled to provide a surface free of loose material which would
          be subject to erosion or sloughing.

C.   Environmental Impact Reporting

     To provide information to the county on the environmental impacts of
     the various proposed subunits of the Northstar development, a series
     of environmental impact reports were prepared by the development plan-
     ners(ll).  Not only did these reports assist the county in their obli-
     gations of meeting the requirements of the California Environmental
     Quality Act (CEQA) of 1970, but they also made recommendations to the
     developers on how expected problems should be addressed.  The recommen-
     dations made in the environmental impact reports pertaining to erosion
     control for trenching operations, roadways, and parking lot construction
     were similar to those made in the various soil reports mentioned pre-
     viously.  The main thrust of the recommendations pertained to problems
     expected to be encountered in the construction of condominium and
     residential subunits.

     1.   Home Sites and Condominium Areas

          The following criteria were used in determining which sites should
          be developed for private home sites and condominium areas.

          —    Natural slopes should not exceed 15 percent.

          -    The soils must be structurally stable, not excessively stony,
               and free of rock outcrops.

          -    Vegetation density of developable areas should not exceed
               60 percent.
                                     48

-------
-    Development should not violate existing flood plain or wet
     meadow areas.   Existing water courses should not be altered.

The following is a  brief summary  of the environmental impacts
pertaining to erosion control and sediment transport which were
identified for a typical condominium construction site:

    "Some ground compaction does  result from the siting of
     .condominium units.  Rubber tired equipment, used where
     possible, serves to minimize soil disturbance and, thus,
     reduce erosion potential In the siting process.  The
     only major potential for erosion occurs on roadcuts and
     fill areas,.  The surface drainage is slightly increased
     especially in paved areas due to a concentration of
     runoff.  Attention must be given to evenly distribute
     the runoff to  existing natural drainage channels.
     trenches dug for utility and service may  impede, to a
     limited extent, subsurface drainage and create a visual
     scar dividing the surface landscape for a short time.
     Few, if any, areas pose revegetation problems if ade-
     quate precautions are taken during construction (11)."

Recommendations for minimizing erosion control and sediment trans-
port problems for a typical condominium unit included:

-    In those areas where ground cover has been removed due to
     cuts and fills or other construction processes, revegetation
     should take place to reduce erosion and,  secondly, to lower
     dust conditions.

-    All cuts higher than 1.5 meters (.Vertical) should receive the
     following special treatment.

          .    Cuts should be sloped to 2:1 and the upper portion
               of the slope rounded off. A 2:1 slope is necessary
               for adequate replacement of topsoil,

          .    Topsoil should be replaced to a depth of 15 centi-
               meters on these cuts and then compacted with a
               sheepsfoot roller*

          .    The topsoil should be replaced  in the spring of the
               year, allowing for a slight erosion of the exposed
               subsoil, thereby resulting in a surface that will
               greatly facilitate the bonding  of topsoil to sub-
               soil.  At this time, hydromulching with. a. native
               seed content and plantings for  erosion control
               should be conducted.

          .    Cuts that expose rock surfaces  should be left as
               such and treated as rock outcroppings,  Such cuts
                            49

-------
                   should be made at the maximum safe slope and not at
                   the two 2:1 slope required for the replacement of
                   topsoilo

          All fill  slopes should be treated in the same manner as out-
          lined for the cut slopes.  Topsoil should be stockpiled at
          several points along the access road right-of-way that are
          convenient  to the major cuts and fills that are involved.
          This topsoil should be stripped from the road right-of-way
          and cut and fill slope areas that are not excessively stony.

     -    Increased surface runoff must be recognized as an exponential
          result of paving and surfacing.

     -    The increase in water runoff should be directed to natural
          drainage  channels to avert overland travel and resulting
          surface erosion, stream sedimentation, and new surface
          channels.

     -    All equipment should avoid rocky outcroppings due to fragility
          of the vegetation characteristic to them and due to the possi-
          bility of slope creep.

     -    All service utilities should be placed in common trenches to
          minimize  the number of trenches excavated per unit.

     -    Trees to  be preserved should be wrapped, staked, or protected
          by other  means to avoid bark damage during the course of con-
          struction.  A rope barrier around groups of trees or other
          vegetation  would be adequate.  No salt should be used on road
          surfaces  for winter safety, except where the addition of sand
          provides  inadequate safety control.

     -    Where sand  is used on roads for winter safety, adequate catch
          basins should be installed and serviced regularly in order to
          provide for the settlement of particular matter from the pave-
          ment runoff prior to any entrance to Martis Creek or any of
          its drainages.

     -    Care should be taken to avoid aspen and other larger trees
          during construction.

     -    West Martis Creek and any wet areas should not be crossed
          with any  vehicle or equipment during construction.

2.   Foundation Systems

     A further in-depth analysis was prepared to determine the compara-
     tive environmental impacts of post and beam construction as opposed
     to perimeter foundations for condominiums.  Comparisons were made
     from the standpoint of soil disturbance, area disturbance, and
                                50

-------
visual conflicts in areas  of  0  to  15 percent slope and areas of 15
to 25 percent slope.

-    The Disturbance of Soil  for Foundations

     Calculations demonstrated  that the average volume of soil
     removed per unit with the  post and beam construction would
     be 31 cubic meters.  The average volume of soil per unit
     utilizing a perimeter foundation would be approximately
     20 cubic meters, which is  35  percent less than the post and
     beam construction.

-    Disturbance of Soil for  Construction

     Post and beam construction requires a continuous pathway
     4 meters wide around the perimeter of each building group or
     approximately 70 square  meters per unit.  This pathway serves
     both foot traffic and traffic from the 60-ton crane which is
     required for the replacement  of the precast concrete footings.
     The movement of the crane  compacts the soil, necessitating the
     removal of all vegetation  in  the area of the pathway, and
     place in jeopardy all trees that are close to the edge of the
     path.  Perimeter foundations  also require a 4-meter wide path-
     way around each building group.  However, this pathway serves
     only foot traffic and occasional traffic light construction
     equipment which deliver  concrete blocks and reinforcing steel.
     These materials are stockpiled within a 4-meter path for each
     unit.

-    Drainage and Revegetation

     The soils of the Northstar property generally possess high
     ecological suitabilities for  buildings and do not pose many
     problems with regard to  a  change in foundation type.  The
     recovery period for vegetation in these soils is generally
     rapid depending on the extent of the original disturbance.
     The main impact involved with post and beam construction on
     slopes greater than 15 percent is the relative bearing capacity
     of the soil.  Due to the lack of substantial clay layers within
     Northstar, the post and  beam  foundation type is a method in
     which bearing capacity and soil drainage create few problems.

     The perimeter foundation,  on  land with less than 15 percent
     slope, creates less disturbed surface area and ground compac-
     tion during construction than post and beam foundation types.
     The foundation wall serves as a barrier to subsurface and
     surface drainage for the entire 36 meter width of an average
     condominium group.  Due  to the presence of a moderately high
     water table in some units, changes in subsurface drainage were
     expected to occur.  In any seasonally wet area, it was recom-
     mended that subsurface drainage pipe, block spacers or other
     similar means be installed to enable drainage to be continuous.
     In areas where downslope vegetation relies on subsurface water

                            51

-------
     drainage,  this  installation is particularly important to insure
     the stability of  the vegetation.  Surface drainage should be
     directed to  natural  drainage channels.  The soils of the lower
     areas which  support  sage brush and Jeffrey pine contain higher
     percentages  of  clay.   The  subsoil permeability and the soil
     drainage is  generally  slower in these soils and this should be
     accounted for by  the installation of subsurface drains.

     The post and beam construction on land with under 15 percent
     slope was not expected to  hamper the subsurface drainage to
     any extent due  to the  fractured nature of soil.  The majority
     of subsurface drainage through the porous substrata would be
     conducted around  the embedded post.  The construction process
     of digging the  holes and placing the post and beams disturbs
     and compacts the  soil  to some extent but, due to the high rock
     content of the  soil, compaction would not necessarily create
     revegetation or runoff problems.  The post and beam construc-
     tion on land with slopes greater than 15 percent results in
     similar impact  as those on slopes less than 15 percent.  The
     relative erosion  potential increases from slight to moderate
     in these soil types  on areas greater than 15 percent slope
     regardless of foundation type.  Due to the particle size and
     distribution of these  soils, the erosion hazard does not pre-
     sent extensive  problems.   If construction practices are care-
     fully monitored,  there should be no subsequent soil drainage
     or revegetation problems on the site with either foundation
     type.

-    Visual Amenity

     Post and beam construction provides an interesting and esthet-
     ically satisfying design relationship between the building
     and the land.  This  relationship is most appropriate in certain
     situations,  such  as  steep  slopes (15 percent) where perimeter
     foundations  would present  a massive and unpleasant face on the
     downhill side of  the unit; on rocky lands where it would be
     extremely difficult  to excavate for linear foundations or on
     wetlands where  no building contact with the surface is desired.
     In almost every other  situation, perimeter foundations that
     are pleasantly  detailed and planted are as esthetically accept-
     able as post and  beam  construction.  When post and beam con-
     struction is to be used, it does provide the potential for the
     accumulation of debris, vegetative, or other beneath the unit.
     This condition  must  be overcome by active maintenance.

The environmental impact  of post and beam construction is slightly
greater on slopes of 0 to 15 percent impact than that caused by
perimeter foundations. Specifically in the areas of soil compaction
and vegetative disturbance, these particular impacts do not increase
significantly on the steeper slope conditions and can be ameliorated
by thorough construction, supervision, and revegetation of disturbed
areas;  Perimeter foundations on the steepest slopes have the
                            52

-------
     esthetic disadvantage of massive downhill faces.  Also, with param-
     eter foundations,  the amount of surface grading required for the
     satisfactory drainage of surface water around the building creates
     significant constraints in tight areas, such as the space between
     buildings or between buildings and parking lots.

3.   Village Center Commercial Area

     The environmental  impact report prepared prior to the construction
     of the village center commercial area recognized the possibility
     of a substantial impact.  It was recognized that much of the area
     would be paved or  covered by other impervious surfaces.

     The major drainage outlet from the Village Center discharges
     directly to Martis Creek east of the village after passing through
     an energy dissipator.  The channel was rock riprapped at the out-
     fall into Martis Creek to avoid extreme bank erosion.  The total
     runoff intensity for peak storm, calculated for a mean annual pre-
     cipitation of 90 centimeters, was 3,110 cubic liters per second
     with the velocity  of 2.2 meters per second at the point of entering
     Martis Creek.  The major impacts are sand and sediment load from
     road and walk surfaces and, secondly, possible vegetation and lim-
     nological damage if  calcium chloride is added to the sand applied
     to road surfaces for winter safety.  Based on Placer County
     Maintenance Department estimates, the total volume for sand nor-
     mally applied per  year to an area comparable to the village center
     and parking area is  between 14 and 18 metric tons.

     Recommendations given for mitigating adverse impacts due to the
     construction of the  Village Center commercial area included:

     -    In order to insure compliance with the Porter-Cologne Water
          Quality Control Act (State of California) and Northstar's
          internal quality control standards, it is recommended that
          an adequate catch mechanism and energy dissipator, such as
          "bubbleup" catchment basin and sediment pond or other simi-
          lar devices be  installed and serviced regularly in order to
          provide for settlement of suspended sediment prior to outfall
          into West Martis Creek.  There should be no significant devi-
          ation beyond  natural background levels of turbidity and total
          suspended dissolved sediment load.

          The angle and slope of the outfall and the entrance of the
          outfall at Martis Creek should be such that minimum streambank
          erosion occurs  at that point.

     -    All trees not marked for removal during the village construc-
          tion should be  chosen for their vigor as well as placement
          purposes. These trees should be wrapped or protected by other
          means to avoid  damage during construction.  Care should be
          taken to avoid  severe ground compaction or disturbance of tree
                                 53

-------
               roots.  A radius comparable to one-sixth of the tree height
               should be roped off or protected by other means to  avoid  this
               excessive compaction and to allow for moisture and  aeration in
               the root zone.

          -    Pathways and walkbridges should be constructed to control
               vegetation  trampling and damage to creek and natural areas.

          -    Care should be taken to avoid overland flow where such flow
               may result  in accelerated erosion.

               No salt should be used on road surfaces for winter  except
               where the addition of sand proves to be inadequate  for safety
               control.

D.   Planting and Revegetation Management Program

     Vegetation was recognized by the developers and planners as an integral
     component of the Northstar environment (12).  It was also recognized
     that a development of Northstar's scope could not be constructed without
     some initial damage to the native vegetation.  The purpose of the
     Planting and Revegetation Program at Northstar was to insure  permanent
     and rapid recovery of disturbed areas.


                            Vegetative Analysis

     The vegetative structure or "mosaic" was carefully examined and  mapped
     at Northstar.  The various subunits identified ranged from open, wet
     meadows and dry, shrubby areas at low elevation to the Red Fir climax
     communities on the upper slopes.  The criteria which was chosen  to  char-
     acterize the several  subunits included:                <

          -    The dominant species present.
          -    Age classes of the dominant species.
               The presence of species with a capacity to reproduce even when
               shaded by existing vegetation.

     A total of 13 distinct subunits were identified within the West  Martis
     Creek portion of  the  Northstar Creek property:

     1.   The Open, Wet Meadow subunit is recognized by an abundance  of  wet
          meadow grasses,  Clover, Willow, and Alder, with scattered Jeffrey
          Pines.  The history of the subunit is mainly grazing and some  creek
          flooding.  The meadow remains wet throughout the summer, due to
          poor drainage, and supports numerous wildflowers.

     2.   The Riparian subunit is characterized by a narrow zone of wet
          grasses and associated hardwood species of Aspen, Black Cotton-
          wood, Willows, and Alders which create a winding strand of  ri-
          parian protection and habitat for associated fauna.
                                     54

-------
 3.   The Wet Meadow-Forest subunit is in a visible state of  change from
      wet meadow grass, Aspen, Willow, and Alder,  to a mixture with
      Lodgepole Pine and White Fir invading from the exterior boundaries.
      These areas are extremely sensitive due to the dependence on water
      and the number of attractive wildflowers and hardwood species.

 4,   The Sage^Bitterbrush-Mule Ears subunit is the driest unit on the
      property and is characterized by the low-lying shrubs and numerous
      grasses and wildflowers.  It occurs on the dark, heavy, high clay
      containing soils developed from andesitic rock.

 5.   The Jeffrey Pine-Sage-Mule Ears subunit is an open,  dry area
      upslope from the creek and below the more heavily  timbered areas.
      The scattered pines make up less than 40 percent of  the cover but
      contribute significantly to the character of the subunit.  This
      subunit occurs mainly on soil type boundaries from less acid to
      more acidic brown forest soils.

 6.   The Pine-Fir subunit represents an area which was, at one time,
      strictly pine-sage but has now been invaded  by White Fir, man-
      zanita, and associated species.

 7.   The Ceanothus-Manzanita Brushfield subunit is historically related
      to fire and depends upon fire for existence.   The  seeds of these
      species require heat of 200-300° Fahrenheit  to germinate but, once
      established, sprout vigorously and tend to control the site.
      A gradual invasion of the Tobacco Brush and  Greenleaf Manzanita
      by conifers over a 30- to 60-year period returns the site to its
      coniferous cover.  The units on the property  represent  two stages
      of coniferous invasion.

 8.   The latter stage of the Ceanothus-Manzanita Brushfield subunit is
      is characterized by a similar mix of Tobacco  Brush and Green Leaf
      Manzanita with a larger percentage of White and Red  Fir.  Some
      Jeffrey Pine is present as a remnant of the original fire and some
      younger trees have seeded along with the White and Red Fir but have
      not competed as favorably.

 9.   The White Fir-Red Fir-Jeffrey Pine subunit in the early stage is
      characterized by dense thickets of young White and Red Fir and
      Tobacco Brush with some Jeffrey Pine present.  This  subunit is
      generally the result of fire or clearcut logging and is one step
      towards the climax on the successional  ladder.  This vegetational
      subunit usually occurs on deep,  brown forest  soils such as Cohassett.

10.'   The White Fir-Red Fir-Jeffrey Pine subunit in  the latter stage has
      progressed further in succession by shading out more of the bush
      species as well as establishing a lower story of White Fir and Red
      Fir seedlings.   Some of the lower species  present in the pure Red
      Fir forest start to appear in this  subunit under the mature White
      and Red Fir.
                                 55

-------
11,   The Fir-rPine subunit is characterized by an upper story of mature
      White and Red Fir with some Jeffrey  and Sugar Pines and an under-
      story of White and Red Fir.

12.   The Red Fir - White Pine *- Jeffrey Pine subunit occurs above the
      2000 meter elevation and covers  the  majority of the upper ski area.
      Pinemat Manzanita replaces Squaw Carpet as the principal ground
      cover in association with Tobacco Brush and Chinquapin.

13.   The Red Fir forest is the climax community and is characterized by
      heavy densities of Red Fir and small amounts of Chinquapin, Goose-
      berry, and Thimbleberry, in openings where light reaches the forest
      floor.  Red Fir is the only major species tolerant enough to repro-
      duce under its own heavy canopy.

 The locations of each of these subunits within the Northstar Property
 is. shown in Figure IV-1.  The various plant  species which were identified
 within each of the suBunits are listed in Table IV-1.  Once development
 occurred within the various subunits, it  was  recommended that disturbed
 areas should be replanted with species native to  that subunit.

                    Revegetation Recommendations

 The following recommendations were prepared by the Northstar planners  to
 serve as a revegetation guide for areas disturbed during construction:

 1.   Condominiums

      -    Concept

                The condominiums have generally been designed  to  impart
                minimal impact on the site with units clustered  to pre-
                serve  open space.  Native vegetation is  preserved as much
                as  possible.

      —    General  Recommendations

                Remove brush to  minimum of 50 feet from units  for purposes
                of  fire safety.

           Upper  Condominium Hill and Middle Condominium Hill

                 Ground covers should  be Pinemat Manzanita,  Newberry
                Penstemon,  and Squaw  Carpet.
                Planting  should occur after seeding disturbed areas  with
                 grass-legume fertilizer mix with Mule Ears added.
                 Jeffrey Pine, Sugar Pine, and Red Fir are recommended
                 trees.
                 Recommended shrubs are Snow Berry and Thimbleberry,
                 neither of which creates  a major fire problem.
                                  56

-------
                   KEY




        I-OPEN. WET MEADOW



        2-RIPARIAN



        3-FOREST, WET MEADOW




        4-SAOE, BITTERBRUSH



        5-JEFFREY PIME-3A6E




        6-PINE-FIR




        7-MAHZANITA-PINE  (EARLY)




        6-MANZANITA-PINE (ADVANCED)




        9-FIR-PINE  (EARLY)




       10-FIR-PINE  (ADVANCED)



       II-FIR-PINE




       12-RED FIR-WHITE FIR




       13-RED FIR
FIGURE  IV-1.     VEGETATIVE   MOSAIC  OF  NORTHSTAR  DEVELOPMENT.
                                            57

-------
                   TABLE IV-1:
                                SPECIES COMPOSITION OR THE VEGETATIVE
                                SUB-UNITS AT NORTHSTAR
No.
          COMMON
           NAME
        SCIENTIFIC
           NAME
                                                    1234
            SUB-UNITS
         5  6  7   8   9   10  11 12  13
 1White Fir
 2   Red Fir
 3   Yarrow
 4   Columbian Monkshood
 5   Wild Onion
 6   Mountain Alder
 7   Serviceberry
 8   Red Columbine
 9   Pinemat Manzanita
10   Green Leaf Manzanita
11   Sagebtush
12   Lady Fern
13   White Brodiaea
14   White Mariposa Lily
15   Pussy Paws
16   Chinquapin
17   Indian Paintbrush
18   Squaw Carpet
19   Tobacco Brush
20   Rabbit Brush
21   Sierra Thistle
22   Meadow Daisy
23   Sierra Morning Glory
24   Sierra Shooting Star
25   Larkspur
26   Horsetail
27   Queen Anne's Lace
28   Gayophyturn
29   Gilia
30   Cudweed
31   Bigelow Sneezeweed
32   Cow Parsnip
33   Tiger Lily
34   Washington Lily
35   Brewer's Lupine
36   Mint
37   Yellow Mimulus
38   Monardella
39   Penstemon
40   Jeffrey Pine
41   Sugar Pine
42   Western White Pine
43   Lodgepole Pine
44   Rattlesnake Plantain
45   Aspen
46   Black Cottonwood
47   Yellow Cinquefoil
48   Bitter Cherry
49   Pinedrops
50   Bitterbrush
51   Huckleberry Oak
52   Buttercup
53   Sierra Currant
54   Sierra Gooseberry
55   Calif. Wild Rose
56   Thimbleberry
57   Willow
58   Elderberry
59   Snowplant
60   Groundsel
61   Wild Hollyhock
62   Spiked Mallow
63   Meadow Goldenrod
64   Swamp Whiteheads
65   Snowberty
66   Danelion
67   Clover
68   Mule Ears
69   Death Caraas
70   Various Grasses
71   Corn Lily
72   Sulphur Flower
73   Fireweed
Abies concolor
Abies magniflea
Achillea mittefolium   X
Acomitium columbianum
Allium sp.
Almus tenuifoiia       X
Amelanchier almitolia
Aquilegia truncata     X
Arctostaphylos nev.
Arctostaphylos patula
Artemisia tridentata
Athyrium filix-femina
Brodiaea sp.
Calchortus venustus
Calyp tridium urab.
Castanopsis semp.       i
Castilleia pimetorum   X
Ceanothus prostratus
Ceanothus velutimus
Chrysothamnus naus.
Cirslum califomicum
(compositia)           X
Convolvulus villosus
Dedecatheon j effreyi   X
Delphinium scopulorum
Equisetum arrense
Eulophus bolander      X
Gayophytum dittusum
Cilia sp.
Gnaphalium sp.
Helenium bigelovii     X
Heracleum lanatum
Liliun parvum
Lilium washingtonianum
         XXX     XXXXX
                  x  x   y   x  x   x
X  X
X  X
X
X  X
   X
   X
   X
X  X
      X
   X
   X
X  X
      X
      X
    \ X
      X
   X
   X
X  X

   X  X
X  X
X  X
      X
Taraxacum sp.
Trifolium sp.
Wyethia mollis
Zigadensus venen.

Veratrum calif.
Eriogonum umbellatum
Epllobium angustifolium
   X  X
X  X
Lupinus brewerii       X
Mentha arvensis       .X
Mimulus guttatus       X
Manardella nana
Penstemon sp.
PInus Jeffrey!         X  X  X  X
Pinus labertiana
Pinus monticola
Pinus murrayana        XXX
Plantago sp.
Populus tremuloides       X  X
Populus trichocarpa       X  X
Potentilla glandulosa        X
Prunus emarginata
Fterospora androw
Purshia tridentata              X
Quercus vaccinifolia
Ranunculus calif,            X
Rlbes nevadense        XXX
Ribes roezlii
Rosa sp.               X  X  X  X
Rubus parvlflorus
Salix sp.              XXX
Sambucus caerulea
Barcodes sanguinea
Senecio triangularis
Sidalcea reptans
SIdalcea spicata       X
Solidago elongata      X
Sphenosciadium sp.
Symphoricarpos mollis
   X
      X
X  X
X  X
   X
   x'
XXX
X  X
XXX
   X
XXX
   X
      X
      X
            X   X
                  X  X   X   X  X   X
         XXXXX   X   XX
         XXX
                     X   X
            X
         X
         XXX
            X        XXXXX
            X        XX
         XXXXX   X   X
         XXXXX   X   X   XX
         XXX
               X
X  X
XXX
                                        X  X
                                   X          XXX
         XXX
         xxxxx   x   xx   x
            X        XXXXX
                                    X
               X
                     x   x   x  x
            X
               X  X  X   X  X   X
            X                       X
         XXX     X   X
            XX         XX

         XXXXXXX       X
                  X             XX

                  XXX      XX
                     XXXXX
XX     X  X   X   X


XXX     X   X   X   X

X
                                            58

-------
               Tobacco Brush will seed itself naturally into  the dis-
               turbed areas but should not be permitted to  immediately
               take control around the units.

     -    Valley Condominiums

               Plants should be Willow, Alder, Dogwood,  Aspen, and
               Black Cottonwood.
               Willow and Alder may be pruned to maintain shrub forms
               and reduce excessive water loss in  the  soil.
               A grass mix favoring clover should  be seeded in the wet
               areas and the remaining areas  seeded with regular grass-
               legume mix.
               Large groups of Aspen should be thinned and  all decayed
               and nonvigorous trees removed.
               Invading pine and fir should be removed in order to
               preserve the meadow quality of the  existing mosaic.
               No track or heavy equipment should  be used in or tra-
               verse the areas.
          .    Slash and heavy brush should be removed to reduce fire
               hazard, enhance the appearance,  and increase the recre-
               ational use value.

2.   Residential Lots

     -    General Recommendations

               Jeffrey Pine infected with Limb  Rust (Cronartuim filamen-
               tosum)  should be removed.
               White Fir infected  with mistletoe should be removed.
               Slash,  dead, or haggard trees  should be removed.  Small
               rubber tired vehicles should be  used for  this operation
               and no dragging over the surface should occur.   All
               material should be  lifted and  carried off site.
               Existing trees may  be pruned or  removed in small numbers
               to improve appearance and views.
               Ground cover should be reestablished as soon as possible
               after disturbance to reduce dust.
               Pine-Fir subunits should be planted with Jeffrey Pine,
               White Fir,  Squaw Carpet,  and Newberry Penstemon with
               grass-legume mix plus Mule Ears  and Brewers Lupine.
               Fir-Pine subunit should be planted with Jeffrey Pine,
               White Fir,  Pinemat  Manzanita,  and Newberry Penstemon
               with grass-legume mix plus  Mules Ears and Brewers
               Lupine.

3.   Village Center

     -    General Recommendations

               The area should be  planted  and managed for heavy impact
               and use.   Some water may be necessary for irrigation.
                                59

-------
               Red Fir, White Fir, and Jeffrey Pine should be planted.
               Consideration should be given to moving several larger
               trees  for more immediate impact.
               Black  Cottonwood, Aspen, Willow, Alder, Dogwood, and
               Thimbleberry can all be used here but will require
               irrigation.
               Ground cover should be Squaw Carpet, Pinemat Manzanita,
               and Newberry Penstemon.
               Grass-legume mixture with fertilizer should be applied
               to disturbed surfaces.  For areas to be maintained as
               grass, a clover mix should be used but will require
               irrigation.

4.   Living Area Recommendations

     -    Concept

               Maximize the use of native materials for amenity and
               utility purposes to combat undesirable noise, to create
               shelter from wind or visual screening, create shade, and
               regulate circulation with barriers.  Hardwoods and soft-
               woods  should be kept as a mixture, where possible, to
               take advantage of summer and winter conditions (shade,
               snow).

     -    General Recommendations
                                                     t
               Rapid  growing hardwood species, such as Black Cottonwood
               and Aspen,  should be used on moist sites or where water
               is available for an initial establishment period of
               3 years.   Both species are readily propagated in large
               numbers.
          .    Pines  and  firs representative of each vegetation zone
               should be  planted  to replace trees lost in development.
               The maintenance of 30 to 40 percent crown cover density
               is important  to preserve the character of a "forest
               environment."
          .    Barrier plants for visual screening, wind breaks, and
               circulation control should be Alder, Mountain Dogwood,
               and Aspen  in moist areas, and Tobacco Brush and Service-
               berry  where water  is not available.
          .    White  Fir, Red Fir, and Tobacco Brush have dense foliage
               and should be the most useful for noise control.
               Singeing of trees when burning  slash, burn piles will
               cause browning of  needles which will not drop for 2 to 3
               years.  Therefore, burn piles should be established on
               road rights-of-way, building and ski terminal sites, and
               as far from surrounding-vegetation as possible.  Burning
               should occur  only  after a good  fall of snow since the
               snow will  protect  the surrounding vegetation.
                                 60

-------
5,   Road Rights-of-r-Way

     —    General- Recommendations

          .     Cuts  and  fills should be covered with 6 inches of topsoil
               as previously recommended.
          .     When  natural revegetation does not occur, a grass-legume -
               seed  mixture with Mule Ears and fertilizer mix added
               should be applied immediately prior to the first snow
               fall. No watering should be done in the fall due to
               possibility of false germination and resultant loss of
               cover.
          .     Squaw Carpet and Newberry Penstemon should be used to
               an elevation of 1,900 meters.
          .     Pinemat Manzanita and Newberry Penstemon should be used
               over  1,900 meters elevation.
               Other species should be used in accordance with the
               subunit in which the cut occurs.
               Considerations of safety, design, aesthetics, pedestrian
               crossings, and snow removal must be made for each speci-
               fic case.

6.   Trails and Paths

     -    Concept

          .    Generally reduce impact to a minimum while aiding safety,
               usability, and amenities.

     -    General Recommendations

          .    Trails not in the immediate development area (or not of
               first importance for general circulation) should be marked
               and layered with fir bark or moved annually to prevent
               permanent compaction and subsequent erosion channels.
          .    All paths of primary importance in the development areas
               should be hard surfaced and clearly marked to permit snow
               clearance.
          .    Disturbed areas should be treated in the same way as
               for cuts  and fills in road rights-of-way.
               Plant materials should be those most resistant to impact,
               hardy, and prostrate.  Such plants (as selected according
               to the subunit through which the trail passes) include:
               Snowberry, Thimbleberry, Serviceberry, Newberry Penstemon,
               Pinemat Manzanita, and Squaw Carpet.
          .    A self-guided nature trail could be planned to pass
               through  the different ecological subunits with inter-
               pretive  information along the  trail.
                                61

-------
Ski Slopes

—    Concept
     .    Ski runs are areas of bare or partially bare ground which
          should be vegetated to stabilize the slopes, reduce
          soil erosion, maintain the visual character, and minimize
          reradiation and early snowmelt in the spring.

-    General Recommendations

          Pinemat Manzanita, Newberry Penstemon, Tobacco Brush, and
          Squaw Carpet should be planted on the ski trails as soon
          as possible.
     .    Seeding with the same mix as for road cuts should be used
          prior to snowfall.  Seeds of shrubs recommended above
          should be added when available.
     .    Green Leaf Manzanita should not be used and should be
          eliminated when possible  since it does not lie flat
          with snow cover.  The plant will stick through low snow
          cover, hasten springmelt, and present a hazard to skiing.

Golf Course

-    Concept

          The detailed design of the golf course should adhere to
          the natural topography as much as possible in order to
          retain mature trees.   Nevertheless, the golf course devel-
          opment will tlireaten the  Jeffrey Pine-Sage-Mule Ears
          community due to the grading and irrigation.

-    General Recommendations

     .    A drainage reservoir should be engineered to capture
          the irrigation water return flows.  Fertilizer and other
          runoff would seriously alter the creek waters and valuable
          water would be wasted without such a reservoir.
          Since irrigation water will be available, Aspen, Cotton-
          wood, and Jeffrey Pine should be planted.
          White Fir should not be planted.
          A clover mixture should be used within sprinkling dis-
          tance of the groomed fairways.

It was estimated that the total disturbed area requiring revege-
tation following construction of the entire planned Northstar
development would be 65 hectares or about 6.3 percent of the
total 1,036 hectares of West Martis Creek Northstar property.
                           62

-------
          The total number of plants estimated to be required to revegetate
          this area was as follows:
               1.   Ground Covers and Shrubs
               2.   Hardwood Trees
               3.   Conifer Trees
                                  Total
$152,410
  11,280
  22,560
$186,250
     In addition,  it was  estimated that approximately one-half of the dis-
     turbed 65 hectares would also require hydromulching with grasses and
     native seeds.

E.   Criteria Summary

     The planning  process conducted prior to the construction of Northstar-
     At-Tahoe was  extensive.  Many of the problems plaguing other poorly
     designed developments, both past and present, were avoided at Northstar.
     Although costly at first,  the type of predevelopment planning conducted
     at Northstar  is likely to  be relatively inexpensive in the long run. As
     will be discussed in later sections of this report, treatment of erosion
     and sediment  control pollution problems after the fact is extremely
     expensive. In addition, the cleanup of erosion and sediment control
     pollution problems,  once a development is constructed, are many times
     much less effective  than if adequate precautions had been taken initially.

     Dr. Paul J. Zinke, the consulting ecologist to the Northstar development,
     summarized the attributes  of the Northstar development planning in a
     1971 report.   Those  points pertaining to erosion and sediment control
     made by Dr. Zinke are as follows (13):

     1.   There has been  an awareness of the value of the landscape and its
          natural  setting throughout the development of the project.  This
          awareness is an attempt to set economic and ecological objectives
          on a parallel and reinforcing direction.

     2.   Logging  operations for timber harvest in the 1950's were planned to
          maintain a landscape  value that was based on the natural integrity
          of a forest  landscape.  Logging road locations and designs were
          such as  to keep erosion to a minimum.  Logging roads generally
          conform to the  contours of the slopes.  There was no clear cutting;
          only thinning operations allowed.

     3.   Initial  development potentials for the property were recognized as
          being due to outdoor  recreation and a need to maintain a favorable
          environment  established as an economic goal.  The intent was to
          develop  Northstar for a market that would prefer a developed prop-
          erty that is based on a sound environmental ecological basis.

     4.   The maintenance of year-round facilities at Trimont was recognized
          as requiring planning for winter as well as summer ecological
          impact.   Clear  waters and wooded slopes were recognized as being
          principal environmental attributes of the area.
                                     63

-------
 5.    The unique qualities and ecological processes of the landscape are
      primary determinants of the proper form of development in the
      Northstar area.  There is evidence of awareness that the complex
      landscape processes which brought about the present environment
      will also ensure its continued stability if not drastically altered.
      For purposes of ecological study, vegetation, soil, geology,  topog-
      raphy,  and hydrology, all have received separate and complete
      analysis.

 6.    Slope criteria were recognized as being of primary concern in deter-
      mining developable area.  In general, areas of greater than 15 per-
      cent slope were considered inappropriate.  Occasional development
      of areas from  15 to 25 percent was considered possible only in
      exceptional situations.

 7.    Hydrologic and drainage factors were evaluated for the property. A
      water balance  was prepared, identification of stream types was
      made,, and the  characteristics of subsurface aquifers were identified.

 8.    The property north of Lake Tahoe and south of Martis has an ecolog-
      ical integrity that is based on a combination of geology and result-
      ing soils, climate, topography, and finally the vegetation that is
      adapted to these.  The critique of the planning for the Northstar
      property was based upon the degree to which the ecological integrity
      of the site would be affected by proposed development.

 9    Soil criteria  for development were based upon a soil-type map com-
      piled from an  existing soil map for the Tahoe Basin, from the
      geology map for the area, and from field reconnaissance of the
      actual area.   Any limitations or disadvantages for development from
      the soil standpoint were noted.  Areas that would not sustain devel-
      opment were noted as being unsatisfactory.

10.    Conflicts between preliminary development plans and ecological
      integrity of the area were identified.  Adjustments were made to
      arrive at a final plan respecting the integrity of the site.  Con-
      straints were  applied to the development based upon the vegetation,
      soil, slope geology, snowfall, hydrology, and visual impact.  The
      primary constraints on development to protect the ecological integ-
      rity were based on slope and drainage.

11.    Computerized map printout and suitability models have been made for
      the development which takes into account ecological criteria.  The
      computerized maps are on a one-acre basis, and there are individual
      maps for each  of the following ecological criteria.  For vegetation
      type; conifer  age class, vegetation density, water types on the
      site, snow depth, sun intensity maps for winter months, average
      annual sun intensity, visual analysis model, topographic analysis,
      aspect and exposure map, slope map, ski slope suitability map, land
      development suitability model, and ski slope suitability map.
                                 64

-------
12,   Th.e beginning of  detailed planning for the siting of roads,  build-
      ings,  and other improvements in the Martis Valley area has been
      marked by a continuous series of discussions pinpointing and dealing
      with ecological opportunities of the site.

13,   Ski area terrain  at Northstar is less steep than other ski areas.
      The ecological impact at the Northstar development, insofar  as
      erosion is concerned, will'be less than other ski developments due
      to the 1esser steepness 6 f slopes.  Ski areas are being developed
      mainly for intermediate skiers.  Continually, emphasis was placed
      on the location of ski areas on smooth, rock-free terrain having
      enough soil so low cover can become established for erosion  control.

14.   The siting of amenities, drainage works, power lines, and other
      development features in the Northstar Basin area has been done in
      such a way that the alteration of natural environment in the area
      will be at a minimum.

15,   There is every indication that the concern for the environment
      represented by these measures will continue in the future.

 The last point is of extreme importance.  The best planning principles
 could all be for naught if the continuing responsibility for the  impact
 of the development was not properly assumed.  In the case of Northstar,
 the original developers maintain a continuing interest in the develop-
 ment.  Although a small portion of the development is sold to private
 ownership (less than 8 percent)., the vast majority of Northstar will
 continue to be owned and operated by a single responsible entity  (in
 addition to the services provided by the county).  The myriad of  poten-
 tial problems, which were recognized in the planning process, must con-
 tinue to be addressed  during the continued expansion and operation of
 Northstar-At-Tahoe; thus, if the concern exhibited in the planning is
 continued through the  construction and maintenance phases, there  is
 considerable reason to believe that a development, such as Northstar,
 would have minimal, if not negligible, adverse impact upon water  quality
 and the environment.
                                 65

-------
                                SECTION V

                NORTHSTAR-AT-TAHOE:   A WELL PLANNED AND
            CONSTRUCTED RESIDENTIAL-RECREATIONAL DEVELOPMENT
To a considerable degree, the actual construction of the Northstar develop-
ment was closely patterned after concepts developed In the planning stages.
The unique commitment of Northstar's developers to thorough planning and
careful construction has led to a well conceived development which has
minimized any adverse environmental impacts.   Compared to most  other past
and present developments of the Lake Tahoe vicinity,  Northstar-At-Tahoe is
one of the best examples of a well planned and constructed residential-
recreational complex.  As documented in Section VII of this report, erosion,
as measured by suspended sediment transport in West Martis Creek, was held to
about a one-fold increase over very low background levels.   Such an accom-
plishment would be possible only through the most careful planning and con-
struction practices.

The ultimate Northstar plan calls for the construction of 132 hectares of ski
runs, a 68 hectare golf course, 585 single-family 0.1 hectare residential
lots, 3,115 condominium units, a recreation center,  a 1.2 hectare village
commercial center, 10 hectares of utility and maintenance facilities and
48 hectare1of roadways and parking lots.   However,  as of 1977,  less than half
of the originally planned development was constructed.   Additional units are.
to be added as future markets conditions dictate.  Only the construction of
ski runs is essentially complete.  At present only 6 of the 14  originally
planned ski lifts have been constructed and only one-half of the originally
planned 18 hole golf course has been completed.   Of the housing units, about
55 percent of the residential lots have been subdivided while only 25 percent
of the potential condominium units are built  or under construction.  Table
V-l describes the engineering, construction,  and sales sequence of the
presently existing Northstar development units.

A.   The Ski Area

     Only in the most intense rainstorms (greater than 1.5 centimeters per
     hour) and during rapid spring snowmelt is there any significant sediment
     discharge to West Martis Creek from the  ski area.   The primary reason for
     this is the fact that the watershed and  terrain chosen is  highly suitable
     for the development of a ski area.  The  natural terrain is gently sloping
     and the high natural percolation rate of the native soils  prevents signif-
     icant overland flow.  Hence, the potential for significant erosion prob-
     lems was reduced simply by proper site selection.   Nonetheless, erosion
                                      66

-------


Unit
Comdominiums
Homes ites
Commercial Area
. Ski Area
Recreation Center
. Stables
Golf Course
. Utilities
TABLE V-l
NORTHSTAR DEVELOPMENT
Engineering
1971-72
1971-73
1972
1970
1972-73
1973
1971-76
1971-72

SCHEDULE
Construction
1972-74
1972-73
1972-73
1971-74
1973-74
1974
1972-77
1971-73


Sales
1972-present
1973-present
1973-present
1973-present
1973-present
1973-present
1973-present
N/A
problems would have appeared had not careful construction practices been
implemented in the development of the ski area.

In most instances ski runs were cut on less  than 3:1  (horizontal to
vertical) slopes and in diagonal patterns at an  angle to the fall line.
This prevented the accumulation and concentration of  runoff in disturbed
areas.  Rather, any storm and snowmelt runoff from areas disturbed for
ski run construction is discharged to and "filtered"  through, undis-
turbed buffer zones.  On the steeper ski runs which could not be sloped
diagonally across the fall line and natural  drainages,  artificial water
bars and diversion structures were constructed.   These structures effec-
tively divert runoff to adjacent undisturbed terrain, yet only create
gentle rolls on the ski slopes which do not  pose a hazard to skiers.

Where possible, natural low-lying native vegetation was left undisturbed
to provide soil stabilization.  This was accomplished,  in part, by the
almost exclusive use of rubber-tired vehicles for tree removal and
slash disposal.  Those areas where native low-lying vegetation was
heavily disturbed or naturally less dense were reseeded artificially,
the seed mixtures which were employed contained  rhizominous wheat-
grasses and legumes and were irrigated where necessary.

On areas which are clear cut for ski runs, remaining  tree stumps can
pose a hazard to skiing.  Traditionally, the method used to mitigate
this hazard is the use of explosives or bulldozers to remove dangerous
stump material.  This method usually results in  considerable soil
disturbance and can lead to the channelization of storms and snowmelt
runoff.  To avoid this problem at Northstar, all stumps were "flush cut"
where possible.  However, in many cases, flush cut tree stumps left in
place had a tendency to "reappear", due to localized  erosion or cause
rapid melting of snow over the stump, resulting  in hazards to skiers.
To alleviate this problem at Northstar,  without resorting to explosives
or heavy equipment, problem stumps were first split with special
equipment, with the pieces then pulled out using light tractors.  This
                                 67

-------
             DIRT ROADS

      §§§$3  GOLF COURSE
                                                    KILOMETERS
                                 FIGURE V-1.
EXISTING LAND USE DEVELOPMENT  AT NORTHSTAR  AS  OF JULY,  1977.
                                       68

-------
Figure V-2.  Well revegetated ski run at
Northstar using rhizomimous wheatgrasses
Figure V-3.  Helicopter installation of ski lift
 towers reduces ground disturbances at Northstar
                  69

-------
     procedure substantially  reduced  the  amount of disturbed soil yet
     provided an easier-to-maintain,  obstacle-free ski run.

     In most instances,  ski lift towers were  installed by rubber-tired over-
     land vehicles.   Although some disruption occurred, it was not extensive
     due to the usually  gentle terrain in which they were installed.  In
     order to prevent extensive disruption  in critical areas, helicopter
     construction was employed for the erection of a ski lifts which
     traverses steeper,  more  erosion  prone  terrain.  By eliminating all heavy
     equipment, substantial disruption of the natural terrain by vehicular
     traffic was prevented.

B.   Street and Parking  Lot Construction

     In most developments,  nonrevegetated and oversteepened cut and fill
     slopes associated with road and  parking  lot  construction are the primary
     source of eroded sediment material contributing to water quality problems.
     Improperly controlled  runoff from the  impervious road surfaces frequently
     aggravates the problem.   Although the  majority of excess sediment trans-
     port at Nort-hstar appears to also derive from these sources, the problem
     is much less severe than frequently  encountered in other developments.

     Considerable attention has been  paid to  the  reestablishment of vegetation
     on the cuts and fills  adjacent to the  roadways and parking lots at
     Northstar.  Although the developer did not strictly employ all of the
     recommendations made in  the "Northstar Planting and Revegetation Manage-
     ment Program" described  in Section IV, considerable effort was made  in
     reestablishing vegetation on disturbed slopes.  The primary vehicle  to
     accomplish this was the  practice of  topsoiling.  Prior to the excavation
     for a roadbed or parking lot site,  the upper 0.25  to  0.50 meters of
     natural topsoil was stripped and stockpiled  in a. adjacent storage area.
     Care was taken to insure that the topsoil material would not be stock-
     piled in areas subject to concentrated storm or  snowmelt runoff or other-
     wise potentially threaten the water  quality  of West Martis Creek.  Once
     the roadway or parking lot was fully excavated,  the topsoil was replaced
     on the adjacent exposed  cut and fill slopes.  In most cases, the cuts
     were no steeper than 1%:1  (horizontal  to vertical) and the fill slopes
     no steeper than 2:1.  In all cases,  soil excavated from  one of the
     vegetation subunits identified in the  "Northstar Planting and Revegeta-
     tion Management Program" was replaced  in the same  subunit.  This insured
     that propagation of native plants from seeds contained in  the topsoil
     would not be in conflict with the natural vegetation  of  each subunit.
     Furthermore, native seeds had a better opportunity to germinate and
     survive in zones of their preferred  habitat.  Approximately  7,800 cubic
     meters of topsoil were required to cover 4.7 hectares of disturbed
     slopes at Northstar.  The average unit cost of  the complete  topsoiling
     operation was $4 per  cubic meter.

     Generally, reestablishing native vegetation by stockpiling was very
     successful.  In a  few instances, slopes which were too steep  to be
     properly  topsoiled were  left bare.   In other instances,  the  topsoil
                                      70

-------
          Figure V-4.   Vegetation from native seed in
          topsoiled area at Northstar after four years
site was too dry or there was insufficient seed material  to  generate
satisfactory growth.  In these cases,  various planting  techniques were
demonstrated by the Soil Conservation Service (SCS)  under a  cooperative
agreement with the Northstar developers.   Demonstrated  methods  included
the following:

     1.   Hydromulching of slopes with various grass and  legume seed
          mixture.

     2.   The planting of native and nonnative shrub seedlings.

The location and description of these demonstration seedings and plant-
ings are included in Appendix B.

Considerable effort was also expanded on the adequate control of runoff
and drainage from impervious road and parking lot surfaces.   Where
possible, runoff is collected from impervious surfaces  in small amounts
and discharged at numerous locations to undisturbed areas where the
native soils are sufficiently pervious to allow complete  percolation.  In
areas where complete percolation is limited by local soil conditions or
the amount of runoff is extremely high, drainage waters are  collected
in nonerodible rock-lined drainage swails and discharged  directly to
West Martis Creek.  The former method of percolation is far  superior.
The erosion control project staff was unable to locate  any discharges of
this nature which exceeded the capacity of the soil or  caused erosion
problems.  In those locations where discharges to undisturbed areas
                                  71

-------
     were used, the drainage waters would have to  travel  overland for 100
     meters through heavily vegetated terrain before reaching  downslope
     dis turbances.

     Direct discharges to West Martis Creek,  whenever monitored, clearly
     resulted in lower stream water quality.   As documented  in Section VII,
     however, these discharges do not appear  to have harmed  the aquatic life
     of West Martis Creek.   In most instances,  the sediment  discharged to the
     creek in this  manner was not eroded  from the  rock-lined drainage swales
     but was of some other origin.   Typically,  sediments  were  transported to
     the swales from eroding slopes and from  winter road  sand.  Without
     settling and/or percolation facilities,  suspended  sediments, once eroded,
     are readily transported to West Martis Creek  by the  artificial drainage
     swales at Northstar.

C.   Condominiums,  Village Center,  and Homesite Construction

     The primary reason potential erosion and sedimentation  problems were
     held to a minimum at Northstar was that  the majority of the development
     was confined to the portions of the  West Martis Creek watershed which
     were most amenable to development.   Ideally,  as identified by the
     Northstar planners, this meant restricting construction of commercial
     and residential buildings to areas with  less  than  15 percent natural
     slope or with  insensitive vegetation types.   However, the portion of
     the property which conformed to this criteria was  fairly  limited.  Thus,
     the areas which were actually developed, or are planned for development,
     extend somewhat beyond the area defined  as "developable"  or "developable
     with forest management controls" (see Figure  III-9).  A summary of
     development confinement to areas defined as ideally  developable is
     presented in Table V-2.   As indicated in the  table,  fully 30 percent
     of the existing development (excluding the ski area, golf course, and
     roadways) are  beyond the boundaries  of what was originally defined
     "developable".   However,  in all cases, building construction has not
     taken place on terrain steeper than  25 percent,  with the  vast majority
     occurring on terrain less than 20 percent  grade.   Based on the water
     quality monitoring program discussed in  Section VII, only minor and
     isolated erosion and sediment  control problems have  resulted from
     extending development  to these areas.  The principle sources of eroded
     sediments are  the larger and frequently  oversteepened cut slopes which
     are required when construction occurs on steeper terrain.  Where possible,
     the excavated  cuts and fills were revegetated by topsoiling, however,
     the steepest slopes were frequently  left unvegetated and  highly erodible.

     An additional  erosion problem  associated with the  construction of condo-
     minium,  homesites,  and commercial buildings is  the undergrounding of
     utilities,  such as water distribution lines,  trunk sewers, and electric
     and cable TV service.   At Northstar  these  operations were usually
     performed conjunctively with construction  of  roadways and building units.
     Occasionslly,  the undergrounding of  utilities necessitated the excavation
     of easements through steeply sloping, previously undisturbed terrain.
     To stabilize these areas satisfactorily, water  bars and erosion checks
     were placed across the disturbed easements to drain runoff to adjacent
                                     72

-------
Figure V-5.  Condominiums at Northstar situated
in an area of minimum environmental impact with
 little disturbance to surrounding vegetation.
Figure V-6.  Discharge of condominium parking
 lot runoff to downslope undisturbed area at
                 Northstar.
                     73

-------
                          TABLE V-2

               DEVELOPED AREAS AND PERCENT OF
                  DEVELOPMENT UNIT TYPE .IN
                   "DEVELOPABLE" AREAS^'—'
   Development
    Unit Type
          1977
        Land Use
  Total
   Area
(hectares)
                                  "Develop-
                                    able"
        ULTIMATE
      Land  Use Plan
  Total           %
   Area      "Develop-
(hectares)	able"
Commercial              9.73

Utilities               5.97

Co ndominiums           19.56

Residential Lots       47.66

       TOTAL           83.92
                38%

                31%

                71%

                82%

                70%
   15.52

    6.52

   79.09

   86.33

  187.46
58%

23%

66%

80%

66%
A/ "DEVELOPABLE" means areas with less than 15% slopes and vegetation
   which can sustain development with "forest management controls".

_B/  AREAS are those areas defined by unit boundaries,  not the areas
    which are covered by just impermeable surfaces.
undisturbed areas.  Along with the replacement of native seed-rich top-
soil, the erosion checks greatly facilitated the rapid reestablishment
of vegetation.

For the most part, extensive erosion control facilities were not required
for the Northstar condominiums, village center, and homesites.   This  is
primarily due to the planning expenditures made in centering these
portions of the development in areas most amenable to construction
activities.  The total cost of the basic improvements for the Northstar
condominium, village center, and homesite units was $4,800,000.   This
included the cost of roadways, parking lots, utilities, and other
"prebuilding" development amenities.  Of this total amount only  $79,584
or 1.66 percent, was spent on special erosion control methods.   Among
these special erosion control methods were the following:

     1.   Check dams and erosion baffles.
     2.   Rock riprap energy dissipators.
     3.   Rock riprap 'V ditches.
     4.   Rock riprap drainage channels.
     5.   Rock riprap slope protection.
     6.   Top soil removal, storage, and replacement.
                                 74

-------
     Not included with these "special" erosion control methods were  the
     cost of what may be considered normal or standard structures such as
     A-C curbs,  dikes and gutters,  drainage culverts, drop  inlets, and
     perforated groundwater collection pipes.   The  total  cost of all the above
     facilities, including special  erosion control,  amounted to $510,866 or
     less than 11 percent of the total "prebuilding" development cost.

D.   Remaining Problems

     In spite of the considerable effort  taken by the Northstar planners and
     developers, certain erosion and sedimentation  related  problems  were
     created by the development.  In most cases these remaining pollution
     sources were identified as  potential problems  during the planning of
     Northstar.   Although recognized in the planning phase, adequate mitiga-
     tion measures were not immediately carried through to  the construction
     and maintenance phases.   As  a  result the  water  quality monitoring pro-
     gram,  described in Section VII of this report,  has documented an esti-
     mated one-fold increase in  the sediment yield  of the West Martis Creek
     watershed.   In addition,  a water quality  computer simulation program was
     used to identify the specific  location and relative contribution of sus-
     pended sediments being discharged by various portions  of the development.

     Five areas  were documented as  the significant areas of erosion  affecting
     the water quality of West Martis Creek.   If these remaining problem
     sources were corrected within  Northstar,  post-development erosion and
     sediment transport levels would be reduced to very low pre-development
     levels in all but the most intense and severe storm runoff events.
     Figure V-7  indicates the  location of  major  remaining sediment and erosion
     problems identified at Northstar.

     1.    Unrevegatated Oversteepened Slopes

          These  remaining problem areas were mainly  centered around the west
         village center parking area,  the wastewater treatment plant,  and
         Northstar Drive.   The main source of  sediments eroded from over-
          steepened slopes  was from the west village parking lot.   Here,
         drainage from the almost  0.75 hectares of disturbed slopes reached
          suspended sediment levels  of  7560 ppm.  The average concentration
          recorded in 19 samples taken during rainstorms and snowmelt runoff
          events  was  1,732  ppm.

         In many cases,  the slopes  adjacent to the west parking lot are 1.5:1
          (horizontal  to vertical) or steeper.  These slopes are generally too
         steep  for the technique of  topsoiling.  No other attempt was made
         to  revegetate these slopes by the Northstar developers.  The
         apparent  reason for these  large, unstable cut slopes  was that  if
  *      they had  been cut at a less severe angle,  they would  have  produced
         longer, more visible scars.  In addition,  there were  no  other
         areas within the  development which were better  suited for  the
         construction of a parking  lot facility necessary for  access to  the
         ski area.  Similar to the  cut slopes for the parking  lot,  Large
         cut slopes were also created by the construction of the  wastewater
                                     75

-------
          Figure V—7.   Rock rip-rapped check dams protecting
           an area at  Northstar disturbed  by the underground
                         placement of  utilities
     treatment plant.   In both cases,  the  cut  slopes intersected semi-
     permeable hardpan layers supporting perched water tables during
     spring snowmelt conditions.   The  hardpan  layers are the remnants of
     buried Pliocene stream beds.

     Northstar Drive exhibited erosion problems similar to, but less
     significant than,  the parking lot and wastewater treatment plant
     cuts.   In this case, no groundwater table was pierced during road
     construction activity, so the problem consists of road sand and
     eroded sediments  from an unvegetated  fill slope carvied by storm
     and snowmelt runoff.  Differences in  suspended solid concentrations
     of up  to 100 ppm have been measured in West Martis Creek from above
     to below the road's crossing  for  the  stream.

2.   Urban  Runoff

     The principal source of measureable urban runoff is from the village
     center commercial area and adjacent condominium units.  To a large
     degree, suspended sediments contained in  urban runoff originates
     from the oversteeped slopes described above.  However, a large
     part is apparently contributed by winter  road sand and dirt trans-
     ported to the parking lot areas by vehicular traffic.  Accumulated
     urban  runoff at Northstar is  discharged to West Martis Creek at
     two major points  near the confluence  of the West and East Forks
                                 76

-------
                        FIGURE V-8.
EROSION  PROBLEMS  IDENTIFIED  AT  NORTHSTAR,  1974-1976.
                            77

-------
of West Martis Creek.  The "village culvert" discharges accumulated
storm and snowmelt runoff from the village center (and most  of the
parking lot area) to the West Fork above the confluence.   A  rock-
lined-drainage ditch discharges accumulated storm runoff from a
portion of the parking lot, condominium units,  and Northstar Drive,
about 100 meters below the confluence.  The maximum recorded
suspended sediment concentration recorded at these two sites were
1,188 ppm and 5,500 ppm for the village culvert and rock-lined-
drainage ditch, respectively.  The average of 50 samples collected
at these two sites during runoff conditions is 394 ppm.

The potential for urban runoff problems to develop at the village
culvert was clearly recognized in the planning process at Northstar.
As part of the environmental impact report prepared prior to the
development of the village center, the following recommendation
was made (11):

     "In order to insure compliance with the State of California's
     Porter-Cologne Water Quality Control Act and Northstar's
     internal quality control standards, it is recommended that an
     adequate catch mechanism and energy dissipator such as
     "bubbleup" catchment basin and sediment pond or other similar
     devices be installed and serviced regularly in order to pro-
     vide for settlement of suspended sediment prior to outfall
     into Martis Creek.  There should be no significant deviation
     beyond natural background levels of turbidity and total sus-
     pended dissolved sediment load.  The construction of a  catch-
     ment mechanism and sedimentation provision as recommended
     above should slow the drainage water to a velocity equal to
     or less than Martis Creek and will minimize the ^cutting and
     carrying power of the water as well as the size of particles
     carried by Martis Creek."

However, there was never any suspended sediment settling or  catch-
ment basin installed as recommended.  Had such a facility been
adequately designed, installed, and maintained, suspended sediment
discharge to West Martis Creek from the "village culvert" would
have been greatly reduced.

The village culvert drainage area possesses two factors that tend
to increase its effect on the stream.  First, the parking lots
drain to drop inlets which transport the flow directly to the
stream through the village culvert.  Second, during the winter
months, a moderate amount of sand and salt used on highways  and
at the entrance to Northstar is tracked to these lots and deposited
by warm dripping cars.  This deposition is not a serious problem
under most winter conditions because the majority of the sediment
is removed from driving surfaces by periodic snow plowing.   However,
during periods of winter thawing, significant levels of salts and
suspended solids appear to be discharged from these surfaces.   This
discharge,  in combination with the erosion from the cuts, appears
to have significant effect on the water quality of the lower
                             78

-------
          Figure V-9.   Oversteepened and eroding  cut  slope
           adjacent to the parking lot  at Northstar in  the
                          spring of 1975
     watershed.   For example,  water sampling  on  February 19, 1975,
     established the village culvert as  the sole source of pollution
     for the West Fork of West Martis.   Its flow of 14 liters per
     second with a concentration of suspended sediments (S. S.) of
     1,072 ppm,  turbidity reaching 330 FTU, and  a concentration of total
     dissolved solids (TDS)  of over 500  ppm adversely affected stream
     water quality to the confluence of  East  and West Forks of Martis
     Creek (S. S. = 1240 ppm;  TDS = 170  ppm).  These conditions to
     persist to  reduced degree for some  distance further downstream.

3.   Unvegetated Ski Run and Uncontrolled  Drainage

     The transport lift area is  located  just  above the village center.
     For the period of May 9 to  22, 1975,  water  containing 3,200 to 6,090
     ppm suspended solids concentration  flowed across this skiing.thorough-
     fare and entered the West Fork of West Martis Creek near the bridge
     to the recreation complex.   The problem  was the result of a drainage
     culvert from a condominium  unit depositing  its flow on an unrevege-
     tated ski run and transport lift area.   This flow created up to
     0.5-meter deep gullies  near its source.   There was also up to 10
     centimeters of sheet erosion on the open slopes and up to 0.25
     meter deep  gullies formed near the  confluence with the West Fork.
     This problem was further compounded by heavy vehicular and ski
     traffic during the spring snowmelt  period which had a tendency to
     further disturb the unrevegetated terrain.
                                 79

-------
4.   Heavily Travelled Dirt Road Drainage

     The only dirt road at Northstar which  receives heavy traffic during
     runoff events is the access road  to  the  ski maintenance area.
     During periods of heavy spring  snowmelt  and runoff, road drainage,
     extremely high in suspended sediments, enters the East Fork of
     West Martis Creek at the point  of road crossing.  The creek crossing
     is located at a low point where the  road slopes down to the creek
     from both directions.  Although streamflow is directed under the
     roadway, drainage from snowmelt collects at the low points and
     enters the creek.  Suspended sediment  concentrations as high as
     4,169 ppm have been detected in the  road drainage.  During spring
     snowmelt conditions, the instream suspended sediment concentration
     of the East Fork has gone from  near  zero to 100 ppm.

     Were it not for the vehicular traffic  during the springtime, this
     dirt road would not pose much of  a problem.  Maintenance vehicles
     and other traffic clearly aggravate  the  situation by disrupting
     the road surface causing the area to become extremely muddy.  The
     ultimate solution would be to pave the road surface to eliminate
     the disruption caused by vehicular traffic.  Also required is
     adequate drainage of storm flow from the road surface to the East
     Fork.  Because of this single suspended  sediment problem source in
     the East Fork the yearly suspended sediment yield of this portion
     of the West Martis watershed was  increased approximately 3 to 4
     times above natural background  levels. -

5.   Uncontrolled Drainage at the Base of the Ski Bowl

     These problems located high in  the watershed at the base of the ski
     area are only noticeable during periods  of extremely high storms or
     snowmelt runoff.  Because of the  design  and layout of the ski bowl,
     erosion problems have been held to a minimum.  Except during high
     runoff conditions, surface runoff is almost completely percolated
     to groundwater.  At the base of the  ski  area, the groundwater is
     tapped by means of a perforated pipe collection system to serve as
     a source of domestic water supply.  With the exception of some
     springs and the water system bypass, very little surface flow
     appears at the base of the ski  area  except during extremely high
     runoff conditions.  At these times,  disturbed areas on unstabilized
     drainage channels do contribute to higher than background levels
     of suspended sediment in the West Fork of West Martis Creek.

Demonstration of Erosion Control Technology

It must be emphasized that, although a few  isolated instances of inade-
quate erosion control exists at Northstar,  the vast majority of the
development is an extremely well planned, designed, and constructed
example of proper erosion control methods and procedures.  In order to
demonstrate additional erosion control technology, the remaining prob-
lem areas at Northstar were selected for  concentrated extra effort.  The
                                 80

-------
demonstration of permanent vegetative erosion control and/or drainage
control facilities was demonstrated on:   (1)  steeply cut slopes
adjacent to the West Village parking lot and  adjacent to the waste-
water treatment plant, (2) cut and fill slopes adjacent to  Northstar
Drive, (3) the unrevegetated and poorly drained ski run near the  base
of the transport lift, and (4) the heavily travelled dirt road adjacent
to the East Fork of West Martis Creek.

Fifty-two different demonstration plots and sections were established  on
the cuts adjacent to the parking lot, the wastewater treatment plant,
Northstar Drive, and the unrevegetated ski run.  A variety  of different
erosion control techniques were demonstrated  at those sites, including:

     1.   Contour willow wattling
     2.   Willow staking
     3.   Native shrub plantings
     4.  _Rock lined drainage ditches
     5.   Rock breast walls
     6.   Slope scaling
     7.   Overhang removal
     8.   Grass seed and fertilizer drilling
     9.   Grass seed hydromulching rates
    10.   Grass hydroseeding rates
    11.   Straw mulching rates
    12.   Various mulch tackifiers
    13.   Various fertilizers at differing rates

A complete description of the individual techniques and procedures of
those measures listed above is included in Section VIII.  Diagrams and
tables listing the various plot and section treatments at Northstar are
included in Appendix B.  Several of the revegetative plantings had to
be reconducted at Northstar in order to establish sufficient growth for
effective erosion control.  Many of the original techniques were unable
to establish viable plant growth.  The hydromulching techniques,  partic-
ularly when an additional tackifier was used, did somewhat  poorer than
straw mulching.  The use of willow wattling vastly increased the success
of any other revegetation technique used with it.  At Northstar,  the
best revegetative growth for purposes of erosion control was achieved
by the following procedure:

     1.   Removal of all overhangs at the crown of the slope and scale
          slope surface of loose material.
     2.   Contour willow wattling placed on slope at 2.0 meter intervals.
     3.   Hydroseeding slope with at least 100 kg/hr seed mixture.
     4.   At least  280 kg/ha 16-20-0 fertilizer applied with hydroseeding.
     5.   Straw mulch blown on slope at a rate of 4500 kg/ha.
      6.   Straw tackifier used at twice manufacturers recommended appli-
          cation rate.

Please refer to Section VIII for an  in-depth description of these and
other revegetation methods.
                                  81

-------
     At Northstar, the installation of a wide variety of different  temporary
     sedimentation control devices were demonstrated adjacent to  the golf
     course construction site.   In the first half of November 1975, the
     following were installed:

          1.   Filter fabric fences
          2.   Impervious berms
          3.   Pervious filter  fabric berms
          4.   Bervious sand core berms

     These devices were installed so as to provide the waters of  West Martis
     Creek with sufficient protection during the construction of  the second
     9 holes of the Northstar golf course.  All the above listed  methods
     performed well but began to show signs of failure after  about  9 months
     exposure to the elements.   In particular, the exposed filter fabric of
     the filter fences began to degrade because of the exposure to  ultra-
     violet radiation in sunlight.  As are the other erosion  control methods,
     the construction of the various temporary siltation control  methods is
     described in detail in Section VIII.

F.   Northstar Cost Summary

     Northstar is basically a well planned,  constructed,  and  maintained
     development north of the Lake Tahoe Basin,  which has minimized potential
     adverse environmental impacts.   The total cost of the residential,
     commercial, and condominium development (not including land  costs) was
     about $28,000,000(14).   The costs of  the additional recreational
     amenities of the development such as  the ski area,  the golf  course, the
     recreation center, and equestrian center,  were an additional $8,000,000.
     By assigning the entire cost of the predevelopment planning  to
     environmental impact mitigation and erosion control,  the following cost
     summary may be made:

          1.   Predevelopment erosion control  $280,000
          2.   Erosion control  construction      80,000
 *i
                                   Total       $360,000

     Thus, the $360,000 spent for the effective erosion control at Northstar
     between 1970 and 1973 represents less than 1.3 percent of the  total
     development cost.

     As of 1977, there was a total of about  930 developed condominiums and
     residential lots at Northstar.   The total cost of erosion control per
     currently developed unit is $390.   The  complete development  plan at
     Northstar calls for a total of  over 2,000  developed condominiums and
     residential lots.  The cost per developed unit (in 1973  dollars) is
     estimated to be reduced to $220 per unit at full development.  As shown
     by this analysis, effective predevelopment planning  as conducted at
     Northstar is an extremely  cost-effective method of  erosion control.
                                      82

-------
                                  SECTION VI

                RUBICON PROPERTIES:   A CLASSIC EXAMPLE OF MASSIVE
        EROSION PROBLEMS DUE TO POOR PLANNING AND CONSTRUCTION PRACTICES
Rubicon Properties is diametrically opposed to Northstar in terms  of  the water
quality protection and the degree of environmental impact.   Northstar's de-
velopers went to significant effort to construct a well planned development;
Rubicon's developers did little planning.   Northstar was constructed  with
minimum environmental impact; Rubicon Properties was constructed with little
environmental awareness.  The developers of Northstar exhibit a desire to
maintain a minimal environmental impact and to correct remaining minor
problems; Rubicon Properties' developers have long since sold all  interest in
the subdivision and cannot be held accountable for the impact Rubicon
Properties is having on water quality and the environment of Lake  Tahoe.

Rubicon Properties is a single-family residential subdivision on the  west
shore of Lake Tahoe, eight kilometers north of Emerald Bay  on State Highway
89.  There are 632 subdivided parcels in this subdivision of which less than
one-half are currently built upon.  Approximately one-third of the 128 hectare
subdivision is within the Lonely Gulch Creek watershed.  The entire Lonely
Gulch Creek watershed, as modified by drainage patterns within the develop-
ment, covers 288 hectares.  The watershed ranges from the mouth of Lonely
Gulch Creek entering Lake Tahoe at an elevation of 1,898 meters to the top of
Rubicon Peak at 2,799 meters.  The highest point within the subdivision is
2,127 meters.  With the exception of the riparian zone adjacent to Lonely  *
Gulch Creek, the watershed is covered with a relatively dense mixed coniferous
forest down to the Lake's shore.

The original land from which Rubicon Properties was subdivided was a  160
hectare parcel held in single ownership.  By 1945, several  land exchanges
and sales had taken place, Rubicon Land Company had been formed, and  the
lower portions of the original parcel were subdivided.   In  1958, 1959, and
1960, the remaining portions of the original parcel,  situated higher  in the
watershed, were also subdivided, resulting in the development we have today.

That portion of Rubicon Properties subdivision specifically chosen for detailed
analyses and implementation of erosion control measures was the uppermost 24.4
hectares within the Lonely Gulch Creek watershed to the west of State Highway
89 (See Figure VI-2).  The soils of this portion of the subdivision are
designated by a recent soil survey (15)  as "Meeks" very stoney, loamy, coarse
sand, with 30 to 60 percent slopes (MsG).   This soil type is representative of
the type of granitic soils found in approximately two-thirds of the Lake Tahoe
Basin.  Erosion hazard is described as being moderate,  in undisturbed areas,
                                      83

-------
                      Figure VI-1.  Rubicon Properties
                 subdivision on the west shore of Lake Tahoe
to high, in disturbed areas.  This is due to a low percolation capacity of the
soi^, leading to rapid runoff.  As a result, the area of the subdivision is
classified by the Tahoe Regional Planning Agency (TRPA) in their lowest land
capability class (16) which allows only a one percent impervious surface
coverage.  Furthermore, TRPA has designated "General Forest" as the
appropriate land use.  However, due to certain "grandfather" clauses in the
TRPA charter, residential construction in Rubicon Properties continues to this
day.

A.   Erosion Problems

     When the erosion control project was first started, the land coverage
     within the area identified for the project site was as follows:
     1.   Impervious coverage
          on private lots

     2.   Impervious county
          road surfaces
1.15 ha.
2.73 ha.
 5%
11%
                                       84

-------
      LEGEND
       PROJECT SITE
       DISTURBED  AREAS
       EXISTING HOUSES
           STATE OF CALIFORNIA
     STATE WATER RESOURCES CONTROL BOARD
        RUBICON  PROPERTIES
            PROJECT  SITE
100     200    300    400
    DEMONSTRATION  OF  EROSION AND
     SEDIMENT  CONTROL TECHNOLOGY
SCALE  (METERS)
85

-------
3.   Disturbed and unvegetated     3.26 ha.        13%
     surfaces

4.   Undisturbed area             17.22 ha.        71%

     Total                        24.36 ha.       100%

Currently, only 19 percent of the lots within the project  site have resi-
dences constructed on them.  With 100 percent build-out  in the future, it
is estimated that the total area of either impervious  surfaces or dis-
turbed, unvegetated slopes would constitute almost 50  percent of that
portion of Rubicon Properties designated as an erosion control project
site.  This is clearly a substantial increase over the "maximum" 1 percent
average identified according to the land capability and  erosion hazard of
the development site.  Not only does land disturbance  associated with
home and road construction lead to higher erosion rates, but concentrated
runoff resulting from impervious roof tops and road surfaces further
increases the problem.  The harm caused by concentrated  runoff was
unintentionally demonstrated by one homeowner who kept a small flow of
water (less than % liter per minute) trickling through an  outside spigot
during the winter of 1976 to prevent pipes from freezing.   This very
small concentrated flow resulted in a one meter deep and one meter- wide
eroded swail in his front yard the following-spring.
              Figure VI-3.  Deposition of granitic sediments
               in Lonely Gulch Creek resulting from erosion
                  within Rubicon Properties subdivision
                                 86

-------
 The majority of  the 3.26 hectares of disturbed, unvegetated slopes have
 not supported any vegetation for the entire 18 years since they were
 first  excavated.  Embankments which were originally cut with 1:1 or
 greater  slopes have eroded to 1%:1 slopes or less.  Even the exposed
 granitic layers  have probably weathered away at an average rate of 2 to 5
 centimeters per  year.  In most cases, the eroded or weathered material
 was continually  deposited in asphalt concrete drainage/troughs at the
 slope  toe adjacent to the paved roadways which zigzag up the hillside.
 The deposited material remained in these troughs only until the next
 rainstorm or heavy snowmelt at which time it was rapidly transported down
 slope  through an interconnected system of impervious ditches, culverts,
 swails, 'and troughs until it was discharged to Lonely Gulch Creek and,
 subsequently, to Lake Tahoe.

 Longtime residents of the area have indicated that fishing Lonely Gulch
 Creek  was a common occurance prior to construction of the development;
 (the creek apparently sustained a healthy trout population).  Prior to
 the early 1930's, development consisted of 1 residential estate which
 tapped Lonely Gulch Creek for hydroelectric power generation and inci-
 dental domestic water supply.  Since the upper portions of the develop-
 ment were added  in the late 1950's, it is extremely unlikely that any
 trout  could survive in that portion of the stream affected by runoff from
 the subdivision.  Indeed, as discussed in Section VII,  benthic
 macroinvertibrate populations monitored between 1972 and 1976 have shown
 up  to  a  99 percent reduction in aquatic life in affected downstream
 portions.

 Clearly,  the upper portion of Rubicon Properties subdivision has been
 the site of massive erosion since it was constructed in 1959.   Through
 discussions with local residents, the State Board staff has been able to
 estimate the original configuration of the unstable cut and fill slopes.
 By  comparing their estimates of prior conditions with current slope con-
 figuration, the amount of material eroded from the erosion project site
 since  1959 was estimated to be 6,255 cubic meters or 8,660 metric tons.
 Thus,  an average of 1,975 metric tons per square kilometer per year are
 estimated to have eroded from the project site between  1959 and 1976..
 As  discussed in Section VII,  the current sediment discharge from the
 project .site was estimated to be 366 metric tons per square kilometer
 per year for 1975 to 76.   Based upon this analysis,  it  must be assumed
 that considerably more sediment was eroded from the upper portions of
 Rubicon Properties immediately after construction than  is currently being
 eroded.  This is quite reasonable in view of the fact that over a period
 of  18 years the original slopes within the development  had been eroded to
 less severe slope angles,  more nearly approaching the angle of repose
 of  the soil.   This action has led to the gradual "natural" stabilization
 of  some slopes during the period from 1959 to  1976.   Assuming  a straight
 line curve between 1959  and 1976,  Table VI-1 depicts  the estimated
 erosion rate for each year of this period.

Although predevelopment water quality and hydrologic  monitoring was
nonexistent,  water quality of the undisturbed  2J5 hectares  of  Lonely
Gulch watershed above Rubicon Properties is  assumed  to be representative

                                 87

-------
    of predevelopment conditions for the entire watershed.   The upper por-
    tions of the watershed have not been significantly disturbed,  since logging
    operations were last conducted over 100 years ago.  Based upon the water
    quality monitoring program described in Section VII, the natural background
    level of erosion for the upper, undisturbed portions of Lonely Gulch Creek
    watershed is 3.43 metric tons per square kilometer per year.  The geolo-
    gic  configuration and soil type found in the upper portions of the sub-
    divisions are slightly different from the upper watershed.  Nonetheless,
    it has been assumed that the natural background rate of 3.43 metric tons
    per  square kilometer per year is a reasonable assumption for all undis-
    turbed portions of the watershed.  Thus, the monitored average erosion
    rate of 366 metric tons per square kilometer per year for the period of
    1973 to 76 is a 10,600 percent increase above assumed natural background
    levels.  Even more astounding is the possibility that the initial erosion
    rate after the construction of Rubicon Properties, as depicted in Table
    VI-1, may have been as high as 3,669 metric tons per square kilometer per
    year - over a 100,000 percent increase above assumed natural background
    levels.

    From the standpoint of erosion control, the upper portion of the Rubicon
    Properties subdivision is clearly representative of a poorly planned,
    designed, and constructed development.  Had the county with jurisdiction
    properly exercised the constraints which were embodied in their own
    subdivision ordinance in 1959, the upper portions of Rubicon Properties
    might never have been constructed.  The county subdivision ordinance
    in effect in 1959 required that the county road right-of-way must include
    all road cuts and fills associated with road construction (17).  Currently
    about  90 percent of the disturbed slopes within Rubicon Properties lie
    outside the county maintained road right-of-way.  Had the ordinance been
    enforced, there would have been over 14 percent less developable land
    available for subdivided residential lots.  This may very well have
    discouraged the developer from the standpoint of anticipated revenue.
    Even if the development had still been constructed, adherence to the
    subdivision ordinance would have left the majority  of the most severe
    erosion problems under single ownership, which would have greatly facili-
     tated  problem correction.

    The poor planning and construction of the upper portions of Rubicon
    Properties goes beyond generating excessive erosion and sedimentation
    problems.  Improper or inadequate roadway construction, domestic water
     supplies, storm water drainage facilities, sewage treatment facilities,
    and lowered aesthetic appeal are also embodied in Rubicon Properties
     subdivision.

B.  Roadway Construction Problems

     The roadways within the upper subdivision pose a maintenance problem
     for the county, and will  continue to be a problem even with erosion and
     sediment under  control.   Several roads have grades  in excess of 15 percent.
     Once again,  the county subdivision ordinance, which allowed a maximum
     grade of 12.5 percent  in  1959  (17), was ignored by  the developer and  not
     enforced by  the county.   Even 12.5 percent is very  steep as compared  to
                                      88

-------
   Figure VI-4,  Steep roadways and oversteepened cut and fill slopes
        within Rubicon Properties subdivision, Lake Tahoe Basin
                            TABLE VI-1
                  ESTIMATED YEARLY EROSION RATES
                   FROM THE UPPER 24.4 HECTARES
                    OF RUBICON PROPERTIES FROM
                        1959 THROUGH 1976
               Erosion Rate
                                                  Erosion Rate
Year
1959
1960
1961
1962
1963
1964
1965
1966
1967
(Metric Tons/ha/yr)
36.20
34.10
32.00
29.90
27.80
25.70
23.60
21.50
19.40
Year
1968
1969
1970
1971
1972
1973
1974
1975
1976
(Metric Tons/ha/yr)
17.30
15.20
13.10
11.00
8.90
3.66
3.66
3.66
3.66






4-Year
Average

Natural background erosion rate monitored from undisturbed
watershed =  .0343 metric tons per hectare per year  (1973, 1975-76)
                                 89

-------
     current standards.  The maximum road grade currently considered practical
     for access in mountainous regions is 6 percent.  The primary reason^for
     this  is the difficulty of removing snow on steeper roadways. In addition,
     ice formation on steeper grade makes access extremely difficult for
     standard  automobiles and poses a severe traffic hazard.  As the upper
     portions  become developed further, it is anticipated that the level of
     winter road traffic will continue to increase, further increasing the
     road  hazard.

     Snow  removal equipment has an extremely difficult time within the upper
     portions  of Rubicon Properties, particularly in very severe winters.
     The large vehicles have problems negotiating the extreme switchback
     turns which exist in the subdivision and frequently cannot gain traction
     on the steep road surfaces.  Furthermore, the  close proximity of the
     steep road cuts  to the road  surface severely limits the amount of snow
     storage area.  As a result,  the snow removal equipment invariably operates
     too close to the fill side of the roadway, rupturing curbs, dikes, and
     gutters.   These breaches in  the roadside structures cause further overland
     discharge and  erosion problems.

C.   Storm Water Drainage Problems

     Because of the extremely steep  terrain and high percentage of disturbed
     land  and impervious surfaces (29 percent), adequate drainage control in
     the upper portions of Rubicon Properties is extremely difficult.
     Drainage ditches,  curbs, and gutters, culverts, and sectional downdrains
     used within  the development  are generally undersized for the extreme
     flows which occur  during high runoff  events.   The adequacy of these
     facilities is  further decreased by  constant clogging with eroded soil
     from the disturbed terrain.  Prior  to the erosion control project,
     substantial areas  within  the development did not even have dikes to
     prevent road surface  runoff  from flowing over  adjacent fill slopes.  One
     slope, a 0.4 hectare  fill  area, lost  at least  1.0 meter of  soil, averaged
     over the entire slope face,  due to  the absence of dikes.  The drainage
     ditches used to convey snowmelt or  storm  runoff are all unstable, unlined
     eroded swails.  In many instances,  flow from  corrugated metal pipe  culverts
     was allowed to spill over unstable  steep  soil  surfaces prior to discharge
     to the Lonely Gulch Creek.   The result has been the appearance of several
     deeply eroded artificial swails.

     While  the current level of development has  created substantial areas of
     disturbed or impervious surfaces,  it is nothing like  the  level which
     would be reached upon full development  of  the  subdivision.  The existing
     drainage facilities are inadequate for  the  current level  of development
     (16 percent impervious surfaces).   With full  development  (37 percent
     impervious surfaces),  drainage problems will  be considerably magnified.
     Without substantial revamping of  the drainage facilities  and complete
     erosion control, Rubicon Properties will not  be able  to bear the load  of
     full development without major failures  of  the existing drainage system.
                                      90

-------
D.   Maintenance Procedure Problems

     Numerous improper or questionable maintenance practices have been observed
     to be conducted within Rubicon Properties  subdivision by  the various local
     maintenance and utility agencies.   These practices  generally increase the
     rate and/or the amount of erosion which-would otherwise occur within the
     subdivision.  The most visible of improper maintenance practices is the
     application of sand to road surfaces  in the winter  time without adequate
    . provisions for cleanup and removal of applied sand.  Depending on the
     severity of the winter,  anywhere from 10 to 40 metric tons of road sand
     are applied to 2.5 kilometers  of roadways  within  the Rubicon Properties
     project site annually.  This applied  road  sand may  account for 5 to 25
     percent of the suspended sediment load which  has  been monitored in Lonely
     Gulch Creek.  In most years, only token attempt is  made to cleanup and
     remove applied road sand.   This is generally  performed by a mechanized
     roller broom.   This technique  removes the  road sand from  the street
   1  surface (only to be redeposited in roadside ditches or downslope areas)
     and does little to reduce the  amount  of road  sand which is eventually
     washed into Lonely Gulch Creek and Lake Tahoe.  A more appropriate
     procedure would employ vacuum  type brooms  for the removal and proper
     disposal or reuse of the waste road sand.  In addition sediment catchment
     basins or drop inlet structures should be  provided  to collect any
     remaining waste road sand which could be washed from the road surface.

     Other maintenance practices also increase  the rate  and/or amount of
     sediment yield from the  Rubicon Properties project  site, or otherwise
     increase the severity of the development's erosion  problems.  Among
     them are:

     1.    The practice of removing  accumulated  sediments from the toe of an
          eroding slope which undercuts the stability  of the slope and leads
          to an increased erosion rate.  Better practice would be to move
          existing  drainage further away from the  toe  of an eroding slope,  or
          construct a retaining structure.

     2.    Washing culverts and  drains  clogged by eroded sediments increases
          the rate  of downslope sediment transport.  Better practice would
          include the dry boring or reaming of  the culverts to remove
          sediments coupled with the  proper disposal of  the waste earthen
          materials.                 >

     3.    Insufficient snow stakes  can  result in increased damage to curbs,
          dikes,  gutters,  retaining  structures, and slope toe benches by
          snow removal equipment.

     4.    Improper  disposal of  waste earthen material,  such as "over-the-bank"
          practices,  increases  sediment  transport and hinders the proper
          establishment  of  slope  stabilization measures.   Better practice would
          include the disposal  of the waste earthen material to a land fill or
          the washing and  reuse  of  the material as winter road sand.
                                     91

-------
     5.   Negligence in providing revegetation or other  stabilization  to areas
          disturbed for the connection of sewer and water  laterals  or  other
          underground utilities.   Frequently,  the disturbed surface acts as  a
          channel for upslope storm runoff or  snowmelt runoff.   Better practice
          would include immediate restabilization using  vegetation, mulch, nets,
          blankets, waterbars, check dams, or  other devices.

     In most instances it appears that these improper practices  are conducted
     as a result of ignorance on the part of the maintenance workers,  the  lack
     of proper equipment to perform the task,  and the intransigence of manage-
     ment to provide the proper incentives.

E.   Other Problems

     In addition to development problems which increase  erosion  rates, there
     are also a number of other problems within Rubicon  Properties  subdivision.
     These additional problems also substantiate the  considerable lack of
     planning and environmental awareness which preceded construction  of  this
     development.

                          1. Domestic Water Supply

     The sole source of domestic water supply is a small storage and diversion
     facility on Lonely Gulch Creek.  The original diversion, initiated in
     the early 1920's, was for hydroelectric power generation and the
     incidental domestic use of one estate.  Since that  time, the manner,
     location, and duration of the water use of water diverted from Lonely
     Gulch Creek has changed—all in probable violation  of California water
     rights law.  Currently diverted water is used to supply approximately
     300 households solely for domestic supply, some  of  which are not  even
     located on the original parcel.  Furthermore, the original seasonal use
     (May-September) has been extended to year round  use.

     The foregoing, however, is not as severe as the fact that there simply
     is not sufficient streamflow in Lonely Gulch Creek  to provide  a safe
     supply for the subdivision.  Although the subdivision is less  than 50
     percent built-out, streamflow is frequently reduced to zero as a result
     of the diversions for domestic supply.  In 1976, a  very dry year, there
     were 25 twenty-four hour periods when streamflow was zero.   Even in
     1973, an average water year, there were periods  of  several days when
     streamflow was zero.  Had the most recent upper  portions of the
     subdivision not been added on in the late 1950's, there would be
     sufficient streamflow in the creek to provide for the complete build-out
     of the original subdivided parcels.  However, even if this were the
     case, streamflow in Lonely Gulch Creek would frequently be reduced to
     zero.  This would still have caused significant damage to the aquatic
     life and riparian vegetation of Lonely Gulch Creek.

     At the present, development of additional sources of water supply are
     somewhat dubious due to  current uncertainty of water rights and water
     availability within the  Tahoe Basin as a whole  (18, 19).  Clearly, the
                                       92

-------
developers of Rubicon Properties subdivision,  and the local  agencies,
and the utilities did not consider the long-term water supply  problem
which would be encountered upon complete build-out of the development.

                       2.  Sewage Treatment

Prior to 1973, domestic sewage waste within Rubicon Properties was
treated individually by septic tank and leachfield systems.  However,
very few homes were existing in the upper portions of the development
where the thinnest soils are found/  For this reason, potential health
problems did not appear.  At full build-out, the upper portions of
Rubicon Properties subdivision would have been unable to support septic
tanks and leachfield systems sufficient to serve over 100 single family
residences located on less than 25 hectares of land.  The possibility  of
health problems would have been increased further by the large cuts and
fills adjacent to the roadways.  Domestic sewage disposed in leachfields
would certainly have resurfaced at several locations within the
subdivision.  Springtime snowmelt seepage areas and very small perenial
springs are manifest throughout the area, particularly on road cuts.
The installation of a regional sewage collection system in 1973 ended
the threat to public health resulting from further expansion and use of
septic tanks and leachfields.  However, the undergrounding of the
collection system substantially increased the .sediment yield and erosion
rate during construction.  This occurrence, again, emphasized the
extreme fragility of the area and the adverse impacts imposed by
conventional construction practices.

Potential sewage treatment problems have not been eliminated with the
addition of a sewage collection system.  Providing adequate sewage
treatment and disposal  facilities is a problem currently facing not only
Rubicon Properties but  most of  the Lake Tahoe Basin.  Rubicon Properties
subdivision receives sewer service from the Tahoe City Public Utility
District  (TCPUD).  The  TCPUD is a member of Tahoe-Truckee Sanitation
Agency  (TTSA), the regional entity designated to treat and dispose of
wastewater from  the north and west shores of Lake Tahoe and the Truckee
River area downstream to Truckee.  Wastewater treatment and disposal
facilities are presently under  construction by this agency.

In a June 19, 1975, action, the State Water Resources Control Board set
maximum seven-day average flow  limitations for all  districts, including
TCPUD,  that are  served  by TTSA.  This will effectively limit the number
of additional sewer connections allowed in individual districts, which
in turn will  limit the  number of existing unimproved subdivided lots
which can be built upon.  An estimate of remaining  available connections
for TCPUD and North Tahoe Public Utility District  (NTPUD) is set at
1,258 single  family dwelling unit equivalents.   In  the TCPUD and NTPUD
combined,  there  exist 6,200 undeveloped lots.

A treatment plant expansion could occur; however, no design, financing,
or environmental documents have been prepared for such a project.  As
with  other  aspects of Rubicon Properties subdivision,  the developers,
 local regulating agencies, and  utilities gave little  considerations to
                                 93

-------
     the sewage treatment problems which would surely occur with the
     development of  the upper portions of the subdivision.

                              3.  Aesthetics

     One visit to Rubicon Properties gives a clear indication as to why it
     was developed in the first place.  The location of the subdivision
     affords the resident and visitor a spectacular view of the Lake Tahoe
     Basin.   No doubt this  fact was on the developers' mind when judging the
     marketability of the development even before the first bulldozer swath
     was cut.  Because of its location on steep  terrain, a "staircase" effect
     is created by the road switchbacks.  Each successive level of resi-
     dential lots allows a  clear view of the Tahoe Basin over the roof of the
     downslope neighbor.

     While the location of  Rubicon Properties offers a spectacular view from
     the development, the series of switchback scars are readily visible from
     many parts of the Tahoe Basin; a highly visible testimony to man's impact
     on the Lake Tahoe Basin.

F.   Demonstration of Erosion Control Technology

     The upper portion of Rubicon Properties subdivision is a unique and
     classic example of all around poor planning and construction practices.
     Seldom is it possible  to find such extensive erosion, drainage, water
     supply, sewage  treatment,  road maintenance, and aesthetic problems all
     concentrated in a single subdivision.  However, from the standpoint of
     demonstrating erosion  control technology, it is a concentrated repre-
     sentative sample of  the most severe  types of erosion problems.  These
     problems are found  throughout the Lake Tahoe Basin and other rapidly
     developing mountainous regions  of California.  Large cut and fill slopes,
     steep cut and fill  slopes,  small  cut  and fill  slopes, abandoned dirt
     roads, heavily  traveled dirt roads,  clear cut  vacant lots, and various
     examples of concentrated drainage problems  are all found within the
     upper portion of Rubicon Properties  subdivision.

     Rubicon Properties  also offers  an excellent site  for demonstration of
     erosion and sediment control  technology because the  impact of uncon-
     trolled erosion and sedimentation has been  well documented within Lonely
     Gulch Creek.  Section  VII  describes  in detail  the monitoring program
     which was conducted in the Lonely Gulch Creek  watershed  to document the
     water quality impact of development  there.  Because  of the successive
     switchback layers of the subdivision,  the  impact  of  the most severe
     erosion problems found within  the  subdivision  are concentrated within
     the Lonely Gulch Creek watershed.

     In June 1975, the staff of the  State Board  in  agreement with the staff of
     the Regional Board,  selected portions of Rubicon  Properties as a project
     site to supplement the effort  already being conducted at Northstar.
     The project site was identified as  the area shown in Figure VI-2.  By
     working from the highest to the lowest points  within the project site,
     within  the time  (July 1974 through  July  1977)  and funding  constraints
                                      94

-------
 of the program,  it was  felt  that  the most severely eroded sediment
 discharges to  Lonely Gulch Creek  could be progressively corrected.

 The first major  obstacle which was  encountered involved obtaining per-
 mission to gain  access  to eroding property from every effected landowner
 within the project site.  A  high  level of response and support was
 gained from the  respective landowners, but much staff time, including
 legal staff support, was required to gain the required permission.  By
 the time the necessary  license agreements were fully executed in the
 fall of 1975,  very little time remained  for construction of erosion
 control facilities prior to  winter  snowfall.  When erosion control
 problems within  a development are the responsibility of a single owner
 similar to the Northstar development, the logistics of effective erosion
 control are greatly facilitated.

 During the summer and fall of 1976  and spring of 1977, a wide variety of
 erosion control  techniques were demonstrated at Rubicon Properties.
 Ninety percent of all disturbed areas, including the most severe, were
 treated.  Demonstrated  erosion control techniques included the following:

 1.   Rock and  gabion breast  wall
 2.   Gabion retaining walls
 3.   Relocation  of curbs, dikes and gutters
 4.   Overhang  removal
 5.   Slope scaling                                            '
 6.   Contour willow wattling
 7.   Willow, staking
 8.   Various seed mixtures
 9.   A variety of hydromulching application rates
10.   Straw mulching
11.   A variety of straw mulch tackifiers
12.   A variety of mulch nets and  blankets
13.   Rock lined  channels

 Complete detailed description of  these and other erosion control techni-
 ques are included in Section VIII.  Appendix B describes the location
 of the various methods  demonstrated within Rubicon Properties.  A total
 of 117 herbaceous seeding "plots" and 20 "sections" containing shrub and
 tree plantings are located within the Rubicon Properties project site.
 The total land area treated  amounts to approximately 2.9 hectares of
 eroding cuts,  fills, slopes  and other eroding, unvegetated problem sites.

 Little was done  to correct the extreme drainage problems which accompany
 and exacerbate the erosion and sedimentation problems.  Drainage control
 within Rubicon Properties would be  an extremely expensive proposition
 and would have required about 50  percent more funds than were available.
 Project funds  were used to correct  drainage problems most directly related
 to, or causing,  erosion problems.  Construction of curbs, dikes, gutters,
 and retaining  walls, for example, enhance drainage control while at the
 same time correcting erosion problems.   The cost of drainage structures
 should not be  assigned  solely to  erosion control; part should also be
 assigned to drainage and flood control.
                                  95

-------
     Figure VI-5.   Eroded and accumulated sediments  at  toe
of oversteepened cut slope within Rubicon Properties subdivision,
         Lake Tahoe Basin, during the summer of  1975
        Figure-VI-6.   Oversteepened cut slope after
     application of mechanical and revegetative  erosion
            control techniques with an estimated
          80-90% effectiveness in reducing erosion
           rates.  Picture taken in the summer of
                            1977
                             96

-------
     Cost Effectiveness      , .:.-.'...-"' ••••:":•         --•  •      ,~

     A qualitative evaluation of the erosion project at Rubicon Properties
     has been made.   According to county personnel,  1977 is the first year
     in memory when massive cleanup  efforts were  not required following
     snowmelt and rainstorms.  Admittedly,  1977 has  been a very dry year with
     little snow.  However, near normal precipitation conditions were recorded
     in May 1977.  No substantial cleanup operations were required during
     this month.   Prior to installation of  erosion control measures at Rubicon
     Properties,  the county would typically spend approximately $11,500 per
     year for county personnel and equipment (230 hours of a two-person crew
     per year plus equipment) to unclog culverts  and cleanup erosion problems
     within the project site.  The total cost to  the county of El Dorado and
     the State of California to install the extensive erosion control measures
     within the project site are listed in Table  VI-2.   The actual total unit
     cost of the  erosion control project at Rubicon  Properties, including the
     assumed value of other contribution of labor, equipment, and material,
     is estimated to be $41,621 per  hectare.  The unit cost to perform an
     equivalent project on a commercial basis, based on individual unit
     cost estimates provided in Section VIII would be over $76,000 per hectare.
     Thus, if the0 following assumptions are valid:

     1.   Negligible erosion and sediment control maintenance would be required
          after a project similar to the one conducted at Rubicon Properties.

     2.   The long-term increased maintenance cost rate is 6 percent (based
          upon the 27 year Engineering  News Record construction cost index
          average since 1950) .
3.
          Money may be borrowed by the county at 8 percent interest.
     Then, the cost of erosion control,  such as that conducted at Rubicon
     Properties, would be amortized over a 12.5 year period.   This analysis
     also assumes all erosion control construction costs are  charged against
     the county maintenance budget only.   This means that none of the erosion
     control costs are assigned to environmental protection,  enhancement,  or
     to other entities besides the county.  Thus, erosion control is clearly
     feasible, particularly if support is provided from sources other than
     from just the directly benefiting and/or directly responsible entity.

H.   Recommended Control Measures

     Based upon an early assessment of the effectiveness of the methods
     employed at Rubicon Properties, it is possible to make preliminary con-
     clusions regarding effectiveness and cost of specific erosion control
     techniques.  For a more detailed discussion of erosion control methods
     and their effectiveness refer to Section VIII.

     General recommendations on individual erosion control methods are ex-
     tremely difficult to make.  Application of each method is highly site
     specific.  Different erosion control methods may be best applied,  either
     singly or in combination, to different sites depending on conditions.

                                      97

-------
There is no one "best" method to control all erosion problems.  At  a
minimum, the following are the major criteria which must  be evaluated
prior to selection of particular erosion control methods:

1.   Soil (or subsoil) type, particle size and nutrient content
2.   Slope length
3.   Slope angle
4.   Drainage patterns
5.   Climatdc conditions
6.   Soil moisture
7.   Exposure and aspect
8.   Surrounding vegetation types
9.   Underlying geology and location of seepage areas

If any one of the above criteria changes from one site to the next,
recommended erosion control methods for a specific site may require
substantial alteration.  All erosion control techniques demonstrated
at the Rubion Properties project site achieved some degree of initial
success.  It is too early to determine a significant difference between
techniques or combinations of techniques, particularly as to their  long-
term effectiveness.  The best yard stick available to measure success
at this early date is simply the treatment cost.

The establishment of vegetation using seed and small amounts of fertilizer,
followed by a straw mulching and tacking process is generally the least
costly method.  However, on steep, rocky terrain, even several seeding
and straw mulching-tacking operations may not be successful.  In  such
cases, the use of mulch nets and blankets, although frequently five
times as expensive, may be the only technique which can successfully
revegetate such a severe site.  Similarly, the use of willow wattling,
though extremely expensive, vastly increases the chances of establishing
vegetation on difficult sites.  The following control methods appear  to
be the best techniques for successfully controlling erosion problems  such
as those found within Rubicon Properties.  At other locations however,
other methods may achieve a higher degree of success depending on the
prevailing site conditions.  Section, VIII of this report offers a more
detailed discussion of all erosion control construction techniques
demonstrated at Rubicon Properties.

1.   Slope Preparation

     Slope preparation is frequently the most important step in controlling
     erosion.  This includes the diversion of drainage waters away from
     unstable slope areas, removal of loose rock and debris, and  the
     removal of overhangs from the top of an eroding slope.  The  top
     portion of an eroding slope should never be steeper than the lower
     portions.  If possible, the entire slope should be laid back to  the
     angle of internal friction  (angle of repose) of the soils found  at
     the site.  If this is not possible the use of extensive mechanical
     stablization, such as revetments or willow wattling, will be
     required.

-------
                            TABLE VI-2

                 EROSION CONTROL COSTS AT RUBICON
                     PROPERTIES PROJECT SITE
DIRECT EXPENSES

     County Road Crews and Equipment
     Special Equipment Rental
     Gabions and Rock Fill
     Unskilled Youth Labor
     20,000 Rooted Plants
     Miscellaneous Materials & Equipment
                                        Subtotal
 $51,000
  17,000
  23,000
  23,000
  15,000
   5,000

$113,000
CONTRIBUTIONS OF OTHERS

     (Equipment) Soil Conservation Service
     (Labor) Forest Service & Homeowners
                                        Subtotal
                                        TOTAL
   2,000
   3,000
$  7,000

$120,000
Total Land Area Treated =2.90 Hectares
Average Unit Cost = $41,621 per Hectare
Estimated Equivalent Commercial Cost = $76,849  per Hectare
2.   Contour Willow Wattling

     Contour willow wattling is  an extremely  effective method of con-
     trolling erosion on excessively steep  and  lengthy slopes (both cut
     and fill).   However,  care must be  taken  in the  installation of this
     method.  The best time for  installation  is in the early spring or
     late fall.   Summer planting is discouraged because of the high
     transpiration losses  suffered by a fully leafed willow branch prior
     to the growth of a new root system.  Without willow wattling, the
     establishment of vegetation on sandy-type  soils with slope angles
     greater than 2:1 is next  to impossible.  Even if contour willow
     wattling does not root and  grow, it provides flexible mechanical
     stabilization which then  enables other vegetation to take root and
     grow.
                                99

-------
3.   Straw Mulching

     Almost all planting techniques demonstrated at Rubicon Properties
     have high degrees of initial plant growth and survival.  However,
     drought tolerant herbaceous seeding, followed by straw mulching  and
     tackifying appears to be the most cost-effective all around
     treatment for many sites.  Generally, a complete straw mulching
     treatment may be applied on a commercial basis at rates ranging  from
     $3 000 to $3,500 per hectare.  This makes it one of the most
     inexpensive techniques demonstrated.  A "tacked straw" treatment
     provides a flexible, strong, light reflective, moisture retentive
     matrix, and ample protection for seed germination and plant growth.
     Superior stands of grass and shrub seedlings have been observed  on,
     most plots which received a straw mulch treatment.  However, in  the
     case of a straw mulching treatment, as with all other  seeding
     techniques, provisions should be made for reapplication of seed,
     fertilizer, straw, and tackifier if the first application is not
     successful due to adverse climatic conditions.

 4.   Slope Toe Foundations

     Adequate slope toe  foundations are  essential  to provide stability to
     an eroding slope.  At Rubicon Properties,  0.9 meter to 2.7 meters
     high  retaining walls were used to provide  adequate  slope toe
     protection.   These were  generally used where  existing  paved street
     surfaces were equal to,  or  less  than, their minimum allowed width.
     El Dorado County ordinances require that paved  road surfaces must be
     maintained at a  certain percentage  of  the  available right-of-way.
     Within Rubicon Properties,  the required paved road  width was
      generally 7.9 meters.   In  areas  where  sufficient  paved road surface
     was present,  existing  curbs,  dikes,  and  gutters were  removed and
      replaced further into  the  right-of-way at  a  greater distance from
      the slope toe.   This eliminated  the need  to  construct large walls to
      provide adequate slope-toe protection.  Reconstruction of  the curb,
      dike and gutter system could be  performed  at costs ranging from 10
      to 25 percent of the cost  of breast walls  or retaining walls.   Had  a
      minimum paved road surface not been required at Rubicon Properties,
      relocation of existing curbs,  dikes, and gutters  could have been
      universally applied as the means of providing adequate slope-toe
      stabilization.   This would have reduced the unit cost of erosion
      control within Rubicon Properties from over $41,000 per hectare to
      less than $26,000 per hectare.  This represents a cost savings  of
      over 35 percent.
                                  100

-------
                                  SECTION VII

                  THE IMPACT OF DEVELOPMENT ON WATER QUALITY
A.   INTRODUCTION

     As part of the Erosion Control Demonstration Project  the  State Water
     Resources Control Board (State Board)  has conducted an extensive
     monitoring program at the two project  sites.   The emphasis  of  the program
     has been placed upon determining to what degree  suspended sediment  is
     generated by the Northstar and Rubicon Properties developments.  In
     addition, the degree to which the respective streams  are  affected by
     erosion has been thoroughly documented by this study,   Water quality
     monitoring programs have been conducted at both  Northstar and  Rubicon
     Properties.  The following parameters  were monitored  as part of this
     Erosion Control Demonstration Project:

               Streamflow
               Suspended sediment concentration
               Precipitation
               Benthic macroinvertebrates
               Snow depth and snowmelt (Northstar only).

     The purposes of the monitoring program were threefold:  (1) to determine
     the location and extent pf any high sediment yield from within the
     respective developments, (2)  to establish,  if possible, a measurement of
     the total sediment mass emission from  each development and  from various
     portions of each development, (3)  to make a comparison, if  possible, of
     post-development sediment yield with estimated predevelopment  conditions.
     A digital computer and a water quality modeling  program were used to
     handle the extensive amount of streamflow and suspended sediment data.
     The program also allowed the State Board staff to estimate  the total
     suspended sediment mass emission for both predevelopment  and postdevelop-
     ment conditions at Northstar and Rubicon Properties.   The formulation and
     operation of the water quality model is described in.a  subsequent part
     of this section.

B.   WATER QUALITY MONITORING PROGRAM

     The following methods and procedures were used to monitor and  collect
     data pertaining to erosion and sediment yield from the Northstar and
     Rubicon Properties developments.
                                      101

-------
Streamflcw

Stevens Type F water stage recorders  positioned in stilling basins
directly upstream from sharp-crested  weirs were used  to provide
continuous streamflow data.   The recorders were manually  reset on a
weekly basis.  Continuous streamflow  recordings were  then digitized in
terms of stage height versus time using a Bendix Data Grid Digitizer and
stored on magnetic computer tape.

Suspended Sediment Samples

Suspended sediment field and laboratory procedures were those established
by Burgy and Knight for use by the State Board for the assessment of silt
and sediment pollution problems (20).   Samples  were collected  using an
integrated suspended sediment hand sampler  designed by Robert H. Burgy.
Samples were collected upstream and downstream of areas of man-made land
disturbance where possible.   Direct discharges of suspended sediment into
streams were also collected by grab sampling.

Suspended sediment was analyzed using the Total Suspended Matter  (Non-
filterable Residue) method as described by  the U.S.G.S.(21).  The water
sample is filtered through a predried, tared 2.1 centimeter glass fiber
filter (Reeve Angel, Grade 934AH) in a Gooch crucible. The filter and the
crucible are then dried at 103 degrees centigrade and cooled  in a
desiccator to room temperature.  The samples are then weighed and the
results are reported as parts per million suspended sediment.

Benthic Macroinvertebrates

Benthic macroinvertebrate communities, mostly aquatic insects which
inhabit the stream bottom in their immature stages, were  sampled  in
several areas near Northstar and Rubicon Properties,  above and below
zones of land disturbance.  Similar investigations in other areas have
shown that the structure and population of macrobenthic  communities were
adversely affected below areas where sediment has been discharged into
streams.  This relationship suggests that benthic macroinvertebrate data
may be used  to indicate that excessive sedimentation has  occurred in
suspected areas.  In addition, it offers an assessment of the direct
impact that  silt has on aquatic biota.

Surber sampling of a one square foot section of stream bottom for each
sample was the method of collection employed for benthic macroinverte-
brates(22).  Due to the rocky substrate of the stream bed and the shallow
depth of the streams, it was decided that Surber sampling would be  the
most efficient and effective collection technique.  Using the Surber
square foot  sampler, Needam and Usinger(23) determined that the 194
samples were required for an estimation of total wet weight,  and 73
samples were needed for an estimation of total numbers of bottom
organisms to attain significant  figures a.t the 95 percent level of
confidence.  However, only two or three samples were needed,  at the
                                  102

-------
 95 percent level of confidence, to insure that at least one member of
 each of the commonest genera of bottom organisms would be present.

 Allen(24) and Davis(25) discovered that when samples are taken at places
 selected by the eye to be as environmentally similar as possible, there
 is a smaller range of variation between samples.  In gridded or
 randomized series sampling, the coefficient of variation in Allen's
 sampling was between 0.4 and 0.5.  In sampling uniform areas, the
 coefficient of variation was about 0.2.

 In this study, an attempt was made to sample riffle areas of the same
 depth, velocity, and substrate type.   Stations, where three to four
 samples were taken, were located above and below areas of man-made land
 disturbance and sediment discharges according to the recommended methods
 of Cairns and Dickson(26).  Where possible samples were taken well above
 a sediment discharge, immediately downstream of the discharge, and at
 various locations well downstream of the discharge to determine the
 linear extent of damage.  For some streams at Northstar, it was impossible
 to obtain samples above the discharge from clear-cut ski runs.

Macroinvertebrates collected from each square foot of substrate were
placed in Mason jars with a preservative of 50 percent alcohol (95
percent), 5 percent glacial acetic acid, 10 percent formalin, 3 percent
 glycerine, and 32 percent distilled water by volume.   The samples were
 then dyed red with a rose bengal solution to facilitate hand picking of the
benthos from the bottom substrate and ditritus.  The macroinvertebrates
were sorted and identified to the lowest practical taxonomic level,
 (27,28,29) counted and weighed (i.e., dry weight at 103 degrees centigrade
 for one hour).

 Species diversity indices were calculated using numbers and weights for
each station.  The diversity index chosen was the Shannon-Weaver formula(30)
based on information theory.  The diversity index was calculated as:


     d" = -ZN±/N (In N±/N)

where "N" is the total number of individuals and "N-j_" is the total number
of individuals in each genus.

 In addition, the diversity index was  partitioned into two subcomponents:
 (a) species abundance or richness as  represented by the number of
species, "S", and (b) evenness as represented by e=d/log2S,  where "e" is an
index of distribution of individual organisms among species(31).

The approximate _t-test(32) was used to determine statistically signifi-
cant differences between stations in  regards to total numbers per square
meter (density).  This test is recommended for sample means whose
variances are heterogeneous.  In contrast,  a t-test defined by
                                  103

-------
Hutcheson(33), as recommended by Burgy and Knight(20),  was used for
comparing diversity indices.  The lattery-test employs the variances of
the diversity indices calculated from each station in computing t_ and in
computing the degrees of freedom.  Since, in all cases, the upstream
stations are considered to contain the natural benthic community of each
stream, the downstream stations were examined to determine whether
deviations from the normal community existed.

Percent similarity was also determined between stations to identify
differences in community types.  Percent similarity is defined as:
     PS = 100-0.5 E   (a± -
                                                      1 is the percent of
                                                      is the percent of
     where "S"  is  the total  number  of  species  present,  '
     individuals  in species  "i"  in  community  "A",  and  "t
     individuals  in species  "i"  in  community  "B"(34).

     Precipitation

     Battery operated,  heated (either  electric or  propane),  recording  rain-snow
     precipitation gages  were used  to  monitor precipitation  amounts  and
     intensities.   The recorders were  reset on a weekly basis.

     Snow Depth and Water Content (Northstar  only)

     Snow course  stations were established and samples  were  taken according to
     procedures established  by the  U.  S.  Soil Conservation Service(35) and  used
     by the California Department of Water Resources.   Samples  were  taken by
     steel snow sampling  tubes and  weighed on a scale  calibrated in  inches  of
     water.  Five samples per snow  course were taken on a bimonthly  to monthly
     basis.  Snow depth,  water content,  and snow density data,  and a qualita-
     tive description of  apparent soil moisture were recorded for each snow
     course.

C.   WATER QUALITY OF WEST MARTIS CREEK  (NORTHSTAR)

     The 10,500 hectare watershed of Martis Valley Creek is  located  immediately
     north of Lake Tahoe; however,  West  Martis Creek,  the area of investigation,
     contains only 1300 hectares.  Mean  annual precipitation ranges  from 60 to
     100 centimeters from the lower elevations to  the  top of Mount Pluto
     falling mostly as snow.  The stream flows down a  moderately steep course
     until it reaches Martis Creek  in  the valley floor.

     Soils of the watershed  are principally weathered  andesite derived from, a
     central ridge of volcanic material  which divides  Martis Valley  Creek
     watershed from Lake  Tahoe.   Higher  elevations are characterized by  shallow,
     stony soils  with a small amount of  organic matter and a low moisture
                                  104

-------
storage capacity.  Middle elevations have loam and clay  loam forest
soils.  Soils of the lower elevations are composed of  alluvium material
of which much of the valley floor is composed.

Upper ridges of the watershed sustain a fir forest with  descending
elevation, this converts gradually to a pine forest and  thence to a
sagebrush-grass zone.  Riparian areas are heavily  vegetated by willows,
alders, and other water-loving species.

The Northstar-At-Tahoe development,  which occupies a substantial portion
of this watershed (75 percent), has  been thoroughly described in Sections
III through V of this report.   Under predevelopment conditions, runoff,
and suspended sediment concentration levels were probably  quite low.
There was some runoff from skid trails and logging roads,  but flows did
not usually exceed the infiltration  capacity of the soils'.   Surface flows
at lower elevations in the watershed were fed by springs and groundwater
seepage.  Any overland flow was contained in naturally stabilized
drainage channels.

In order to determine the change, if any,  in sediment  yield for the West
Martis Creek watershed after the development of Northstar,  the
environmental monitoring sites shown in Figure VII-1 were  established.
A schematic diagram shown in Figure  VII—2 further  depicts  the relative
layout of significant drainages within the watershed as altered by the
Northstar development and the location of the suspended sediment sampling
sites.

Streamflow

The following continuous streamflow  recording gages were established in
the West Martis Creek watershed:

          Gage No. 1.  Situated above a 1.22 meter rectangular sharp-
          crested weir.   Located near the Big Springs  day  lodge on the
          West Fork of West Martis Creek.   Drainage area above this point
          is 294 hectares and extends to the summit of Mount Pluto at an
          elevation of 2,620 meters.  Approximately 113 hectares of forest
          land have been cleared for ski trails.   Flow over this weir
          is principally overland flow as spring water is  collected via
          an underground collection  system above this  point.   Groundwater
          collected by this system is transported  either to the water
          treatment plant or through a bypass structure  to  the V-notch
          weir (Site 5).

          Gage No. 2.  Situated above a 90 degree  V-notch,  sharp-crested
          weir.  Located on the East Fork of West  Martis Creek above the
          confluence with the West Fork.   The drainage area above this
          point is 471 hectares.   A  200,000 cubic  meter storage reservoir
          is located 2.4 kilometers  above this  sampling site.   All
          upbasin surface runoff is  collected by this  reservoir which
                                 105

-------
            KEY
I	L-   STREAM FLOW GAUGING
o
STATION

SNOW COURSE
       RECORDING RAIN  a SNOW
       PRECIPITATION GAUGE

       WEST MARTIS CREEK
 -*»-  ELEVATION CONTOUR (f»*t)
       WEST MARTIS WATERSHED
       ABOVE GAUGE NO. 3
        FIGURE  VII-1.   HYDROLOGIC  MONITORING  SITES
  WITHIN  WEST  MARTIS  CREEK  WATERSHED  (NORTHSTAR).
                                   106

-------
                           O cc
                           (D
    CO
                      <-> (K
                       :D
                      U- O
°>i
2 = !«
                           LU
                           r oc
                           Q ID
/
/
I
1
\
\
\
107

-------
          only briefly overflows  in  the  springtime of normal and wet
          years.   A groundwater collection system is located above this
          reservoir.   A bypass  valve spills excess water to the east fork
          about one-third of a  mile  below the  reservoir.  Extremely low
          flows have been observed in the east fork at  this point due to
          the limitation of bypass flow  from the groundwater collection
          system when the treatment  plant is functioning.

          Gage No. 3.  Situated above a  1.83 meter rectangular
          sharpcrested weir. Located on West  Martis Creek below a bridge
          approximately 0.2 kilometer north of the golf course club
          house.   Total drainage area above this point  is 1,308 hectares.
          The majority of the Northstar  development is  above this point.

          Gage No. 4.  Situated above a  1.22 meter rectangular
          sharpcrested weir. Located on unnamed tributary to Martis
          Creek.   Drainage area above this point is 220 hectares.
          Meadow, pasture, and  timber areas are located above this
          sampling point.

Figure VII-3 is a graph of the  total monthly flows monitored at Gage No. 3
for the duration of the erosion control  project.  Also  plotted is the
monitored extent of the snow pack water  content during  1975 and 1976.
Based upon the theoretical unimpaired runoff in the Truckee River
watershed, water year (October-September) 1975 was 13 percent above the
average runoff conditions for this area.. On the other  hand, water year
1976 was 62 percent below the average runoff conditions.  The difference
in water years was mainly attributable to the  lack of substantial
snowfall during 1976.

Snow Depth and Water Content

Six snow courses were established at Northstar to monitor snow depth and
water content of the snow pack.  The snow courses were  located
approximately in the middle of the succeeding  150 meter elevation contour
interval from the top to the bottom  of the West Martis  Creek watershed.
The snow courses were located as close to the  center line of the watershed
as was practical.  Snow depth and snow pack water content measured at
each snow course were assumed to represent the average  conditions for the
particular 150 meter contour elevation interval within  which it was
situated.  A summary of the estimated water  content for each snow course is
presented in Table C-l, Appendix C.

Precipitation

The electrically heated recording rain-snow  gage at Northstar was located
at the Water Treatment Plant near the base of  the ski hill.  The primary
purpose of this gage was to identify periods of rainfall for the purposes
of the water quality model.  This model  will be described later in  this
section.
                                 108

-------
to
O
CO
z
O
a:
UJ
a.

-------
The most intense rainfall recorded at Northstar occurred on September 10,
1975.  This storm lasted about one hour and had an intensity of
approximately 2.5 centimeters per hour.  This intensity is indicative of a
greater than 20-year storm based upon existing records for the area.   The
highest nonsnowmelt streamflows were also recorded on this date.

Suspended Sediment Samples

A total of 571 suspended sediment samples were collected at 31 sampling
sites around the West Martis Creek and adjacent watersheds.  The relative
locations of the 31 sampling sites are indicated schematically in Figure
VII-2.  The description of the individual sampling sites appears in
Table C-2, Appendix C.  A summary of the data collected at each sampling
site appears in Table C-3.

Suspended sediment concentrations clearly fluctuated greatly.  In most
instances, the suspended sediment concentrations appeared to be roughly
proportional to the type of runoff conditions and the instantaneous
runoff rate.  This relationship was closely investigated in the
development of the water quality model for Northstar and will be discussed
later in this section.

The highest suspended sediment concentration recorded in runoff from the
entire watershed (as measured at Gate No. 3) was 606 parts per million.
This sample was collected when the streamflow rate was 625 liters per
second during the peak spring snowmelt on April 24, 1975.  During this
same period, runoff tributary to West Martis Creek from areas disturbed
by the Northstar development reached suspended sediment concentrations
of 6,029 parts per million (Site 28, 5-22-75).

The highest suspended sediment concentration at Gate No. 3 during
rainfall conditions was 526 parts per million.  This occurred on
September 10, 1975, during the most intense storm recorded for the
duration of the erosion control project.  The flow rate at Gate No. 3
when the sample was taken was 240 liters per second.  Runoff from
disturbed areas tributary to West Martis Creek exceeded 8,000 parts per
million in certain instances.  The maximum recorded suspended sediment
concentration in the  total runoff from the up-basin ski area on this date
was 4,871 parts per million at a flow of 62 liters per second.  A summary
of the average suspended sediment concentrations monitored at the
instream gaging stations on West Martis Creek is presented in Table VII-1.

Analysis of the water quality data shows that suspended sediment
concentrations for a  given flow rate in the West Martis Creek drainage
system are highest during rainstrom events.  The lowest concentration
occur during periods  of low flow when snowmelt or rainstorm runoff is
absent.  Suspended sediment concentrations typically found during
snowmelt conditions, while not as high as during rainstorms, averaged
4-8  times that of low flow conditions.
                                  110

-------
                                 TABLE VII-1
                  AVERAGE SUSPENDED SEDIMENT CONCENTRATIONS
                    RECORDED AT INSTREAM GAGING STATIONS
                            ON WEST MARTIS CREEK
                           AVERAGE SUSPENDED SEDIMENT CONCENTRATION (ppm)*

                        Gage No.  1            Gage No. 2           Gage No. 3
Low Flow

Rainfall

Snowmelt
  4.2 (12)

944.0 (7)

 33.4 (16)
 4.2 (13)

53.7 (16)

28.9 (36)
* number of samples  taken indicated in parenthesis
  7.9 (13)

115.0 (20)

 28.5 (43)
    Benthic Macroinvertebrates

    Biological sampling stations at the Norths tar development were selected
    to illustrate effects on aquatic benthic macroinvertebrates by specific
    local land disturbances.   The following biological sampling stations,
    located as shown in Figures  VII-1 and VII-2,  were established on West
    Martis Creek:

              Station WM-I.   An  unnamed stream at Big Springs about 15 meters
              upstream of the main ski lodge.   The station was discontinued
              after the September 1974 sampling period when it was  covered to
              improve ski safety.  This station was  chosen as the site
              furthest above  development in the watershed.   Although most  of
              the ski area is above this station,  there is little adverse
              effect since much  of the runoff  from the ski area percolates into
              the ground in underdrains installed  for the  Northstar domestic
              water system and here enters  the stream.

              Station WM-II.   About 15 meters  upstream of  the water storage
              tanks and above the uppermost area of  condominiums  on the West
              Fork of West Martis  Creek.  This  station  was  chosen to
              represent the macrobenthic community just above the Northstar
              development  complex and  was thought  to  be a  community relatively
              "undisturbed" by pollutants.
                                     Ill

-------
Station WM-III.  Just above the first major culvert (Village
Culvert) discharge on the West Fork of West Martis Creek.   This
station represents the macrobenthic community just above the
discharge of the Village Culvert (Village Center commercial
area).  Though this station would receive runoff from
unrevegetated sections of the ski area and uncontrolled
drainages, it was intended to serve as a reference station to
compare with Station WM-IV.

Station WM-IV.  Just below the discharge point of the Village
Culvert on the West Fork of West Martis Creek.  It was antici-
pated that the discharges from this ^culvert would have a great
impact on the macroinvertebrates at Station WM-IV due to the
heavier loading of silts and sediments and parking lot runoff
(oils and grease).

Station WM-V.  About 50 meters upstream of Northstar Drive
Stream crossing on West Martis Creek.  This station was
established as a reference station for Station WM-VI.

Station WM-VI.  About 15 meters downstream of Northstar Drive
Stream crossing on West Martis Creek.  This station is
immediately below the discharge from two large drainage ditches
from condominiums and parking lots and is below an extensive
fill area on Northstar Drive.  The roadway fill shows signs of
erosion into West Martis Creek.  The macrobenthos at Station
WM-VI were expected to be more adversely affected from local
surface runoff than were the macrobenthos at Station WM-V which
was more remote from direct influences of point discharges
to West Martis Creek.

Station WM-VII.  Just upstream of Gage 3.  This station was
assumed to be adversely affected as it received runoff from the
entire Northstar development, including the golf course which
was constructed and completed during this study.

Station WM-VIII.  Just upstream of Gage 2 on the East Fork of
West Martis Creek.  This station was to serve as a reference
station to compare with "reference" stations on West Martis.
As the only unnatural sources of silt and sediment are from a
dirt road crossing 2.4 kilometers upstream, it was originally
assumed that this station represented a "natural" or "clean-
water" community.  Unfortunately, however, the East Fork of
West Martis is a controlled flow and it is possible that this
condition could affect the benthic population.

Station WM-IX.  About 100 feet above Gage 4.  Station WM-IX is
the other "clean-water" or "normal" community reference station
in this unnamed tributary to Martis Creek.  A limited number of
                       112

-------
            cattle are pastured about one-half mile upstream.  There is no
            development or unnatural soil disturbance such as roadways,
            buildings, etc. in this watershed.

  The results of the benthic macroinvertebrate monitoring program are
  summarized in Table VII-2.

  In all of  the five sampling seasons, only one season showed any
  significcant differences between stations of .the standing crop estimate
  (number/meter ).   This occurred at Stations WM-III and WM-IV sampled on
  September 1974.   As can be seen in the graph (Figure VII-4),  all orders
  Insecta and Oligochaeta had a significantly lower population at Station
 WM-III, below the discharge of the Village Culvert,  than the reference
  Station WM-III, which is upstream of the Village Culvert.   The total
 number of families  declined from 21 above to 18 below the Village
  Culvert.   However,  this decrease in families is not  significant as  the
 diversities of these two communities are not significantly different.
 The Diversities recorded there were also two of the  highest diversity
 indices recorded  during the entire West  Martis  study (Table VII-2).

 The September  1974  macroinvertebrate collection could not  be correlated
 to water quality  as there was  no background data available at that  time
 However,  the significant differences  in  standing crops  between  Stations'
 WM-III and WM-IV were  obviously  due to discharges  from  the Village
 Culvert.   Accumulated  sediment  in the rock  lined ditch  below  the  culvert
 outlet suggested  that  discharges  of suspended sediment  did occur  due  to
 previous  construction  activities,  winter road sanding activities, and
 exposed road cuts in the parking lot area.

 The July  1975  collection revealed a general  decrease in species abundance
 and standing crop from Station WM-III to Station WM-VI.  This is most
 likely related to the  steady increase in average suspended sediment
 concentrations between Gage No. 1  and all the water sampling points
 through to  Station WM-VI  (from 18.8 parts per million to 73.3,
 respectively, during the first six months of 1975).

 The December 1975 collection revealed some perturbations at Stations WM-II,
 WM-III, and WM-IV, where low diversities were found.   Though water quality'
 sampling was limited to spot sampling during low flows and runoff events
 after  July  1975,  siltation problems were still evident.   High runoff
 suspended sediment concentrations were observed in the upper watershed
 near the affected stations.  Drainage from the T-l lift above the Village
 Culvert had an average of 2,866 parts per million and a maximum of 8,339
 parts  per million, while Village Culvert averaged 688 parts per million
 and a maximum of  1,093 parts per million during runoff events.  Down-
 stream near Station 4,  the average runoff conditions  were 1,791 parts per
million, with a maximum of 6,757 parts per million.  In  previous stud-
 ies (3), runoff conditions of lower concentrations (100-1,200 parts per
million) had a far more severe impact on  the macroinvertebrate community
 than is seen in this study of the West Martis Creek watershed as affected
by the Northstar development.
                                 113

-------
CM
H

      w
      CU
1
       H
       en
       M
       1
 O
 3
 w
 &
        Pn
    V   p
        en
        3
              M
H
H
H
               M
                  m  -H
                   0)  0)
                   •U  rH
                   0)  H
                           OO
                           H
                                 O  O H
                              in in  OO -d"
                           in CM
                           in oo -3- 01 r~~
                           OO CM rH OO OO
                           oo o m en o°
      en rH  rH -*  00
      O\ rH  CM vD  r^
      rH vo  oo en  m
      CM rH     rH  rH
                           co
                               oo
                           in  ro r-
                                     oo  en
                                         co
                           CM
                           oo
                           CM
                                  rH rH  rH
             en 
                                                                     CM  CM
                                                                                   CM
                                                                     in  CM cy>  o1! i~>
                                                                     OO  rH OO  OO en
                                                                            CM CM rH rH  CM
                                                                                m m
                                                                                   CO
          en en
rH  en O O rH


O  O rH O rH
                                                                              m r^  oo en
                                                                              m  o oo r~ o
                                                                               ys m   r~ CM ^O  O
                          O  O H O  rH
                                                          114

-------
           1,100

           1,000

            000

            800




            600

            500

            400

            300

            200

            100

             0
WEST  MART IS  CREEK
MACRO INVERTEBRATES
  SEPTEMBER,  1974

       LEGEND
                    N
                    a
                    *_
                    tPH
   EPHM - EPHEMEROPTERA
   PLEC - PLECOPTERA
   TRIC - TRICHOPTERA
   DIPT - DIPTERA
   COL  - CQLEOPTERA
   OLIG - OLIGOCHAETA
                           PLE
                                                        OLIG
   Figure VII-4.  West Martis Creek Macroinyertibrates,  September  1974,
The June 1976 collection revealed unusually low'diversities.  This was
probably due to the low flows (due to drought conditions) and lack of
flushing action which created deposits of sediment.  Sediment deposits
were also seen along the stream banks in the November 1976  collection, but
not so heavy as in the June collection period.  There were  three small
rainfall events in the fall which could have aided in flushing some excess
sediments downstream.  This could be seen in the November 1976 collection
as diversity indices and evenness estimates improved.

Although Surber sampling stations for benthic macroinvertebrates were
established to monitor areas in the Northstar development where sediment
and erosion problems were suspected to occur, the macrobenthic community
only suffered minor pertubations.  The results did not illustrate the
impact which has been observed in other studies which have documented the
impact of eroded sediments on benthic macroinvertebrates(3,36,37).  The
primary reason for an absence of perceptible impacts on the macrobenthic
community is the extremely low sediment yield for the Northstar
development.  The suspended sediment load computer-simulation program,
discussed later in this section, has shown that the Northstar
development has resulted in a less than one-fold increase in suspended
                                 115

-------
     sediment yield above natural background  levels.  While this increase has
     been perceptible from a water quality monitoring standpoint, it does not
     appear to have resulted in an adverse impact on the macrobenthic community.

D.   WATER QUALITY OF LONELY GULCH CREEK (RUBICON PROPERTIES)

     The watershed of Lonely Gulch Creek has  275 hectares with a mean annual
     precipitation of 104 centimeters  mostly  as snow.  The stream follows a
     moderately steep course until it-  reaches Lake Tahoe at Rubicon Bay
     (Figure VII-5).

     The soils of the watershed are entirely  a decomposed granite formation,
     except at lower elevations near the lakefront which consists of glacial
     moraines.  The upper reaches of the study area are dominated by
     moderately deep to shallow, coarse textured rocky soils over weathered
     granitic bedrock; the lower reaches by a zone of gravelly and stony soils
     with pans formed in glacial moraines and outwash.  Adjacent to the lake
     deep soils on alluvial fans and outwash  are found.  Most of the watershed
     is covered with a relatively dense mixed coniferous forest down to the
     lakeshore.

     Before it receives any discharge  from disturbed lands, Lonely Gulch Creek
     flows into a small reservoir used for domestic water supply.  Below this,
     the Creek flows through the Rubicon Properties Subdivision, the main land
     disturbance in the watershed.  Steep roadcuts (30 to 45 percent, up to 25
     meters long) and homesite excavations have created an accelerated source
     of fluvial sediment.  Rubicon Properties is thoroughly described in
     Section VI of this report.

     Additionally, during the spring and summer of 1973, extensive sewer
     construction occurred in the Rubicon development and along Lonely Gulch
     Creek.  The stream bank was altered to accommodate the sewer line and
     the line also crossed the Creek at the lower end of the Subdivision.
     The locations of the various streamflow  gages, water quality sampling
     sites, biological sampling stations, and the precipitation gage are
     shown in Figure VII-5.   These monitoring locations were established to
     determine the comparative sediment yield and water quality impacts of
     the undisturbed upper watershed (2.37km  ) with the heavily disturbed
     lower watershed (0.38 km ) •
     Streamflow

     The following continuous recording gages were  established in Lonely Gulch
     Creek to monitor streamflow:

               Gage No.  5.   Situated above a 1.22 meter  rectangular sharp-
               crested weir.   Located just below the  domestic water supply
               storage reservoir on Lonely Gulch Creek.  Drainage area above
               this point is  237 hectares  of undisturbed watershed.
                                      116

-------
                                     LEG  END
                                     OLOGIC
                                   STATIONS
                              [	j  BIOLOGICAL SAMPLING
O                                   WATER QUALITY SAMPLING
                                   SITE
                                   WEIR  WITH STArL REPORDLR

                              -•*-  DRAINAGE PATTERN
                                           STATE  OF  CALIFORNIA
                                    STATE WATER RESOURCES CONTROL BOARD
                                      LONELY   GULCH   CREEK
                                          WATER   QUALITY
                                      MONITORING   DIAGRAM
100     200

 I         I
SCALE  (METERS)
                                   DEMONSTRATION  OF  EROSION  AND
                                    SEDIMENT  CONTROL TECHNOLOGY
                             117

-------
          Gage No.  6.   Situated above  a  1.22 meter rectangular sharp-
          crested weir.   Located 180 meters above mouth of Lonely Gulch
          Creek and below all major land disturbance in the Lonely Gulch
          Creek watershed.   Total drainage area above Gage No. 6 is
           ""5 hectares.

Figure VII-6 is a graph of the  total monthly  flows monitored  at Gage No. 5
during the periods  which the gage was  maintained.  Substantial amounts of
water are diverted above Gage No. 5 for  domestic water supply for Rubicon
Properties Subdivision.  As was true in  West  Martis  Creek, streamflow in
Lonely Gulch Creek in 1976 was  substantially  lower than 1975  streamflow
due to the considerably reduced winter precipitation levels during 1976.

Precipitation

The propane heated recording rain-snow gage at Rubicon Properties was
located near the upper water supply storage tank off of Highland Drive.
As was true at Northstar, the primary purpose of the precipitation gage
was to identify periods of rainfall for use with the water quality model.

Although several rainstorms occurred in the Lonely Gulch  Creek watershed,
none of the observed storms were as intense as the one recorded  at
Northstar on September 10, 1975.  The most intense storm of record
occurred on August 16, 1976, with a maximum intensity of  1.0 centimeter
per hour.  Total rainfall for a  two-day period starting the previous  day
was 8.25 centimeters.

Suspended Sediment  Samples

A total of 301 suspended sediment samples were collected within the
Lonely Gulch Creek watershed during the periods of September 1972 through
 September 1973 and June  1975 through  September 1976.  The relative
 locations of the sampling  sites  are indicated in Figure VII-5.
 Descriptions of the individual  sampling sites appear in Appendix C,  Table
 C-4.   A summary of the data collected at each site appears in Table C-5.
Variations  in the  suspended sediment  concentration were extremely
 erratic due to the extensive concentrated disturbances and erosion
 sources in an extremely small watershed.  For example, small amounts of
 eroded sediment might  build up in one location after a series of small
 runoff events.  The initial stages of a subsequent large  runoff event
 would then have an astronomical suspended sediment  concentration.  The
 highest concentration of suspended sediment  in runoff within Rubicon
 Properties Subdivision was 231,000 parts per million.  The highest
 instream sediment sample was collected  where Lonely Gulch Creek passes
 under State Highway 89 with a  concentration of 15,200 parts  per million.
 In all cases, the suspended sediment  concentrations were  dramatically
 higher during periods of rainstorm runoff  than during snowmelt runoff.
 It was estimated that at the peak of  a  two-day,  5.54-centimeter
 rainstorm on October 10 and 11, 1975, that up  to 15 metric  tons of
                                   118

-------



10
-r in
O|
^
UJ (5
CC
=> H
2 UJ
Ul
co tr
< 0
UJ >.
o _
" c













- 	 - ••-


J^_

	 1




I









r



DATA
— NOT —
COLLECTED






<3- ro oj
O 0 0
CNOW/gOl * SNOi) MO
i
\

ZD

-
-




*P
L
J8qUJ808Q
-
J3GUI9 330
Xjonuop



Xjonuop
X|np op
(O
a
IT)
m

^3-
to

CVJ
0 0
~uwv3yis

Q
CC
o
CD
—I
ATE OF CALIFORN
ER RESOURCES CONT
"S
UJ
h-
1—

STREAMFLOW
LONELY GULCH CREEK
FI«UKE NUMBER 1
VII- 6 |
DEMONSTRATION OF EROSION AND
SEDIMENT CONTROL TECHNOLOGY
CO
N.
O)
"*" O)
DC
2 ™
I 1
x 2 UJ
O 5 £ x
DC g g
'Mi
CM I
N. H-
O)
i- IO
5
m
^ Ul
UJ -Z.
> ^
o ->
•z.
119

-------
suspended sediment were being discharged to Lonely  Gulch  Creek in a
single hour.

These high rates of sedimentation have devastated Lonely  Gulch Creek.
Above the first sediment discharge point from Rubicon Properties
Subdivision, Lonely Gulch Creek has the appearance  of a small pristine
mountain stream.  However,  by the time it has wound its way  down through
the Subdivision, Lonely Gulch Creek is choked by deposited sediments.
The deposition is evidenced to some degree by the reduction  of recorded
suspended sediment concentrations as the stream gradient  decreases
towards Lake Tahoe.  This is due to increased settling and suspended
sediment deposition.  The highest suspended sediment levels  on Lonely
Gulch Creek were at Rubicon Glen Drive (Site 34) and Highway 89  (Site 35),
less than 100 meters downstream from the most severe sediment discharges
from Rubicon Properties Subdivision and about 900 meters  above Lake Tahoe.
By the time a slug discharge of suspended sediment  to Lonely Gulch Creek
has reached Gage No. 6 (Site 36), only 150 meters above Lake Tahoe,
suspended sediment concentrations are usually quite diminished.

A summary of the average suspended sediment concentration monitored at
the instream sampling stations above and below Rubicon Properties
Subdivision is presented in Table VTI-3.

Benthic Macroinvertebrates

The following biological sampling stations, located as shown in
Figure VII-5 were established on Lonely Gulch Creek:
          Station LG-1.
100 meters above all road and land development
The Creek in this area is typical of a Sierra
          disturbances.
          Mountain forest stream.

          Station LG-II.  70 meters above Station LG-III and approxi-
          mately 200 meters below Station LG-1.  It is above a large
          swale which drains the steeper and more extensive roadcuts of
          Rubicon Properties.  Although this station receives minor
          drainages from roadcuts and fills, it serves as a "reference"
          station for Station 3.

          Station LG-III.  50 meters below the start of road and
          subdivision disturbance and about two meters below the first
          three drainage swales which collect most of the street runoff
          from the roadcuts.

          Station LG-IV.  25 meters above State Highway 89 and 250 meters
          below Station LG-III.  It was below most of the drainage swales
          which collect surface runoff from Rubicon Properties.

 As  in a previous study of Lonely Gulch Creek(3), the downstream stations
 had lower standing crop estimates  (Total No. Individuals/m ), lower
                                  120

-------
                                 TABLE VI I-3
                  AVERAGE SUSPENDED SEDIMENT CONCENTRATIONS
                   RECORDED AT INSTREAM SAMPLING SITES IN
                LONELY GLUCH CREEK ABOVE AND BELOW DEVELOPMENT
                               AVERAGE SUSPENDED SEDIMENT CONCENTRATION (ppm)*
Low Flow

Rainfall

Snowmelt
                                   ABOVE
                                DEVELOPMENT
 1.3 (38)

20.8 CIS)

 9.1 (41)
   BELOW
DEVELOPMENT


   12.9 (36)

 1798.1 (33)

  434.6 (45)
* number of samples taken indicated in parenthesis
     diversities,  and,  ±n most cases,  lower  species  abundance than the control
     Station  LG-1  for all periods  of collection.   "Reference" Station LG-II
     also  contained a higher  standing  crop estimate  and a  equal  or higher
     species  abundance  than downstream Station LG-III  for  all periods of
     collection.   The results  of the benthic macroinvertebrate monitoring
     program  conducted  in the Lonely Gulch Creek watershed are summarized
     in Table VII-4.  Figures  VII-7, 8,  9, and 10  graphically depict  the
     standing crop estimates  for the July 1975, December 1975, June 1976,  and
     November 1976 sampling periods respectively.  The increasing  impacts, as
     one moves downstream, are clearly  indicated by  the reduced  numbers of
     individuals in representative orders at each  successive  downstream
     station.

     The decrease in species abundance,  diversity, and  standing  crop  estimates
     in the downstream macroinvertebrate communities is  well  correlated with
     the downstream increase in suspended sediment for  the July  and December
     1975  collections.  Runoff into Lonely Gulch Creek  below  Station  LG-II
     ranged from 1,500 - 250,000 parts per million in drainage ditches and
     culvert  outlets.  However, during  the December  1975 - June  1976  sampling
     period,  no significant rainfall events  took place  to create the  heavy
     silt  laden runoff as seen in previous sampling.  The snowmelt produced
     little runoff and low flows due to  the very light winter.   Consequently,
                                     121

-------
1,100 •
1,000 •

900 •
800 •
CM
B
o: • 700 •
Ul
„ 600-
^>
o SOO -

g 400-
300 -
200-
100









LONELY GULCH CREEK
MACROINVERTEBRATES


JULY




LEG







-







-
•

al
S3
EPHU

^

d
3
I









•

H
_J












33 2
PLEC '















, 1975

END





EPHM - EPHEMEROPTERA
PLEC - PLECOPTERA
TRIC - TRICHOPTERA
DIPT - DIPTERA
OLIG - OLIGOCHAETA



•
^r
a IK Ht4
to mm «P <•



ft
1,

5p
TRIC DIPT





H
O
_l
|~o



•ffl
1 1
Jil
Dlolia
LIB
Figure VII-7.  Lonely Gulch Creek
  Macro invertebrates., July, 1275.
1,100 •
1,000
900 •
800 -
CM
E
a: 700 -
UJ
„ 600
o 500 -
g 400
300
200
100
0



LONELY GULCH CREEK
MACROINVERTEBRATES
DECEMBER, 1975
LEGEND






<»
HE
EPHM-
PLEC -
TRIC -
DIPT -
OLIG -

p

1_ Tfl Tn
u. ^H^H nMN|H
to to to o to <* «» <» «>|HM PLEC TRIC
EPHEMEROPTERA
PLECOPTERA
- TRICHOPTERA
DIPTERA
OLIGOCHAETA


B
-, n
jM|atl H^n^
;*p3 53Jg3
DIPT OLIG
Figure VII-8.  Lonely  Gulch  Creek
Macroinvertebrates,  December,  1975.

                 122

-------
1,100 •
1,000-
900 •
CM 800 •
5 700-
0.
I
_j





i
o e





H
to
_i
PLEC









H
o



LONELY
MACRO
J



GULCH CREEK
NVERTEBRATES
UNE, 1976
LEGEND

EPHM - EPHEMEROPTERA
PLEC - PLECOPTERA
TRIC - TRICHOPTERA
DIPT - DIPTERA
OLIG - OLIGOCHAETA


H

.
B
H-RIC





"



u> ta
_i _i


0 »0
DIPT OL


[.

IG
Figure VII-9.  Lonely Gulch Creek
  Macroiiwertebratea, June,  1976.
1 , 1 00 -
1,000-
900-
800-
E

-------
TABLE VII-4
RESULTS OF

UNITS
2
Number/m



No. of Families



Diversity



Evenness



SURBER SAMPLING AT FOUR STATIONS ON
DATE OF
COLLECTION
7-08-75
12-08-75
6-18-76
10-04-76
7-08-75
12-08-75
6-18-76
10-04-76
7-08-75
12-08-75
6-18-76
10-04-76
7-08-75
12-08-75
6-18-76
10-04-76
LONELY GULCH
LG-I
1542
1321
2125
1560
20
19
14
14
2.497
2.247
2.150
2.207
0.58
0.53
0.56
0.58
LG-I I
398
945
1465
496
14
12
13
14
1.962
1.464
1.582
2.072
0.51
0.41
0.43
0.54
LONELY GULCH CREEK
STATIONS
LG-III
244
245
1366
99
11
12
13
09
1.988
1.996
1.405
1.938
0.57
0.56
0.38
0.61

LG-IV
267
277
1652
19
09
12
14
04
1.913
2.077
1.846
1.352
.60
.58
.48
.67
low flows and low suspended sediment created few interstation
differences between species abundance and standing crop  estimates  for  the
June 1976 collection.   Station LG-I was decreased to only 14 families
probably because the low flow drought conditions eliminated the rarer
families.  Changes in water level or current have been known to change
whole communities (38,39,40).

In the four month period preceding the November 1976 sampling period,
three rainstorms produced runoff in drainage ditches which discharged
just above Station LG-III producing an average runoff concentration of
6,600 parts per million and a maximum of 15,157 parts per million  in
Lonely Gulch Creek at Station LG-III.  The drainage ditch above Station
LG-IV had an average runoff concentration of 10,211 parts per million  and
a peak value of 32,756 parts per million.  Lonely Gulch Creek at Station
LG-IV had an average runoff condition of 7,183 parts per million of
suspended sediment.  The results of these storms, runoff, and low
baseline flows could be seen in the stream substrate.
                                124

-------
     During all sampling periods, Station LG-1 had the "normal" substrate of
     cobble, pebble, gravel, and some sand while Station LG-II had the same
     except for a slightly higher percentage of sand and some silt.   At
     Station LG-III, the cobble was "cemented" in by sand and silt while at
     Station LG-IV it was completely overwhelmed by a silty sand with the
     cobble, pebble, and gravel buried beneath.  The effect of these substrate
     conditions on the macrobenthic community is obvious.   The macrobenthic
     community at Stations LG-III and LG-IV were almost  eliminated in the
     November 1976 sampling period.   The need for sound  land management and
     effective erosion control practices is amplified by the results of this
     study.  High suspended sediment concentrations coupled with low flow
     conditions have created an adverse effect on the macroinvertebrate
     community of Lonely Gulch Creek and nutrient contributions  from suspended
     sediment.

     The ongoing erosion control work in the Lonely Gulch  Creek watershed at
     Rubicon Properties will be monitored in the future  for its effectiveness
     in stream recovery and lessening sediment loading to Lake Tahoe.

E.   WATER QUALITY MODELING OF SUSPENDED SEDIMENT TRANSPORT

     In order  to determine  mass  emission rates  for  suspended sediment from
     both the'Northstar and Rubicon  Properties  developments, a simple "model"
     to predict these loads was  sought.   Suspended  sediment transport at both
     the project sites  had  a seemingly proportional relationship with the
     amount of  streamflow.   This  first task was to  determine the type of
     relationship  that  would reliably predict the suspended sediment
     concentration for  a given streamflow.  Because continuous streamflow
     recordings were available at three  streamflow gages  in the West  Martis
     watershed  and two  in Lonely Gulch Creek,, such relationships would define
     the amount  of suspended sediment transported past each gage for any given
     period of  time.

     Admittedly, such an approach is simplistic, as suspended sediment
     levels can be quite different for a given flow level depending on whether
     a  sample is taken at the beginning or end of a runoff period.  Nonetheless
     the project staff felt that a well correlated average relationship between'
     these extremes would yield acceptable estimates of overall suspended
     sediment mass emission rates.  Certainly such relationships, if  reasonably
    well correlated, would yield acceptable estimates for comparative purposes
     (.i.e., post-development versus pre-development, or upstream versus
     downstream sediment loads).

     Initially, one mathematical expression relating suspended sediment  to
    streamflow was sought for each streamflow gaging station.  However,
     correlations for such a single expression were generally extremely  low.
    From this point, the project staff sought to define  more than  one
    expression at each  gaging station depending on the varying types  of
    runoff.  The following runoff types  were identified  and defined:
                                     125

-------
         Rainstorms.  These runoff periods were defined by the recording
         precipitation gages at Northstar and Rubicon Properties.   An
         added requirement of these periods was that they must cause a
         perceptible rise in at least one of the recording streamflow
         gages.

         Stage I Snowmelt.  These periods were defined as beginning when
         snow first remained without melting at the start of the winter
         season and ending when the maximum runoff period was reached
         in  the spring.  Early snowstorms which melted immediately during
         the fall were treated as rainstorms.

         Stage II Snowmelt.  These periods began after the peak runoff
         period was reached in the spring  (i.e., the end of Stage I) and
         ended when diurnal streamflow fluctuations from snowmelt were
         no  longer significant and runoff approached low flow levels.

         Low Flow.  These periods occurred from the end of Stage II
         snowmelt until  the commencement of Stage I snowmelt the
         following winter, except as  interrupted by snowmelt conditions.

In all cases, suspended sediment concentrations were assumed to never be
less than that  defined by the mathematical  expression for low flow.  The
various mathematical expressions defining  suspended sediment concentra-
tions for a particular flow  type were  derived  by means  of linear
regression  analysis.   In  all cases, linear  regression gave better
correlations than did exponential, power law,  or logarithmic curve  fits.

Once the suspended sediment  versus flow relationships were established
with well defined periods of applicability,  they were  combined with
previously digitized streamflow data  to produce estimates  of suspended
sediment concentrations and sediment mass  emission rates  on  a  daily basis.
At each streamflow gage and each streamflow type,  the data was  summarized
on a daily, monthly, and, where possible,  yearly basis.  These
summarizations for each gage appear  in tabular form in Appendix C,  Tables
C-8 through C-13.

                          WEST MARTIS CREEK

The basic equations correlating suspended sediment concentration (SS mg/1)
with streamflow  (Q I/sec) for each of the streamflow gages are given in
Table  VII-5.  In most instances, confidence levels based on a Student s
t-distribution analysis were greater  than 99 percent.  In all cases, well
correlated relationships could not be developed for low flow conditions;
thus,  for low flow, the  average recorded suspended sediment concentration
was used irrespective of streamflow.  This is a reasonable simplification
due to the  relatively insignificant sediment  concentration found during
low flow periods.  Fluctuations in the assumed suspended sediment
                                  126

-------
concentrations during low flow period yield an insignificant variation in
overall calculated sediment mass emission rates.

Considerable problems were encountered in trying to determine suspended
sediment relationships for predevelopment conditions in the West Martis
Creek watershed.  Only scattered water samples had been taken at a low
frequency and usually during only low flow conditions.   However, at the
site designated Gage No. 3 (Site No. 3) for the erosion control project,
nine samples at various streamflow rates had been collected prior to
July 1971.  This was before extensive construction activities began at
Northstar.  Unfortunately, turbidity (JTU) was the only parameter recorded
which could be related to suspended sediment concentration levels.  To
provide a reliable substitute for direct suspended sediment samples, a
linear regression analyses was performed to correlate turbidity (JTU)
with suspended sediment (mg/1) for 28 samples collected at Gage No.  3
between October 25, 1974, and May 29, 1975.  The data correlated extremely
well with a confidence level greater than 99.99 percent, as determined by
a Student's t-distribution analysis.  Thus, using this  suspended sediment
versus turbidity relationship, suspended sediment concentrations were
estimated for the nine predevelopment samples.  The maximum estimated
suspended sediment concentration developed in this manner was 73 mg/1 for
a predevelopment rainstorm (November 25, 1970) sample taken at Gage No. 3
when-streamflow was 340 I/sec.  The turbidity recorded  at this time was
12.0 JTU.

A graphical presentation of the suspended sediment concentration versus
streamflow relationships for Gage No. 3 is shown in Figure VII-11.  The
relationship for the various postdevelopment flow types are indicated
by the solid lines as compared to the estimated predevelopment
relationship for all flow types by the dashed line.   As seen in Figure
VII—11, the primary departure from predevelopment suspended sediment
concentration appears to occur during rainfall and "Stage I" snowmelt
conditions.

The relative suspended loads for the .various postdevelopment flow types
are listed in Table VII-6.  In most instances, the majority of suspended
sediment load to West Martis Creek occurred during snowmelt periods,
principally during the heavy spring-melt period.   The only apparent
exception to this was runoff from the Northstar ski area during water
year 1975.  The vast majority (79.3 percent) of the suspended sediment
load that year came during rainfall periods.  A partial explanation  is
that much of the overland flow from the ski area  is  percolated and
intercepted by a groundwater collection system for water supply purposes.
This results in only very intense rainstorms actually producing any
measurable overland flow.   The water intercepted  by  the collection
system is  usually discharged back to West Martis  Creek  immediately after
collection, except as needed for domestic supply.   The  collected
groundwater flow typically has very low suspended sediment concentrations.
A graphical presentation of the suspended sediment loads in West Martis
                                 127

-------
CORRELATION OF SUSPENDED SEDIMENT CONCENTRATION
               WITH STREAMFLOW AT  GAUGE *  3
              WEST MARTIS CREEK (NORTHSTAR)
 LU
 o
 2
 O
 O
 Ul
 o.
 CO
    1,000

     800
                          .PREDEVELOPMENT

                          (ALL  FLOW  TYPES)
                                                             STAGE I

                                                           SNOWMELT
STAGE II
SNOWMELT
         10     20     40  60 80 100    200    400 600800 1000   2000

                       STREAM FLOW  ( LI TERS/SEC.)
                                             STATE OF  CALIFORNIA

                                       STATE WATER RESOURCES CONTROL BOARD
                                             STREAMFLOW

                                             WEST  MARTIS
                                      DEMONSTRATION  OF  EROSION AND
                                       SEDIMENT CONTROL TECHNOLOGY
   1
FKURE NUMIER

  VII-11
                                 128

-------
TABLE VII-5 s
SUSPENDED SEDIMENT CORRELATIONS FOR
WEST MARTIS CREEK
RUNOFF TYPE CONVERSION*
Gage No.
1. (lust below maioritv of ski area")
Rainfall SS=75.9(Q)+151.
All Snowmelt Types SS=1.82(Q)+1.00
Low Flow SS=4.18
Gage No.
Rainfall
Stage I-
Stage II
Low Flow
Gage No.
Rainfall
Stage I
Stage II
Low Flow
Gage No.
All Flow
* Note: -
2. (on East Fork, West Martis Creek,
SS=3.49(Q)-49.82
SS=2.78(Q)-55.33
SS=.326(Q)-4.70
SS=4.01
3. (on West Martis Creek below all dc
SS=1.14(Q)-68.4
SS=.397(Q)-34.3
SS=.078(Q)+1.90
SS=7.75
3. (Pre-development)
Types SS=.121CQ).+.085
SS = Suspended Sediment Concentration
Q = Streamflow (I/ sec)
DATA
POINTS
7
16
12
at confluence
15
27
10
13
jvelopment)
18
28
10
13
9
Cmg/1)
PERCENT
SIGNIFICANCE
>99%
>99%
N/A
with West Fork)
>95%
>99%
>98%
N/A
>99.9%
>99.9%
>99.9%
N/A
>99%

Creek during 1975 and 1976 is presented in Figure VII-12.  By comparing
this graph to Figure VII-3, it is possible to see how suspended
sediment loads do fluctuate with various levels and types of streamflow
within West Martis Creek.

Suspended sediment loads at Gage No. 1 are representative of the
disturbances within the ski area portion of the development.  Gage No. 2
loads are representative of input from the East Fork of West Martis
Creek, while Gage No. 3 loads are assumed to represent the total sediment
load from the entire upstream watershed.  Thus, any increase in sediment
load between Gage No. 1 and Gage No. 3,  minus the East Fork input, is
assumed to be from the heavily developed portions of the Northstar
development (condominiums, roadways, Village Center, parking areas, etc.).
                                  129

-------
               SUSPENDED  SEDIMENT  LOAD


        IN  WEST  MARTIS  CREEK  (NORTHSTAR)


     ESTMATED  BY WATER  QUALITY  MODEL  FROM


     OCTOBER,  1974  THROUGH SEPTEMBER, 1976
cc
UJ
a.

CO

o



o

o
z:
UJ
o
UJ
CO


o
LlJ
O
a.
CO
130-
120-
no
100
90-
80-
70
60
50
40-
30
20
10
0
SNOW
- SPRING











>•»
i—
a
3
a
o
-o
MELT ^
, 1975










r-T
i_
«
"i
O3
CJ
«
a
1974

\

\
\





at




















!••
J
-*.







/
/
/ (

n,
llr
»< w
i 1
° i
a
1975












RAINSTORMS
s FALL,
^SNOWME
iy t o
IT
SPRING, 1976
\ RAINSTORMS
— X — 1 CA 1 1 IQ7fi —
\ 1 rALL, iy /o
\Xi
— — ^«^
\,,,
£• fe
1 1
o a>
-3 0

-------
TABLE VI I- 6
POST-DEVELOPMENT SUSPENDED SEDIMENT CONTRIBUTION
TO WEST MARTIS CREEK (NORTHSTAR) FOR
VARIOUS FLOW TYPES
FLOW
TYPE


Low Flow
Rainfall
Snowmelt
Total

Low Flow
Rainfall
Snowmelt
Total
% OF
TIME


39
5
56
100

46
4
50
100
SUSPENDED SEDIMENT LOAD (METRIC TONS)
GAGE


0
47
12
59

0
0
0
0
#1

-
.08
.54
.34
.96
-
.03
.05
.11
.19
% GAGE #2 %

- WATER
0.1
79.3
20.6
100.0
- WATER
15.8
26.3
57.9
100.0



' GAGE #3



°/ •
/a

YEAR 1975 - -
0.
5.
12.
18.
58
35
21
14
3.2
29.5
67.3
100.0
8.
48.
179.
236.
46
66
SO
42
3
20
75
100
.6
.6
.8
.0
YEAR 1976 	
0.
3.
11.
15.
65
03
72
40
4.2
19.7
76.1
100.0
3.
11.
12.
27.
29
76
89
94
11
42
46
100
.8
.1
.1
.0
Table VII-7 is a summarization of the suspended sediment load per unit
area from the various portions of Norths tar as calculated in this manner.
The postdevelopment loads are compared with the estimated predevelopment
suspended sediment load from the entire watershed.  Lacking any
significant detailed information on tributary predevelopment loads, the
total predevelopment suspended sediment load was estimated for the
postdevelopment years for which, streamflow records existed.  Had the
Northstar development not occurred, the unit suspended sediment load would
have been an estimated 12.34 metric tons per square kilometer compared to
an actual 24.12 metric tons per square kilometer for water year 1975.  For
water year 1976, a much drier year than 1975, suspended sediment load
would have been an estimated 1.47 metric tons per square kilometer
compared to an actual 2.85 metric tons per square kilometer.  Thus the
overall postdevelopment loads are estimated to have increased almost 100
percent due to the construction of Northstar.  For water year 1975, unit
                                   131

-------
TABLE VI I- 7
SUSPENDED SEDIMENT LOADS TO WEST MARTIS CREEK
AS DEVELOPED BY WATER QUALITY MODEL
SUSPENDED UNIT LOAD PERCENT
SEDIMENT TRIBUTARY (METRIC INCREASE
LOAD AREA TONS /KM2) ABOVE
srtllRfiK f METRIC /TONS') ("KILOMETERS ) YEAR BACKGROUND
	 WATER
Ski Area 59.96
Development 156 . 82
East Fork 19.62
Total W. Martis 236.40
ESTIMATED P REDEVELOPMENT
Total W. Martis 161.43
	 WATER
Ski Area .642
Development 11.89
East Fork 15.40
Total W. Martis 27.93
ESTIMATED PREDEVELOPMENT
Total W. Martis 19.29
YEAR 1975 - -
2.94 20.39 65 %
5.43 28.88 134 %
1.43 13.72 11 %
9.80A/ 24.12 95 %
CONDITIONS FOR WATER YEAR 1975
13. OS?-/ 12.34
YEAR 1976 	
2.94 0.22 -85 %
5.43 2.19 49 %
1.43 10.77 630 %
9.80^/ 2.85 94,,%
CONDITIONS FOR WATER YEAR 1976
13. 08^./ 1.47
A/ Total area above Gage No. 3 minus area above storage reservoir
B/ Total area above Gage No. 3 including area above storage reservoir
132

-------
 suspended sediment  loads  for  the  heavily  developed  portion of  the West
 Martis  Creek watershed  are estimated to be increased  134 percent  above
 predevelopment  levels.  The majority of this  increase comes from
 disturbed slopes, unrevegetated areas, concentrated runoff, and winter
 road sanding operations associated with the development.   Nonetheless, it
 must be realized  that the suspended  sediment  increase in West Martis
 Creek due to development  within the  watershed has not been excessive.

 As was  mentioned  in the section discussing benthic  macroinvertebrates,
 this doubling of  suspended sediment  load has  apparently  had minimal
 impact  on aquatic life in the stream.  It  is  likely that  those areas that
 are  producing higher than background  levels of sediment yield may be
 controlled in the future  by application of  additional  erosion and
 sediment  control  technology.

                          LONELY GULCH CREEK

 The  basic  equations correlating suspended sediment  concentration  (SS-mg/1)
 with  streamflow (Q-l/sec)  for the two streamflow gages on Lonely Gulch
 Creek are  listed in Table  VII-8.  Gage No.  5 monitored streamflow in
 Lonely  Gulch Creek  above  Rubicon Properties Subdivision, while Gage No. 6
 monitored  streamflow below the development.  The suspended  sediment
 versus  flow  relationship  for Gage No. 5 has been corrected  for any
 settling  that might occur  in the small reservoir just above Gage No. 5.
 Samples collected above the reservoir usually had 10 percent greater
 suspended  sediment  concentration than did samples collected just
 below the  reservoir.  The  significance levels computed for  the
 correlated suspended sediment versus flow relationships are less than
 those developed to represent conditions in West Martis Creek.  Any
 relationship between runoff, erosion, and sediment transport in
Lonely Gulch Creek is complicated  by:  (1) the comparatively small size
of the watershed,  (2) the extremely high  levels  of concentrated
erosion, (3)  the erratic deposition and resuspension of large sediment
particles depending  on  the local stream gradient and instantaneous
flow  rate, and (4) the  loss of streamflow  as percolating groundwater
in the lowest portions  of the watershed.   Although the correlation
of low flow suspended sediment levels at Gage  No.  6  is extremely poor
 (77.2 percent),  the  significance of low flow conditions in comparison
to rainfall and  snowmelt contribution is minor.   Similarly, even
though the significance  levels  of  rainfall and snowmelt (94.5 percent
                                 133

-------
                                TABLE VII-8

                     SUSPENDED SEDIMENT CORRELATIONS  FOR
                             LONELY CREEK GULCH
RUNOFF TIME
CONVERSION*
                                             DATA
                                            POINTS
                                           PERCENT
                                         SIGNIFICANCE
Gage No. 5  (above all development)

All Flow Types        SS=.043(Q)+0.85


Gage No. 6  (below all development)

Rainfall              SS=38.1(Q)-656.

All Snowmelt          SS=.853(Q)-14.5

Low Flow              SS=.024(Q)-1.29
                     70
>99.9
                      7

                     36

                     24
>94.5

>92.5

>77.2
* Note:  SS = Suspended Sediment Concentration (mg/1)
          Q = Streamflow (I/sec)
     and 92.5 percent) are slightly lower the 95 percent limit usually
     considered acceptable, their relationships are felt to be reasonable
     estimates of expected suspended sediment levels in Lonely Gulch Creek.

     Unfortunately, there is a complete lack of information on the level of
     suspended sediment and erosion rates in the Lonely Gulch Creek system
     prior to development.  This problem was circumvented by assuming that
     sediment yield per unit area monitored at Gage No. 5, above the entire
     development, would be considered representative of predevelopment
     conditions for the entire watershed.

     A graphical presentation of the suspended sediment concentration versus
     Streamflow relations at Gage No. 5 and Gage No. 6 is shown in Figure
     VII-13.  The below-development relationships are depicted by solid lines,
                                      134

-------
CC
LU
I-
LU
o
o
o
a
LU
C/3
LU
a
a.
CO
                          CORRELATION  OF
          SUSPENDED  SEDIMENT   CONCENTRATION
          WITH   STREAMFLOW  AT  GAUGES  #5 &  #6
     LONELY  GULCH  CREEK  (RUBICON  PROPERTIES)
                        GAUGE#6 RAINFALL
                                                .GAUGE* 6
                                                SNOW MELT
                           GAUGE # 5
                         ALL FLOW TYPES
                                   GAUGE #6
                                   LOW  FLOW
               20
40  60 80 100    200    400 600 800 1000
 STREAM FLOW  (LITERS/SEC.)
                                                             2000
                                             STATE  OF  CALIFORNIA
                                      STATE WATER RESOURCES CONTROL BOARD
                                             STREAMFLOW
                                           LONELY   GULCH
                                     DEMONSTRATION OF EROSION  AND
                                      SEDIMENT  CONTROL TECHNOLOSY
                                          FltURf NUMIEft

                                            VII-13
                                 135

-------
                                TABLE  VII-9

       SUSPENDED SEDIMENT  CONTRIBUTION TO LONELY  GULCH CREEK (RUBICON)
                           FOR VARIOUS FLOW  TYPES
  FLOW
  TYPE
% OF
TIME
                                 SUSPENDED SEDIMENT LOAD (METRIC TONS)
                                     FOR TOTAL PERIOD OF RECORD^7	
GAGE #5
                              GAGE #6
Low Flow

Rainfall

  lowmelt
 43
  3.37

  5.26

 11.33
16.8

26.4

56.8
  1.61

119.29

210.53
 0.5

36.0

63.5
                             19.96
                          100.0
                                                           331.43
                                                      100.0
A/ Period of record includes 27 months of data at Gage #5 and Gage #6 from
   November 1973  through October  1974 and June 1975  through August 1976
     whereas  the above-development  relationship  is  shown by  a  dashed line.
     A substantial  jump  in rainfall and snowmelt runoff  suspended sediment
      concentrations occurs between  Gage No.  5  (above development)  and Gage
     No.  6 (below development).

      The relative contribution of suspended  sediment load for  various flow
      types is presented  in Table VII-9.  As  was  true of  the  West Martis Creek
      system,  the majority of the suspended sediment load is  contributed during
      the winter months and peak spring snowmelt  period.   The most intense
      conbribution occurs during rainfall periods.  Although  only 3 percent  of
      the period of  record was during rainstorm events, fully 36 percent of
      suspended load monitored below the Rubicon Properties development
      occurred at these times.  A graphical presentation of the suspended
      sediment loads in Lonely Gulch Creek during the period of record is
      presented in Figure VII-14.  By comparing this graph to Figure VII-6,
      it is possible to see how suspended sediment loads are related to, and
      fluctuate with, various levels and types of streamflow within Lonely
      Gulch Creek.  Figure VII-14 demonstrates the vast increase in sediment
      load between Gages No. 5 and  6.
                                       136

-------

















1

>
          \
o
in
         (H1NOW/SN01)  QV01
                                  137

-------
                                TABLE VII-10

               SUSPENDED SEDIMENT LOADS TO LONELY GULCH CREEK
                     AS DEVELOPED BY WATER QUALITY MODEL
                     	 TOTAL PERIOD OF RECORD^/ 	
      SOURCE
    SUSPENDED
    SEDIMENT
      LOAD
rMRTRIC
                                    TRIBUTARY
                                      AREA
                                    CTCTT.OMETER2)
                UNIT          PERCENT
                LOAD          INCREASE
            (METRIC TONS/KM2)  ABOVE
               (  YEAR  )    BACKGROUND
 Upper Watershed

 Development

 Total Watershed
       8.129

     138.228

     147.357
2.37

0.38

2.75
  3.43

366

 53.6
10,600 %

 1,460 %
 A/  Period of  record includes  27 months  or  data  at  Gage  #5  and Gage #6  from
    November 1973  through  October  1974 and  June  1975  through August 1976
 B/  Upper watershed  values are assumed to be representative of background
 ~  levels for entire watershed
     A further  comparison  between background  and  development  suspended sediment
     yield conditions within the Lonely  Gulch Creek watershed is  given in Table
     VII-10.  As  shown,  the suspended sediment load per  unit  area jncreases
     from 3.43  ton/km2/year from the upper watershed  to  366 ton/km /year from
     the Rubicon  Properties development.  This is a 10,600 percent increase.
     The total  yield from  the entire watershed is increased 1,460 percent to
     53.6 tons/km2/year.  As was indicated by the results  of  the  benthic
     macroinvertebrate monitoring, this  massive sediment load to  Lonely Gulch
     Creek has  had a severe impact on the aquatic life of the stream.

F.   SUMMARY AND  CONCLUSIONS

     One of the most significant results of  the suspended sediment sampling
     program at Northstar  was that it enabled the project staff to determine
     the location and relative severity of erosion problems remaining after
     initial construction.  Clearly, the land disturbance created in the con-
     struction of Northstar was held to a minimum.  Due to conscientious
                                      138

-------
planning, development, and construction practices,  only  scattered
instances of detectable erosion problems still remain.   They are
discussed in Section V of this report and are listed as  follows:

     Problem 1.  Oversteepened and unrevegetated slopes  adjacent to
     parking lots and roadways.  This problem was mainly located near  the
     wastewater treatment plant, Northstar Drive, and the Village  Center.
     Eroded sediments from these locations discharge to  West Martis  Creek
     just above and below its confluence with the East Fork.   A
     substantial effort was made by the project staff to control erosion
     from these sources (see Appendix B).   The total oversteepened,
     unrevegetated slope area was less than 0.5 hectare.

     Problem 2.  Urban runoff from the Village Center commercial area.
     A large portion of the suspended sediment came from sources
     mentioned in Problem 1 above.   Nonetheless,  a  portion derived from
     dirt loosened from vehicular traffic in the Village Center area and
     from winter road sanding operations.

     Problem 3.  Uncontrolled drainage flowing over an artificially  filled
     and unrevegetated ski run.  The areal extent of this problem  was
     about 0.6 hectare near the Village Center.   This problem was  further
     compounded by disturbance caused by skiers and maintenance vehicles
     in the late spring when little snow cover remained.

     Problem 4.  Heavily traveled dirt road adjacent to  and crossing the
     East Fork of West Martis Creek.  The problem here was greatest  during
     spring snowmelt when continuous vehicular traffic would loosen  the
     roadbed, allowing it to be washed into the creek.

     Problem 5.  Remaining uncontrolled drainage and unrevegetated areas
     located near the base of the main ski bowl.

Clearly Problems 1 and 2 were the most significant  and the most difficult
to control, although occasional higher suspended sediment concentrations
were recorded elsewhere.

Urban runoff, combined with drainage from oversteepened  and unrevegetated
slopes near the Village Center, was the most frequent and readily
discernible source of sediment discharges  to West Martis Creek.  A large
part of the problem was due to a lack of adequate sediment retention
facilities for drainage from the Village Center commercial area.   A
planning recommendation made prior to the construction of Northstar's
Village Center anticipated that sediment retention  facilities would  be
required to meet water quality standards.   However,  such a sediment
catchment facility was not provided when the Village Center and its
drainage appurtenances were constructed.  Although  such  a catchment
                                 139

-------
devise was not added as part of this demonstration project, addition
of such a structure in the future, coupled with careful maintenance,
would substantially lower the sediment yield from the Village Center.

It must be emphasized, however, that although the construction and
development of Norths tar has led to a 100 percent increase in the amount
of sediment yield, the impact on aquatic life in West Martis Creek has
been negligible.  Although sampling stations for Benthic
macroinvertebrates were established to monitor areas in the Norths tar
development where siltation and erosion problems were suspected to occur,
the macrobenthic community suffered only minor perturbations.  The
majority of the remaining sediment transport and erosion problems within
the West Martis Creek watershed can be further reduced by further
revegetation and adequate drainage control.  As part of the erosion
control project, considerable emphasis was placed on revegetation of
disturbed areas and some minor drainage control (see Appendix B) .  By
implementation of these measures, it is believed that suspended sediment
transport from the the Northstar development has been further reduced.

Within the Lonely Gulch Creek watershed, on the other hand, it was
impossible to determine the relative significance of a number of
different sediment discharges from Rubicon Properties Subdivision.  All
discharges from culverts, ditches, and drainage swales had extremely high
levels of transported sediments.  While sediment discharge per unit area
of watershed above the development was estimated at 3.43 tons/sq km/year,
the average estimated discharge from the development was estimated to be
366 tons/sq km/year.  This represents a 10,600 percent increase above
estimated natural background levels.  A graphical comparison of
predevelopment and postdevelopment suspended sediment yields at the
Northstar and Rubicon Properties erosion control project sites is
depicted in Figure VII-15.  The difference is not only in suspended
sediment yield, but also the differing impact of suspended sediment
discharge between Northstar and Rubicon Properties is readily apparent.
An almost one-fold increase in sediment yield within the West Martis
watershed after development had negligible impact on the monitored
benthic macroinvertebrates.  Within Lonely Gulch Creek, however, total
numbers of macroinvertebrate individuals were reduced to as low as 1
percent of the density found upstream of suspended sediment discharges.
The average density of individuals downstream of discharges to Lonely
Gulch Creek during 1975 and 1976 was 32 percent of that found upstream.
Nunfcers of different families and diversities of the macroinvertebrate
populations were also substantially decreased.  Average diversity, a
measure of the overall "health" of an ecologic system, was lowered from
2.28 at an upstream station to 1.80 for downstream stations heavily
affected by suspended sediment scour and deposition.

While the development of Northstar-At-Tahoe has had a minimal and per-
haps acceptable impact upon West Martis Creek, the development of Rubicon
Properties has led to the totally unacceptable destruction of Lonely
Gulch Creek.
                                  140

-------
     3.5
 QC
 <
 UJ
 UJ
 oc
o
UJ
CO
2
O
9
QC
UJ
UJ
>-
UJ
^
o
UJ
CO

Q
UJ
O
z
UJ
Q.
CO

CO
3.0
     2.5
2.0
1.5
 1.0
0.5
h-

LJJ

Q.
O

UJ

LLJ
Q
          UJ
          CC
          Q_
                           CD
                           N-
                           CD

                           i
                               CD
UJ

Q.
O

UJ
>
UJ
Q
                CO
                O
                Q.
         NORTHSTAR  -  AT  -  TAHOE
                                       RUBICON  PROPERTIES
FIGURE 3DT-I5.  COMPARISON OF PREDEVELOPMENT  AND  POSTDEVELOPMENT
SUSPENDED SEDIMENT  YIELDS AT  NORTHSTAR AND  RUBICON  PROPERTIES
PROJECT  SITES.
                                141

-------
                                SECTION VIII

           BEST MANAGEMENT PRACTICES FOR EFFECTIVE EROSION CONTROL
A.   Introduction

     A primary objective of this report  is to provide timely information on
     the cost-effectiveness of erosion control methods which could be applied
     to erosion problems typically found in  the Tahoe-Sierra region of
     California.  Because of time, funding,  and site limitations, the
     California State Water Resources Control Board  (State Board) was unable
     to demonstrate all erosion control  techniques that, might conceivably be
     used in the environment of the Tahoe-Sierra.  With these limitations in
     mind, the project staff chose to implement and demonstrate those methods
     which:

          -    appeared to be the most cost-effective,
          —    appeared to be environmentally sound,
               the project staff could utilize to develop reliable cost-
               effectiveness data which  otherwise would not be available,
               emphasized source control, rather than treatment after the
               fact,
          -    emphasized revegetation,  and
          -    could be easily implemented using unskilled labor, or, if
               skilled workers and special equipment are required, could be
               •implemented with a low unit cost.

     In addition to the above criteria the erosion control project staff
     placed the most emphasis on those techniques which could be applied to
     very steep (2:1 or greater) cut and fill slopes (see Figure VIII-1).
     Very steep slopes are common throughout the Tahoe-Sierra region where
     extensive past construction activities have been relatively unregulated.
     Not  only do they represent the greatest erosion problem and source of
     waste sediments transported to the streams  and lakes of the region, but
     they are also the most expensive and difficult problems to  control.  In
     addition,  those techniques which are applicable to very difficult steep
     slopes are generally appropriate methods for controlling erosion prob-
     lems on  less severe sites.   Several other documents published by the
     Environmental Protection Agency  (41, 42, 43,  44)  provide a  general, and
     in some  cases quite specific, discussion of the broad spectrum of erosion
     and  sediment control  technology currently available.   These documents
     should be  consulted for  further information on techniques not covered
     by this  project or not included in this report.  No  attempt has been made
     to reproduce information which is  adequately discussed elsewhere.
                                      142

-------
    Figure VIII-1.  Steeply eroding cut slope adjacent to paved
  roadway at the Rubicon Properties erosion control project site.
The erosion control methods discussed in this report are subdivided into
the following categories.

1.   Temporary Slltation Cpiitrol -  Includes  filter berms, filter fences,
     straw bale sediment barriers and impervious berms.  These methods
     are used for temporarily controlling siltation from on-going con-
     struction activities and short-lived disturbances  (less than 1/2
     year).  It is fully anticipated when using temporary siltation con-
     trol methods that they will be replaced by other permanent methods
     within 1/2 year.

2.   Drainage Control  - Includes berms,  dikes and gutters, drop inlets,
     rock lined channels,  water bars,  diversion dikes, percolation
     trenches and sediment retention basins.  These methods are used to
     control storm drainage and prevent  overland flow from eroding dis-
     turbed soil surfaces or other  highly erodible areas.

3.   Mechanical Stabilization of Oversteepened Slopes - Includes curbs,
     dikes, benches, breast walls,  retaining structures, slope scaling,
     overhang removal, and contour  wattling.  These methods are used to
     prepare and stabilize oversteepened slopes to a degree sufficient
     for the establishment of vegetation.

4.   Permanent Vegetative Erosion Control -  Includes willow staking,
     seeding, planting, mulching, fertilization, and irrigation.  These
     methods are viewed as the most appropriate means of stabilizing
     disturbed areas.   If used alone,  vegetative erosion control methods
                                143

-------
          can be expected to  achieve a considerable degree of success on less
          severe slopes (less than 2:1) where drainage control is not a prob-
          lem.  However,  on steeper slopes  (greater than 2:1) or areas with
          drainage problems,  permanent vegetative erosion control methods
          must be combined with drainage control and mechanical stabilization
          techniques.

B.   Cost Estimating Procedures'

     The equivalent costs of  erosion control methods used as part of the
     Erosion Control Demonstration Project  are  developed from actual material,
     equipment and labor requirements at the project sites, except when other-
     wise noted.  The following assumptions were used in developing the
     equivalent cost estimates presented herein, and are presumed to be
     representative of conditions found in  the  Tahoe-Sierra region of
     California.

     1.   Adverse climatic conditions,  such as  storms or high winds, are
          considered not to cause hindrances or delays in the installation
          of  the erosion control methods.

     2.   Except as otherwise specifically  noted, wages and  equipment  costs
          are based upon data published by  CalTrans  (45) as  of  June 30, 1976,
          plus an additional 10 percent allowance for profit.

     3.   Except as otherwise specifically  noted,  total labor costs are
          assumed to be $16.25 per hour,  including wage  (10.75/hr), social
          security  C6%), workmen's compensation insurance  (10%), unemployment
          insurance C5%), and an additional 25 percent  to  cover overhead,
          supervision  and profit.  For comparative purposes, labor costs
          including overhead and supervision,  for county workers and  unskilled
          conservation corps workers are assumed to  be  $10.00/hr and  $5.00/hr,
          respectively.  Much of the erosion control work described herein
          is  very labor intensive.  Where possible,  for each erosion control
          method, the  percentage of the total cost attributable to labor
          costs  at  $16.25 per hour is identified.  If different unit labor
          costs  are expected, overall cost  estimates should be revised
          accordingly.

      4.   All mulching and seeding techniques requiring hydromulching or
          straw blowing  equipment are assumed to be conducted by competitive
          commercial  enterprises.  Labor and equipment costs for hydromulch-
          ing and machine straw mulching are derived from CalTrans "mulch-
          in-place" contract figures for the first half of 1976.  It is
          assumed that the CalTrans contract amounts include direct and
          indirect labor and equipment costs, insurance, overhead,  supervi-
          sion, and profit.   Materials costs are considered separately.

      5.   Except as otherwise specifically noted, all materials costs are
           equivalent  to retail costs quoted by the various manufacturers,
           distributers or suppliers of materials used at the project sites
                                      144

-------
c.
      including estimated shipping costs  as  of  June 30, 1976.  Storage
      costs are not included.

 6.   Except as otherwise specifically noted, the person-hours assumed
      to be required to complete a particular task  are based upon the
      observed county and conservation corps person-hours required to
      perform the task at the  Erosion Control Project demonstration
      sites.  Although erosion control labor costs  are based upon commer-
      cial wage scales,  no allowance for  increased  work efficiency has
      been included in the cost analysis.  This was justified because, in
      several instances,  observed installation times using county person-
      nel and unskilled workers were less than or equivalent to manufac-
      turers estimates or estimates by others based upon the use of
      skilled or semi-skilled  labor.  In one case a gabion manufacturer
      estimated that labor requirements for  gabion  installation varied
      from 2.0 to 2.6 person-hours per cubic meter  of gabions filled.
      Experience at the project sites indicated that gabion installation
      required about 2.17 person-hours per cubic meter of gabions filled.
      In another case, a  report C46) describing willow wattling installa-
      tion and cost indicated  that a semi-professional 7-man crew could
      install wattling at about 2.70 meters per hour.  Unskilled workers
      at the erosion control project site were able to install wattling
      at a site of  about  3 meters per hour.  Thus,  using these two cases
      as indicators of work crew efficiency it is assumed that, for the
      type of work  involved, there are not significant differences in
      efficiency between  unskilled and skilled landscape laborers.

 7.    The equipment-hours, other than for hydromulching and straw
      blowing,  are based  upon the needs of a 5-person work crew assigned
      to a particular erosion control task.

 8.    As  a basis for cost estimates, the minimum land area requiring ero-
      sion control work is considered to be one  hectare.   It is assumed
      that this  is a large enough area to  attract substantial  competitive
      bidding  for a .contract to perform the erosion control  tasks.  Labor
      and equipment transportation, start  up, and shut down  costs  are
      considered to be negligible.

9.    Maintenance costs are not included;  once the initial erosion con-
      trol work has been completed, such costs are considered  to be
      nominal.

10.   Design costs are not included in these  cost estimates.

Temporary Sedimentation Control

Methods described in this section are intended only for temporary con-
crol of erosion problems, not  for long term  or permanent erosion control.
Situations when temporary sedimentation control methods are used include:
                                     145

-------
     -    on-going construction activities
     —    emergency situations
          post-construction periods until permanent control methods are
          firmly established.

Temporary sedimentation control does not necessarily prevent localized
erosion.  Its basic purpose in  and around the Lake Tahoe Basin is to
prevent erodible materials from being  transported to surface waters.
The Regional Water Quality Control Board requires that eroded earthen
materials must be contained within the construction site or property
boundaries.  Measures must be taken  to prevent off-site transport by
vehicles, wind and water.

1.   Control of Sediment Transport Directly Due  to Vehicular Traffic -
     The main concern is with the transport of earthen material off of
     the property by construction vehicles.  Control measures include:

          Well defined access drives to the project, limited to as few
          as possible.
a.
     b.   A clean base material, such as granitic gravel,  on all access
          drives.  Volcanic "cinders" are not considered to be "clean",
          since they have a large percentage of fine particles, and
          larger particles tend to break down when subjected to loads.
          Cinders should not be used in any application where there are
          no down-gradient sedimentation control facilities.

     c.   Equipment having a significant amount of mud, etc. attached
          to it should be washed before leaving the property.

 2.   Control of Sediment Transport Due to Wind - Limiting  the area of^
     soil disturbance as much as possible by holding equipment operating
     areas to a minimum is the best preventative measure.   Other measures
     include wetting problem surfaces or covering them with plastic
     sheeting, gravel, mulch, fiber netting, asphalt emulsion, or plastic
     emulsion.

 3.   Control of Sediment Transport Due to Water Flow - Water  flow stem-
     ming directly from human activities such as washing,  surface wetting
     and irrigation, can and should be limited.  Special measures must
     be employed  to control storm and snowmelt runoff and thereby pre-
     vent sediment transport.

 The Lake Tahoe Basin and vicinity is subject to heavy snowfall during
 the winter months, and, in most cases, extensive construction activities
 during this period are not practical.  Furthermore, local regulatory
 agencies do not  allow earth disturbing activities between October 15 and^
 May 1  of the following year and require  that all projects be "winterized"
 by October 15 of  each year.  "Winterization" means  complete installation
 of all necessary1 temporary and/or permanent erosion and sediment control
 facilities.
                                 146

-------
 Ideally,  temporary sedimentation control facilities should be designed
 to withstand tributary runoff flows due to a storm of a given recurrence
 interval.  For design purposes, the Regional Water Quality Control Board
 (Regional Board) uses a 20-year, 1-hour storm as the critical design
 storm.  The  Regional Board recommends use of the SCS triangular hydro-
 graph method for determining tributary runoff from a specific site during
 the design storm.  This method is further discussed under infiltration
 trench design.

                       1.  Impermeable Berm

 An impermeable berm is generally constructed by forming an earthen dike,
 covering the dike with impermeable plastic sheeting,  and placing clean
 gravel on the lower edges of the plastic as shown in Figure VIII-2 (see
 Section A-A), or burying the edges to a depth of about  10 centimeters.
 A   storage dike" (see Figure VIII-2,  Case A)  should be  positioned at the
 down gradient end of the disturbed soils area such that all flows from
 the project  site are retained by it.   Diversion dikes,  as shown below
 point  C", may be necessary.   The storage should be extended uphill a
 distance »L' as identified in Figure  VIII-2,  Case A,  to maximize storage
 capacity.

 The height of the down-gradient perimeter of  the storage  dike should be
based on storage requirements determined by an estimation of maximum
 runoff flow to the berm in a  20-year,  1-hour  design storm.  To decrease
 runoff to the storage dike, a diversion dike  may be used  to divert run-
off above a disturbed area (Figure VIII-2,  Case B).   Care must be taken
in the design and placement of diversion facilities to prevent erosion
on adjacent areas due to  channelization of  flow and discharge.  Figure
VIII-3 depicts a  typical  impervious berm installation.

As a minimum, the following design criteria should be included in speci-
fications for the construction of  impervious  berms:
     a.


     b.


     c.

     d.


     e.


     f.
the berm shall be constructed of available earthen material
mounded to a height of at least .33 meter,

the sides of the berm shall Be laid back to a  slope of no
greater than 1.5:1,

the surface of the berm shall be free of rocks or protrusions,

translucent plastic sheeting with a thickness not less than 6
mil shall be placed over the earthen berm,

the outside edges of the plastic sheeting shall be covered
with clean gravel or buried to a depth of 10 centimeters,

the dike shall be frequently inspected and repaired if
necessary,  and
                               147

-------
148

-------
    Figure VIII-3.  Impervious berm installation adjacent to  a
    stream channel at the Northstar erosion control project site.
     g.   the impervious berm shall be removed once permanent erosion
          and drainage control measures have been completed and are
          established.

                 2.  'Straw'Bale'Sediment Barriers

A straw bale sediment barrier is  generally constructed by laying bound
straw bales to form a wall or barrier.   The function of a straw bale
sediment barrier differs from an  impervious berm in that it is designed
to pass water while filtering and blocking transported sediments.  Straw
bale sediment barriers are useful not only in constructing extensive
barriers for the prevention of sediment transport from construction
sites but also in preventing transported sediment from being discharged
to specific points, such as  drop  inlets.   Figure VIII-4 depicts a typical
erosion problem discharging to a  drop inlet.   Figure VIII-5 depicts a
straw bale sediment barrier designed to prevent such a discharge.  Once
the problem is corrected at  its source, the straw bales should be removed.
Since straw bales eventually decompose, they  should be replaced or
removed prior to such an occurrence.   Installed straw bale sediment bar-
riers must be inspected frequently to be sure that  their structural
integrity is maintained and that  Joose  straw  is. not being washed into
drainage systems.  When mixed with mud  and water, loose straw forms a
sticky mass which can easily clog culverts, drop inlets, or other drain-
age strutures.

An added benefit of straw bale sediment barriers is  once construction
activities have halted,  and  permanent erosion control measures are
                                149

-------
Figure VIII-4.  Eroded soil material discharging to drop inlet.
    Irt
       Figure VIII-5.  Straw bale sediment barrier used to
           control problem pictured in Figure VIII-4.
                               150

-------
      TIGHTLY ABUTTED
      STRAW BALES
                                            EMBEDDED  TO A
                                            DEPTH OF  10 cm.
              STRAW  BALE  SEDIMENT  BARRIER
Figure VIII-6.  Typical straw bale sediment barrier installation design.
   established the straw bales may be used as a mulch to aid in the estab-
   lishment of vegetation on the disturbed landscape.  Because of the straw
   bales' exposure to the elements, it is unlikely that the straw could be
   applied in a mechanical mulching operation.  However, the "weathered"
   straw mulch may still be readily applied by hand.

   A typical straw bale sediment barrier installation is depicted in Figure
   VIII-6.  As a minimum, the following design criteria should be included
   in the specifications for the construction of straw bale sediment
   barriers:
       a.
       b.
       c.
       d.
straw bales shall be placed in a row on the contour with ends
tightly abutting adjacent bales,

each bale shall be embedded in the soil to a minimum depth of
10 centimeters,

the straw bale sediment barrier shall be inspected frequently
and repaired if necessary, and

the straw bales shall be removed once permanent erosion and
drainage control measures have been completed and are
established.
                                 151

-------
Surface contact between the straw bales and the ground surface is some-
times a problem, particularly if the bales are insufficiently embedded.
Portions of broken bales placed beneath the barrier will assure contact
and provide more complete filtration.  An optional added specification
could also provide for the anchoring of the straw bales by means of
re-bar or stakes.  Such a specification would be required if the barrier
were potentially subject to high flows or other stress.

                        3.  Filter Berms

A filter berm is constructed in the same manner as an impervious berm
with the exception that the berm is constructed of material designed to
permit the passage of water, and at the same time filtering transported
sediments.  Filter berms do not require the extensive storage areas
required by impervious berms.  They eventually become clogged with the
sediments they are designed to remove.  Frequent inspection and contin-
ued maintenance of a filter berm installation is required to insure
satisfactory performance.  Maintenance may involve simple cleaning of
the filter berms, or, in some instances, require complete replacement
of sections of the berm.

Adequate filtration by a filter berm is based on proper pore size in the
filtration media.  For example, gravel filters will not provide adequate
filtration of most suspended sediment material.  Two typical designs for
acceptable filter berms are shown in Figure VIII-7.  At a minimum the
following design criteria should be included in the specifications.
  CLEAN GRAVEL
  OVER  CLEAN
  SAND  CORE
                                             PERVIOUS
                                    SAND CORE FILTER BERM
   FILTER  FABRIC  OVER
   CLEAN  GRAVEL
   BURY FABRIC
   ENDS TO DEPTH
   OF 10 cm
      PERVIOUS
FILTER FABRIC BERM
 Figure VIII-7,  Typical pervious  filter berm installation designs.

                                152

-------
 For the construction of  a sand core filter berm:

      a.   the sand core  filter berm shall be constructed of coarse clean
           sand with not  more than 5 percent (by weight)  of the particles
           less than .06  mm in diameter,

      b.   the sand core  shall be mounded to a height of  not less than 30
           centimeters,

      c.   the sides of the sand core shall be at a slope of not greater
           than 1.5:1,

      d.   the sides of the sand core shall be covered with clean gravel
           to  a depth of not less than 10 centimeters, and
      e.
          not more than 5 percent  (by weight) of the gravel shall have
          diameters larger  than 5  centimeters, or less than 1
          centimeter.

For the construction of a filter fabric berm:

     a.   the filter fabric berm shall be constructed using a core of
          clean gravel  with not more than 5 percent (by weight) of the
          gravel having diameters not larger than 5 centimeters,  nor
          less than 1 centimeter,

     b.   the gravel core shall be mounded to a height of not less than
          30 centimeters,

     c.   the sides  of  the  sand core shall be at a slope of not greater
          than 1.5:1,

     d.   the gravel core shall be free of any protrusions,

     e.   over the gravel core shall be placed filter fabric material,

     f .   the outer  edges of the filter fabric shall  be buried at the
          base of the gravel core to a  depth of 10 centimeters, and
    g.
          clean gravel  shall be placed to a depth of not less  than 10
          centimeters along the inside and outside base of the berm.

For both the sand core  and filter fabric berms, the following  specifi-
cations should be included:

          the filter berm shall be inspected frequently and repaired if
          necessary, and
          the filter berm shall be removed once permanent erosion and
          drainage control measures have been completed.
                               153

-------
                        4.  Filter Fences

Filter fences control controlling siltation in the same manner as  filter
berms.  Filter fences are particularly advantageous where space is
limited.  Impermeable dikes, straw bale sediment barriers, and filter
berms can require up to 2-meter wide strips for their construction
F?Serfences, on the other hand, can be placed in less than  5 meter
strips around a disturbed site.  Figure VIII-8 depicts a typical filter
fence installation designed to protect a stream from siltation generated
by the construction of an adjacent  golf course.

A diagram showing a typical filter  fence installation procedu^ is Pre-
sented in Figure VIII-9. At a minimum, the following design "iterxa
should be included in the specifications for  the  construction of filter
fences:

          the fence shall be constructed of cross woven welded wire
          fence material with openings  not greater  than 10  cm x 10 cm,

      b    the welded wire fencing shall be securely attached  to fence
          posts  firmly planted in the ground at spacings  not  greater
          than 3 meters,

      c   the fence posts shall be located on the down slope  side of the
       *   fence  and extend at least .5 meter above the ground surface,

      d.   the welded wire  fencing shall be tensioned between  fence posts,

          pervious filter  fabric shall be placed on the up slope side  of
           the fence with a portion folded over the fence top  and with  at
           least .25 meter  remaining at the toe which will be  buried,

           the filter fabric shall be attached in such a manner as not to
           rend or tear the fabric,
a.
 e.



 f.


 g.


 h.


 i.
       k.
on the up slope side of  the fencing, the foot of the fabric
shall be buried to  a depth of not less than .25 meter,

replaced soil shall be firmly tamped after the filter fabric
foot has been placed,

all operations involving the construction of the filter fence
shall be conducted so  as not to tear or otherwise increase the
porosity of the filter fabric,

once constructed, the filter fence shall be frequently
inspected and repaired if necessary, and

the filter fence shall be removed once permanent erosion and
drainage control measures have been completed.
                                  154

-------
Figure VIII-8.  Filter fence installation adjacent to a stream
    channel at the Northstar erosion control project site.
             DRAPE FILTER  FABRIC
             OVER FENCE AND FASTEN
             WITH TIE  WIRES
                                             AFFIX  WELDED
                                             WIRE  FENCING
                                             TO  POSTS
                                FILTER FABRIC FENCE
                        PLACE  FENCE
                        POSTS  ON  CONTOUR
BURY TOE OF
FILTER  FABRIC
IN  TRENCH ON
UP SLOPE SIDE
   Figure VIII-9.   Typical filter fence installation design.
                            155

-------
   5.  Comparative Costs of Temporary Siltatibri Control Methods

The cost of constructing temporary siltation control facilities may vary
widely depending on availability of materials and type of construction
sites, including the space available for  siltation control facilities.

Table VIII-1 lists the equivalent cost  of the various types of siltation
control facilities constructed at Northstar erosion control project
site.  Cost estimates are based on assumptions listed earlier in this
section and include one-time installation costs only.

Although the above costs are only estimates, it is possible to say that
the filter berms and fences are roughly twice as costly as a simple
impervious earthen berm.  On the other  hand, an impervious berm requires
a considerable amount of water storage  space behind the berm to effec-
tively settle suspended sediments.  The cost of committing such space is
not reflected in these estimates.

The straw bale sediment barrier (intermediate  expense) has the added
advantage that the materials may be reused as mulch.   The filter fence
also has the advantage that its materials may  be  reused.  These savings
are not reflected in the above- cost estimates.  Although  filter fences
have received little use in the Tahoe-Sierra area,  it does appear  that
their expense and effectiveness are highly competitive with other  tempo-
rary sedimentation control devices.


TABLE VIH-1
TEMPORARY SILTATION

'CONTROL


EQUIVALENT INSTALLATION 'COSTS
,.
Impervious Earthen
Berm (30 cm high)
Straw Bale Sediment
Barrier
Sand Core Filter
Berm (30 cm high)
Filter Fabric
Berm (30 cm high)
Filter Fabric
Fence (50 cm high)

MATERIALS
.30
1.80

4.33

4.00

2.00

UNIT 'COSTS ($/METER)
EQUIPMENT LABOR
1.18 1.60
	 2.71

1.18 1.60

1.18 1.60

1.18 3.88


TOTAL
3.08
4.51

7.11

6.78

7.06

                                  156

-------
D.   Drainage Control

     When considering methods  required for the effective control of erosion
     and sedimentation,  adequate control and drainage of storm waters is of
     primary importance.   It makes little sense to commit a large effort to
     the establishment of  permanent erosion control by means of revegetation
     if storm waters  are allowed to wash everything away.  Uncontrolled runoff
     from impervious  surfaces  can easily cause significant erosion problems
     even if the majority  of an erosion control project site is adequately
     revegetated  Not only will uncontrolled storm runoff generate localized
     erosion in  drainage swales and channels on the construction site,  but  it
     will also cause  further erosion problems elsewhere if allowed to dis-
     charge  to natural channels and streams which are not large enough  to
     handle  excessive storm water flows.   These off-site erosion problems
            man±      ±n the f0rm °f increased streambank erosion and channel
    Effective drainage control is based on two principles:

    1.   all concentrated runoff should be carried in non-erodible ditches
         and swales,

    2.   when possible, all storm runoff from impervious surfaces must be
         infiltrated with no direct discharge to surface waters.

    If these two principles are universally applied, in conjunction with
    effective revegetation of disturbed areas,  erosion problems will be
    significantly reduced,  if not eliminated.   In  all future construction
    in the Tahoe-Sierra region these two basic  tenets must be adhered to.

    The application of this drainage control approach to past construction
    sites may be difficult.   In many cases  the amount of im^rvious surface
    coverage vastly exceeds  the capacity of remaining pervious areas to
    percolate storm runoff.   In other instances, there is not sufficient
    space for^ the installation of  runoff interception works or percolation
    trenches due to the close proximity of impervious surfaces to stream
    zones or due to intervening steep or difficult terrain.

    The Rubicon  Properties erosion control project site is  in an area where
    all these difficulties are  encountered.  Totally effective drainage
    control  at such a site would be very expensive.  In locations such  as
    Rubicon  Properties where effective percolation of storm drainage  is
    prohibitively expensive or impossible, the erosion control program  must
    concentrate heavily upon stabilization of disturbed slopes and construe-'
    tion  of  non-erodible drainage swales.  If transport  of  sediment to  surface
    waters remains  a major problem, sediment retention basins  would then be
    required to further reduce the sediment load.   A small  sediment retention
    basin can be quite effective in reducing sediment load  during storms,
    but would not be effective as a percolation pond to  substantially limit
    peak  storm water flows from impervious  surfaces.
                                  157

-------
This section on drainage control  is not intended to be a design handbook
for drainage control structures.  For  the appropriate design and sizing
of particular drainage control structures, a registered civil engineer
should be consulted.  Various publications by the EPA (41, 42, 43) offer
details on the design and layout  of several drainage control facilities
not discussed in this report including:  check dams, chutes and flumes,
erosion checks, Fabriform  Erosion Control Mats, flexible downdrains,
and level spreaders.  The project staff did not feel they would be
effective within the project sites, or in the surrounding vicinity.
Drainage control methods and structures which are mentioned are xncluded
because:

          they are fundamental to effective drainage/erosion control,
          they are or have been frequently omitted  from projects  in the
          Tahoe-Sierra region of California,
          their effectiveness has been demonstrated or  observed within
          the project sites and/or surrounding  vicinity.

                   1.  Curbs, Dikes and Gutters
 Curbs,  dikes  and gutters are
 (Mechanical Stabilization of
 a slope toe bench.  They are
 able surfaces to appropriate
 lined ditches, or a properly
more fully discussed in the next section
Oversteepened Slopes) as a means to provide
also used to direct runoff away from  erod-
discharge points such as drop inlets,  rock-
sized percolation facility.
 Figure VIII-10 shows  the gully formation that occurred when street drain-
 age was allowed to  flow uncontrolled down an unstable fill slope.   During
 a 15-year period it is  estimated that at least 1,800 metric tons were
 eroded from the slope.

 Proper maintenance of curbs,  dikes  and gutters is essential.  Figure
 VIII-11 shows the result of a breach in a dike at Rubicon Properties.
 Over one hundred metric tons  of soil were removed from this unstable
 fill slope in one snow  melt season.

                          '2.  Drop  Inlets

 The usual purpose of a  drop inlet  (D.I.) structure is to collect and
 direct, via underground conveyance, storm water  runoff to an appropriate
 discharge point.  An important  addition  to  drop  inlet design CSee Figure
 VIII-12) is provision for settling and retention of  suspended sediments.
 Actual sizing for such a structure is  dependent  upon:

           size of runoff area tributary  to  the drop  inlet,
           expected suspended sediment load  to the drop inlet,
       -    frequency of runoff conditions, and
           expected frequency of maintenance.

 Design and spacing of such structures should be  conducted by a  registered
  civil engineer.  Effluent from the drop  inlet should be  directed  to  non-
  erodible conveyance  facilities and infiltration structures. A  good  rule
                                  158

-------
Figure VIII-10.   Gully erosion on fill slope at the^^ RuMcon™Properties
erosion control  project site resulting from poor drainage control,  and
                         lack of vegetation.
 Figure VIII-11.  Severe erosion on fill slope at Rubicon Properties
   erosion control project site caused by a break in an A-C dike.
                                 159

-------
                                 REMOVEABLE
                                 GRATE
   FLOW
                                                   N\NN \\-\N
                                                  TO  INFILTRATION
ALLOW  ACCESS
FOR  EASY   -Vv
CLEANING    XX
                                                      CONCRETE
                                                      OR CMP
Figure VIII-12.
                  Typical drop inlet installation designed to settle
                   and trap transported sediments.
of thumb would be to design drop inlet structures to settle and remove
90 percent of anticipated suspended sediments at design flow conditions.

If oil and grease in the storm runoff is expected to cause additional
problems, "T" type entrance to the effluent line must be provided.  This
will effectively block oil, grease and other low density contaminants
from being discharged to surface water or subsequent infiltration
facilities.

The effectiveness of drop inlet structures designed to settle suspended
sediments will quickly diminish if they are not adequately maintained.
This is particularly true if  the drop inlet collects runoff from eroding
surfaces.

                       3.  Drairiage  Channels

If the collected runoff must be directed overland to an appropriate dis-
charge point, the use of rocklined  (or similar) drainage channels is
recommended.  The reasons for this are:

     -     aesthetic natural appeal,
     -     non-erodible surface,
                                160

-------
          low cost, and
          high surface "roughness" which dissipates  the erosive energy
          of the flowing water.

The last factor, that is energy reduction of the flowing water, can be
further enhanced by drop structures or energy dissipators.

Use of rock-lined channels is limited to gentle  slopes.  For steeper
slopes other methods such as sectional downdrains, or culverts, as
pictured in Figure VIII-13, must be used.  Figure VIII-14 depicts the
type of problem that can arise if collected  drainage waters are allowed
to flow uncontrolled over an erodible surface.  Approximately 20 metric
tons of soil were eroded in a single snow melt season at this site.
Figure VIII-15 depicts a rock lined channel which was designed:and
installed to correct this problem.

Costs of rock lined channels are dependent upon size, equipment access,
and availability of rock material.   The  rock channel pictured in Figure
VIII-15, which is approximately 30  cm deep, 100 cm wide, 100 meters  long,
located in a readily accessible area,  and constructed of readily avail-
able stone from adjacent areas,  would cost $12.36 per meter based upon
the assumptions  listed at the beginning  of this section.  If rocks had
to be -purchased  and transported to  the site the cost would be expected
to increase by an additional $1.75 per meter.
 Figure VIII-13,  Corrugated metal pipe used to direct drainage
               across highly erodible fill slope.

                               161

-------
                                                         to
                                                     £>•> to

                                                         }-i
                                                     T3  O
                                                     0)  rt   •
                                                     tO      Ctf
                                                     3  60 -l «H
                                                      60  O
                                                      •H  O
                                                      Br_t  J3J
162

-------
 If only infrequent very low flows are directed to overland channels on
 very gentle slopes, an alternative to rock lining may simply be channel
 vegetation.  Vegetative techniques are'described in a subsequent section
 entitled "Permanent Vegetative Erosion Control".  Methods which are
 applicable for vegetating small channels include:

           willow staking,
      -    contour wattling,
           •seeding with mulch nets and blankets, and
          -seeding with fiberglass roving.

                          4.  Water Bars

 Water bars can be effectively employed to prevent storm runoff  from
 developing and accumulating eroded sediment on heavily travelled or aban-
 doned dirt roads and trails.  By breaking up an extended erodible surface
 into a series  of smaller areas with separate drainages,  storm runoff
 flow velocities and quantities can be significantly reduced.  Figure
 VIII-16 depicts a typical water bar installation on a heavily travelled
 dirt road  at the Northstar erosion control project site.   Prior to  instal-
 lation of  the  pictured water bar, road drainage resulting from  snow melt
 and rainfall flowed down the road and discharged directly to  a  stream
 which passed under the road at a low spot.   Heavy vehicle traffic pulver-
 ized the road  surface resulting in a sediment-laden discharge to  the
Figure VIII-16.   Water bar installation on heavily travelled dirt
                        road at Northstar.
                                163

-------
stream.  After construction of the water bar pictured in Figure VIII-16,
road drainage was diverted to a densely vegetated area which effectively
intercepted and filtered the drainage water prior to dishcarge to the
stream.

Good judgement must be used in the design and location of water bars.
Figure VtlI-17 depicts an extremely  close spacing of large water bars on
an abandoned dirt road at the Rubicon Properties erosion control project
site.  Prior to the installation  of  the pictured water bars, erosion from
this dirt road was extreme.  Furthermore, accumulated runoff had caused
increased erosion down gradient from the road.  Not only will such large
water bars or similar barriers act to divert surface drainage to more
stable areas, but they will also  discourage further vehicular use of the
road which could disrupt revegetation measures.  As a guide, Figure
VIII-18 may be used to determine  the maximum spacing for water bars for
various slope gradients and soil  erosion hazard ratings.  The data shown
in Figure VIII-18 is based upon information prepared for use by the
U. S.  Forest Service  CIS,  47).   Erosion hazard rating  is based upon the
area 'below the road or tract.

In addition  to proper spacing as  indicated in Figure VIII-18, water bars
should discharge into undisturbed areas,  rock ground, or areas well
protected with vegetative cover.   Water bars  should also be located  to
accept and redirect runoff from lateral disturbed areas or  other  trib-
utary areas.
                       ~
  Figure VIII^17»  Closely spaced water tars on abandoned dirt road.
                                 164

-------
                     5.  Infiltration Trenches

The best approach to reducing erosion generated by storm runoff is  to
percolate drainage from all impervious surfaces.  In most instances
impervious surface runoff cannot be discharged to surrounding undis-
turbed areas for percolation without causing substantial erosion problems
The Regional Water Quality Control Board, Lahontan Region,  requires an
adequately designed percolation trench for runoff control in  the California
portion of the Lake Tahoe basin.  Figure VIII-19 depicts a  typical cross
section design for an infiltration trench.   In addition to  the configura-
tion depicted in Figure VIII-19, a well designed infiltration trench
will also have a provision for overflow to  a storm water system in the
case of:

1.   failure of the infiltration trench due to clogging by  deposited
     sediments, or

2.   storm intensities  greater than the "design storm".
     80
                                           MEDIUM (moderate)
                                           LOW (slight)
                       20       30      40
                         SLOPE GRADIENT (%)
  Figure VI1I-18.  Maximum water bar spacing for various slope
              gradients and erosion hazard ratings.
                              165

-------
HEADERS  ANCHORED
BY ROCK  BACKFILL
AND  CRADLE
  5 x 15 cm. HEADER
                                               CRADLES SPACED
                                               AT INTERVALS  AS
                                           ivy DETERMINED  BY
                                            ^ ENGINEER.
Figure VIII-19.   Typical infiltration trench design for percolation
             of  storm runoff from impervious surfaces.
Infiltration trench life expectancy can be vastly increased by the use
of sediment traps to remove suspended sediments before discharge to  the
trench.  However, drop inlets or  similar structures placed as an inter-
mediate treatment device between  the impervious surface and the xnfxl-
tration trenches cannot be expected to be totally effective in removing
all sediment from the storm runoff.  Thus, any infiltration trench xn-
stallation should provide for removal of the rock backfill and accumu-
lated sediment depositions. The  removed rock backfill can be washed and
reused or replaced with new rock. If oil and grease deposits, whxch
could clog and reduce trench effectiveness are anticipated, adequate
attention must be given to the  separation of such substances from the
runoff prior to discharge to the trench.

The final design of infiltration trenches and other appurtenances should
be left  to a professional engineer.   The Regional Water Quality Control
Board, Lahontan Region, uses the following relationship as a guideline
for the  sizing of infiltration trenches (48):
                                 166

-------
f
               L  =    	A-Q	
                      [(W-P) +  .67  (D'P)] + [.33 0>W)1
                                             (Equation VIII-1)
              where:    A =
    area of impervious surface contributing runoff to
    infiltration trench (square meters)
L = length of the trench (meters)
W = width of the trench (meters)
D = depth of the trench (meters)
P = percolation rate of the soil  in which the trench is placed
    (cm/hr)
T = storm duration (hours)
Q = unit runoff from impervious surface  area  (cm).  The value
    of Q is determined by using the SCS  triangular hydrograph
    method (49, 50, 51) as  follows:
                           Q =
                               (R - I + S)
                                             (Equation VIII-2)
                         R =  depth of rainfall (cm)
                         I =  initial abstraction which is the maximum amount of rain-
                             fall that can be absorbed on the impervious surface with-
                             out producing runoff.  It is empirically assumed that
                             I = 0.25 (cm).
                         S =  maximum potential difference between R and Q, accounting
                             for minor permeability of an impervious surface.  S = .508
                             (cm) for precipitation ranging from 0 to 30.5 centimeters.

               The reasons that the SCS method was chosen over the somewhat simpler
               rational method include:

               1.    it is still simple and relatively straightforward,

               2.    it is based upon a "triangular hydrograph" and therefore acknowl-
                    edges the variation in runoff rates during a typical storm,

               3.    it accounts for surface retention (surface wetting) or "initial
                    abstraction" which the rational method does not consider.

               The Regional Water Quality Control Board, Lahontan Region, requires
               infiltration trenches on new projects in the Tahoe area to have a 95
               percent reliability.  Therefore, infiltration trenches are designed
               such that  the  probability of overtopping is no more than five percent.
               Since the  probability of an event being equalled or exceeded at any time
               is equivalent  to the inverse of the return period of the event, a ,
               20-year storm  is used as a basis for design.  Furthermore, it is assumed
               that a one-hour duration rainstorm is the most critical runoff event.
               Other assumptions which are used with the above analysis include:

                    -    trench sidewall percolation is one-third that of the trench
                         bottom per unit area, and
                    -    the  porosity of the rock backfill used in the trench is .33.

                                               167

-------
                                           36  40   44  48   52   56
                           PERCOLATION RATE (cm/hr.)
       Figure VIII-20.  Infiltration trench sizing diagram.
Figure VIII-20 is a graphical representation of  Equation VIII-1 for a
variety of infiltration trench widths and depths for  South Lake Tahoe.
Basically, the wider and/or deeper the trench, less trench length is
needed to infiltrate runoff from a given area.   For the Lake Tahoe
vicinity of the Sierra Nevada the following are  acceptable precipitation
values for a design 1-hour rainstorm with at least a  95 percent
reliability.
               South Lake Tahoe
               North Lake Tahoe
               Truckee
R (centimeters)

     1.78
     1.91
     1.30
                   6.   Sediment Retention Basins

The purpose of a sediment retention basin is  to trap and retain sediment
generated by construction activities.   Construction of permanent sedi-
ment retention basins  is the "last line of defense" against off-site
sediment pollution.  They should be utilized  only if drainage control
and stabilization of disturbed areas prove inadequate.

Figure VIII-21 depicts a sediment basin located in a poorly designed and
developed subdivision within Lake Tahoe Basin.  Due to the large area of
                                168

-------
Figure VIII-21.  Suspended sediment settling basin for storm runoff
   control.  Continued maintenance is required to assure adequate
                        settling capacity
disturbed slopes and the considerable runoff from impervious surfaces,
the pictured sediment basin is the most practical means of preventing
sediment pollution.

When properly designed, constructed,  and maintained sediment basins are
capable of removing a high percentage of both coarse and fine suspended
sediment from storm water runoff.   Large basins require formal design by
a professional civil engineer.

Sediment basins must be located so as to maximize effectiveness, mini-
mize cost, minimize additional disturbance and facilitate access for
maintenance.  Detailed design criteria are completely dependent upon
site specifics.  Actual design of  settling basins may vary considerably
from location to location.   When possible, however, the following cri-
teria should be considered:

          hydraulic capacity sufficient to handle a 50-year storm,
          overflow rate sufficient to settle and  retain 90 percent (by
          weight) of the anticipated  suspended sediments in the runoff
          from the tributary area  in  a  20-year, 1-hour storm,
          dam embankments completely  stabilized with side slopes no
          steeper than 2:1,
     -    easy access for maintenance and cleanout of deposited
          sediments.
                                169

-------
          7.   Drainage Control Cost-Effectiveness Analysis

 No attempt has  been made to determine the relative cost and effectiveness
'of drainage  and runoff  control techniques.  The primary reason for this
 being that the-State Board was unable to construct and specifically
 demonstrate  the majority of these methods at the project sites due to
 their relatively high cost.  Furthermore, the situations encountered at
 the project  sites were  not conducive to construction and effective appli-
 cation of the majority  of these methods.

 Mechanical Stabilization of Oversteepened Slopes

 Oversteepened,  unrevegetated slopes, with inadequate drainage contrpl,
 are perhaps  the most  significant source of eroded material in the Tahoe-
 Sierra region of California - and  the most difficult to control.  In
 most cases,  current governmental controls and grading ordinances will
 prevent the generation of highly erosive, oversteepened slopes in the
 future.  The problem therefore, is centered around the correction of
 existing problem areas  which were  created prior to the establishment of
 effective controls..  Large oversteepened areas  are widespread and
 clearly evident throughout the  Tahoe-Sierra.  Large cuts and fills can
 be found adjacent to  federal, state, county, and private highways and
 roads.  Similarly, quarries,  gravel pits, and building construction have
 left large areas of unstable eroding slopes.

 Stabilization  of bare soil areas,  as addressed  in this report, has
 emphasized revegetative techniques as  the cheapest and most effective
 method of controlling erosion.   Gently sloping  bare soil areas usually
 require only simple seeding  or planting;  oversteepened slopes require
 either reduction of slope steepness or extensive efforts to mechanically
 stabilize the  slope face until revegetative plantings are  sufficiently
 established.

 In many instances, reworking an oversteepened slope to form a less
 severely sloping area may be impractical.   Figure VITI-22  depicts  two
 slope profiles which illustrate this  point.   In Case "A" the previous
 steeply cut  slope  Cdashed line] is located in an area where the natural
 undisturbed  terrain is gently sloping.  Thus,  by constructing a small
 retaining structure at the slope toe and reworking  the face to a 1%:1
 slope, the total slope length is only slightly increased.   Case "B",
 differs only in the slope of the undisturbed natural  terrain  above the
 cut slope face.   If the same small retaining structure is  provided and
 the cut  face is reworked to a l%jl slope, the overall  slope length is
 increased by 300 percent.  The only alternatives are  to:

 1.    construct a higher retaining structure,
 2.    move the  slope toe further out into the roadway,
 3.    rework the cut face to an angle somewhat steeper than 1%:!,  or
 4,    combination of the above.
                                 170

-------
      GENTLY SLOPING
      NATURAL
      TERRAIN
    STEEP
    NATURAL
    TERRAIN
                           REWORKED
                           SLOPE FACE
                           (solid  line)
                     RETAINING
                     STRUCTURE
         CASE 'A1
CASE  'B1
 Figure yiIt-22.  Cut slope reworking.  The amount of reshaping is
  dependent upon slope of the natural terrain above the road cut.
The majority of this section is devoted to describing specific ways  in
which steep slopes may be sufficiently reworked and stabilized to allow
revegetation.  The last part of this section is devoted to a discussion
of other mechanical slope stabilization techniques which do not rely
entirely on revegetation to  provide ultimate erosion control.   By incor-
porating the following procedures, major slope reworking, leveling,
and lengthening should not be required in most instances.

            1.  Curbs and Dikes for Bench Construction

Many existing oversteepened  cut slopes, such as pictured in Figure
VIII-23 are continually undercut at the slope toe by uncontrolled drain-
age water or road maintenance crews.

In these cases, either slope toe foundations are non-existent  or they
have been placed too close to the slope to provide sufficient  protec-
tion.  The slope toe pictured in Figure VIII-23 does have an asphalt-
concrete (A-C) dike and gutter.  However, because of the excessive
steepness of the overlying unrevegetated slope and the dike's  close
proximity to the slope,  the  dike and gutter are. continually buried by
sediment eroded from the slope face.  During every runoff event the
deposited material is readily swept away, only to be replaced  once again
by further deposition of material eroded from the slope face.

At the erosion project sites, much of the recurring sediment deposition
at the slope toe was directly attributable to frost heaving and wind
                                171

-------
  Figure VHI-23.   Sloughed and eroded soil material at toe of steeply
eroding road cut at the RuBicon Properties erosion control project site.
   erosion, rather than erosion induced by running water.  This was partic-
   ularly true when the unvegetated slopes were steeper than the angle of
   internal friction Cangle of  natural repose) of the local soil.  At the
   Rubicon Properties project the  soil was decomposed granite for which the
   angle of internal friction is approximately 35 degrees (1.5:1).  The
   soil at the Northstar project site was comprised primarily of volcanic
   material also with an angle  of  internal friction of about 35 degrees.

   The easiest and least expensive manner of correcting problems created by
   unstable slope toes at the project sites was to move the slope toe fur-
   ther away from the slope face and protecting the toe from further ero-
   sion.  Gutters and dikes originally placed too close to a steep (2:1
   or greater) slope were moved away from the toe and backfilled to create
   a less steeply sloping (less than 2:1) bench.  Figure VIII-24 illustrates
   the bench which is created by moving the curb and gutter a sufficient
   distance away from the toe of the original slope.  The eroding soil
   material which would slough  over the original curb and into the gutter
   is shown as the cross-hatched area in the figured

   A reconstructed gutter will  not be effective in the long run if addi-
   tional sloughing is not controlled.  The remainder of the slope face
   must be stabilized.

   Maintenance of curbs and gutters is essential, particularly in harsh
   climates such as at Tahoe.  A total of 1,225 meters of reconstructed
   curbs and gutters were installed at the Rubicon Properties project site
                                    172

-------
       CONSTRUCTED  SLOPE
   /   TOE  BENCH
     CONSTRUCTED
     CURB 8 GUTTER
 PAVEMENT
            ORIGINAL CUT
            SLOPE FACE
                                                SLOUGHED
                                                MATERIAL FROM
                                                SLOPE FACE
                                            ORIGINAL  ROLLED
                                            CURB a  GUTTER
Figure VIII-24.  CurB,  gutter, and Bench design for staBilizing the
                toe of  a steeply eroding cut slope.
in 1976.  The equivalent  cost  Csee cost assumption at Beginning of
this section of this type of installation ranged from $12.32/meter to
$19.28/meter.  The average unit costs for installation of curBs and
gutters at the RuBicon Properties project site are as follows:

           1225 Meters of Reconstructed'Curbs'arid Gutters
LaBor Cat $16.25/hr)
Equipment (CalTrans rental rate)
Material (..23 metric  tons/meter at
          $14.30/metric ton)

TOTAL AVERAGE COST
'Equivalent Unit Cost ($/meter)

            $7.77
             4.56

             3.29
           $15.62/meter
Approximately one-third of the $15.62/meter unit cost of curB and gutter
work represents  the  cost of grading and resurfacing prior to placement
of the curB.   Two  thirds of the cost is for the actual placement of the
curB.  If a consideraBle amount of original paving or curB and gutter
structures must  Be removed, the unit cost would Be increased
suBstantially.
                               173

-------
In many cases the simple reconstruction of a curb and gutter  system fur-
ther from the slope toe may not be feasible.  The range of  alternatives
includes construction of breast walls and other retaining structures.

                        2.  Breast'Falls

Breast walls may be used to provide a slope toe "foundation"  if  it is
not feasible to reconstruct a curb and gutter system further  away from
the slope toe.  Breast walls do, however, have a considerably higher cost
than does the curb and gutter replacement mentioned above.  A definite
advantage of the large rock breast walls is that they are imposing struc-
tures and are far less likely to be damaged by road maintenance  equip-
ment than are low-lying dikes.  In all cases, plans for the construction
of a breast wall' structure must be supervised by a registered civil
engineer.  The possibility of wall failure and damage to life and prop-
erty requires that walls be carefully designed and constructed.

Rock Breast Wall

Figure VIII-25 shows the typical construction profile of a  breast wall
using large (•25 - 1.0 meter) rocks.  The following specifications are
suggested for use in the construction of this type of structure:
     ROCK PLACED
     WITH 6 = 1  BATTER
     AND THREE POINT
     BEARING.
                                                       ORIGINAL  CUT
                                                       SLOPE  FACE
 ORIGINAL ROLLED
 CURB  8 GUTTER

        PAVEMENT
                                BACKFILL AND
                                 LOUGHED MATERIAL
  Figure VIII-25.
Typical rock breast wall design for the toe of a
    steeply eroding slope.
                                 174

-------
    a.   Rock breast walls shall be 1.0 to 1.5 meters high.

    b.   Rock used shall be between .25 and 1.0 meter in diameter.

    c.   The rock breast wall shall be laid upon solid  foundation
         material or well-tamped earth if such earth would not be
         subject to erosion.

    d.   A minimum amount of excavation into the slope  shall be per-
         formed to provide a foundation for the rock breast wall.
         The breast wall may not be placed such that it reduces the
         road surface to less than the minimum required dimensions.

    e.   The rocks shall be laid with at least a three  point bearing
         on the foundation material or on previously laid rocks.

    f.   The rocks shall be placed such that their centers of gravity
         are as low as possible, with the bedding planes sloping in-
         ward toward the slope toe.

    g.   The rock breast wall shall be constructed such that the
         external wall face has a 6:1 batter.

    h.   As the rocks are placed, fill shall be laid behind and
         around the rocks and tamped thoroughly.

    i.   In addition to fill, live willow branches shall be placed in
         the interstices of the rock wall as it is constructed.  The
         basal ends of the willow branches shall extend into the back-
         fill behind the rock breast wall.

    j.   The rock breast wall shall be constructed such that a bench
         with a maximum slope of 2:1 and a minimum slope length of two
         meters can be filled behind the rock breast wall.

    k.   The top layer of rocks must be placed in a closely adjacent
         and continuous manner to minimize gaps.

     1.   In the case of rock breast wall constructed adjacent to a
         paved or impervious surface, drainage system shall be placed
         at the outside toe of the rock breast wall directing drainage
         waters to an appropriate disposal area and preventing erosion
         of the foundation material and undercutting the rock breast
         wall.

The above sample specifications are intended, only as a guide, and must
be modified to fit the particular situation.

Gab ions

In addition to the use of  large rocks for the construction  of breast
walls, gabions with cobblestone sized rocks may also be used.  Gabions

                                175

-------
are rectangular compartment containers fabricated from a triple twisted
hexagonal mesh of heavily galvanized steel wire.   Figure VIII-26 depicts
a typical one tier and two tier gabion breast wall installation.  Exca-
vation of the site for the placement of the gabions is similar to the
procedure described for rock breast walls.  For easy handling and ship-
ping, gabions are supplied folded into a flat position and bundled
together.  Each gabion is readily assembled by  unfolding and binding
together all vertical edges with lengths of connecting wire stitched
around the vertical edges.  The empty gabions are placed in position and
wired to adjoining gabions.  They are then filled with cobblestone sized
rock (10 - 30 centimeters in diameter) to one third their depth.  Two
connecting wires are then placed in each direction bracing opposing
gabion walls together.  The connecting wires prevent the gabion baskets
from "bulging" as they are filled.  This operation is  repeated until
the gabion is filled.  After filling, the top is  folded shut and wired
to the ends, sides and diaphragms.  During the  filling operation live
rooting plant species, such as willow, may be placed among the rock
material similar to the operation described for rock breast walls.  If
this is done, some soil should be placed in the gabions with the
branches and the basal ends of the plants should  extend well into the
backfill area behind the gabion breast wall.

The total labor requirement for the construction  of a  gabion structure
is estimated by one manufacturer to vary from 1,5 to 2.0 person-hours
per cubic yard (2.0 to 2.6 person-hours per cubic meter).  At the
Rubicon Properties project site gabion structures were installed using
low cost unskilled labor at a rate of 1.66 person-hours per cubic yard
(2.17 person-hours per cubic meter), including  the  loader operator's
time in filling the gabion structure with rock.

The simplest gabion structure is a .91 meter high wall using one tier
of gabions.  A second tier of gabions can be placed on top of the first
tier and set back 30 centimeters without any significant design con-
straints.  Gabion walls which are higher than two tiers (1.8 meters),
however, do require significant additional design constraints.  Such
higher "retaining wall" structures must be well designed under the
supervision of a registered civil engineer.   The  higher the retaining
wall structure, the more likely it is to fail unless it is well
designed.  As higher tiered walls are designed  and  used, the basal
foundation of the wall must be increased and/or counterforts must be
used to brace the wall against the tipping force  of the material re-
tained behind it.   In all cases, the retaining  wall must be structured
such that the "righting moment" of the wall is  at least 1.5 times the
"tipping moment" created by the retained material.

Breast Wall and Retaining Wall Costs

Breast walls were used extensively at the Rubicon Properties project
site as a means of stabilizing the toe of oversteepened, eroding slopes.
In some cases the average slope steepness was as  high as 1:1.  In the
few instances where the eroding slopes were steeper than 1:1, 2.7 meter
gabion retaining walls were used to reduce the  average slope steepness
                                176

-------
—• —— I	 -O  .
=Ju_< £ z
u_   QOJ o
^ Q- Z   —
o S ^ o: OQ

                                                    o

                                                 55
                                                 li
                                                 O Z3
                                                 X O
                                                 UJ U_
                        UJ
                        CO
z
o
CD
19
cr
CJ
E
ro




^/^
0 ^ '
m f/
s ^
2 iv
» 	 ^ 	 _u

E
o>
\
^
                                                           UJ
                                                           _i
                                                           CO
                                                                     Q
                                                                     a:
                                                                     o
                                                                     OQ
                   §
                 U- O
                 °s
                   a:
                                                                   UJ

                                 U3
                                IfN
                                                                             CO
                                       O 5s

                                       CD h-
                                       < CO
                                       O <
                                          UJ
                                          (T
                                          OQ
to
                                                                   Q
                                                                  < Z
                                                                  O =>
                                                                  X O
                                                                  UJ U.

•z.
o
m
 	 *
1
E
a>
N
\
N
CO O    §

UJ^lS
Jot00
S UJ * tO
LU o    a«i  .
co < —J o Q-
co _j =J o O

-------
above the wall to 1:1 or less.   The  following breast walls and retaining
walls have been installed at Rubicon Properties as part of the Erosion
Control Demonstration Project:
     1.3 meter high rock breast wall
     0.9 meter high gabion breast wall  (1 tier)
     1.8 meter high gabion breast wall  (2 tier)
     2.7 meter high gabion retaining wall C3 tier)
                                                 TOTAL
                                                 Length

                                                  350 m.
                                                 1500 m.
                                                  450 m.
                                                  200 m.

                                                 2500 m.
In addition to the above walls,  two  sections, totalling 50 meters in
length, of a 0.6 meter high rock wall were constructed at the Northstar
project site using manual labor  only.  The rocks used for the Northstar
walls were up to 40 cm in diameter and weighed up to 50 kilograms, other-
wise known as "two-man rocks".

Table VIII-2 presents the equivalent unit materials, equipment and labor
costs for the construction of a  variety of breast wall structures.  The
commercial delivered price of all  rock at the project site is assumed to
be $8.40 per ton.  A 0.9 meter high  wire mesh gabion basket costs approx-
imately $9.80 per meter of length.   Little equipment was required for
construction of the 0.6 meter "two-man" rock breast wall due to the
entire rock placement operation  being conducted by manual labor.  For
the larger rock breast walls, a  heavy duty loader with a cost of $27.00
per hour is required continuously.   In the case of the gabion structures,
however, the heavy duty loader is  required for a small percentage of
total construction time, for the gabion filling operation only.  If
organized efficiently, the filling operation can proceed quite rapidly
compared to the rest of the gabion construction procedure.  As stated
at the beginning of this section,  the total cost of labor is assumed
to be $16.25 per person-hour.

The total cost of any particular wall type is greatly influenced by the
highly variable unit cost of materials and labor.  For example, if large
boulders suitable for rock breast  wall construction are present at a
prospective erosion control site,  the total cost of 1.0 meter rock breast
wall could be reduced to $50.00  per  meter.  Similarly, if an unskilled,
low cost labor force (e.g. $5.00 per person-hour total unit labor cost)
could be used to set up and wire gabions together, the total cost of a
0.9 meter gabion breast wall could be reduced from $58.61 per meter to
less than $45.00 per meter.  Less  expensive sources of rock could fur-
ther reduce the gabion structure's unit cost.

Concrete gravity walls, or counterforted reinforced concrete walls, were
not used at either the Rubicon Properties or Northstar project site for
two primary  reasons:
     a.
     b.
their relatively unnatural appearance, and
their extremely high  costs.
                                178

-------
TABLE VIII- 2
COMPARATIVE BREAST WALL CONSTRUCTION
EQUIVALENT COSTS*
UNIT COST ($/METER)
WALL TYPE
0.6 meter "two-man"
breast wall
1.0 meter rock
breast wall
1.35 meter rock
breast wall
0.9 meter gabion
breast wall
1.8 meter gabion
breast wall
2.7 meter gabion
retaining wall
MATERIALS
rock 4.00
11.04
13.80
22.40
44. .80
72.80
* Based upon documented construction at
assumptions at front of this section.
EQUIPMENT
2.91
22.62
28.28
5.71
11.42
18.56
project sites
LABOR
22.94
27.50
34.38
30.50
61.00
99.13
and stated
TOTAL
29.85
61: 16
76; 45
58.61
117.22
190.48

A 1.0 meter concrete gravity wall, for example is estimated to cost
approximately $150.00 per linear meter.  The higher expense is due pri-
marily to the cost of materials and labor required for the construction
of the wooden forms necessary  for the in-place fabrication of the concrete
walls.  Preformed concrete walls may be somewhat cheaper, but still not
competitive with rock or gabion walls.

Other materials, such as redwood planks or railroad ties, may be used in
the construction of breast walls or retaining structures.  Use of these
materials has not been evaluated at the project site.  In the case of
the railroad ties, a firm supply of these items was not found.  In the
case of redwood, the project staff did not believe the construction of
retaining structures was an appropriate use of this limited resource.

Furthermore, the cost of the skilled carpentry labor required for the
construction of these walls would have prohibited their construction
using limited project funds.   The cost of constructing a 0.9 meter red-
wood retaining wall is estimated to be approximately $45.00 per meter.
Two-thirds of this cost ($30.00) would be for materials.
                                179

-------
Breast Wall Effectiveness

Determining which type of slope toe stabilization method to employ is
almost entirely dependent upon the cost of  the particular structure.
Any sound structure which provides dependable protection for the slope
toe is sufficient.  Porous walls,  such as wooden walls, gabions, or
ungrouted rock structures, are preferable.   Such structures, if properly
designed and constructed, will allow for the easy passage of surface
water yet retain the eroding soil  material.  In a few cases at the
Rubicon Properties project site, the interstitial spaces in the rock-
wall structures were too large. These spaces allow for the passage of
seepage water, but they also allowed soil to erode through the wall.
Problems such as these can be prevented by  careful construction practices,

Frequently, gabions are criticized as being unattractive "bird cages".
It is argued that such "unsightly" structures should not be used for
erosion control in highly visible  areas, such as adjacent to roadways.
Indeed, if large rocks are readily accessible, inexpensive, and near to
a proposed erosion control site, they should be used in the construction
of large rock walls.  If rock must be imported, it is likely that the
cost of breast wall construction would be somewhat lower if gabions are
used.  Because of the high porosity of a filled gabion, soil can be
placed in the gabion or will gradually filter into the voids.  This will
allow vegetation to establish itself on and around the gabion structure.
The gabion structures used at the  project site have not been in place a
sufficient length of time to evaluate the success of establishing vege-
tation.  Those areas where willows have been placed in and around the
gabion structure, however, are expected to  rapidly produce good vegeta-
tive growth and cover.

               3.  Slope'Scaling arid Overhang Removal

Proper slope scaling is a frequently neglected integral step in the
stabilization of eroding cut and fill slopes.  This is particularly true
if the erosion control measures are installed some time after the orig-
inal slope disturbance took place.  If gullies, rocky areas, or other
unstable sites are allowed to remain without proper treatment, the estab-
lishment of vegetative cover on an eroding  slope will be considerably
more difficult.  It is far more cost-effective to adequately prepare an
eroding slope prior to revegetation, than to come back time and time
again to replant these disturbed areas.  Figure VIII-27 shows a work
force scaling an eroding cut slope.

Rocks pictured in Figure VIII—27 were subsequently used elsewhere to
rock-line and stabilize an eroding drainage  swale.

Slope scaling should be conducted  after breast walls or other bench
structures are formed at the toe of the slope.  Exceptionssare very
large rocks or stumps which may require prior removal to avoid damaging
the slope toe structure.  The following is an example set of specifica-
tions which may be used to describe the scaling process:
                                180

-------
          Figure VIII-27.  Scaling an eroding cut slope.
Scaling Process Specifications

     a.   All loose materials, exposed rock, and uneven surfaces shall
          be scaled and  removed to the toe of the slope.

     b.   Precautions  shall be taken to insure the safety of workers on
          steep slopes C2:l or greater) by means of safety ropes and
          harnesses anchored securely to the top of the slope.

     c.   While removing large rocks from the slope, adequate precau-
          tions shall  be taken to control their movement.

     d.   If the scaling is being conducted on a cut slope adjacent to
          or above a travelled roadway, the passage of traffic on the
          roadway adjacent to the section being scaled shall be restric-
          ted during periods when scaling is being conducted.

     e.   All scaled materials shall be immediately removed from the
          road surface and stockpiled at a site approved by the project
          engineer. In  no case shall scaled material be placed within a
          gutter or drainage swale, nor shall it be placed on a road
          surface for  longer than an 8-hour period.

     f.   Scaled material shall be stockpiled in locations not subject
          to concentrated runoff.  Siltation berms and impervious cover-
         " ings must be used to prevent erosion from the stockpiled area.
                                181

-------
Overhangs, as defined in this  report, are the excessively steep portions
of eroding slopes,  with slopes greater than 1:1, such as are frequently
found at the crown of eroding  cuts.  When cut slopes are initially exca-
vated, overhangs are usually non-existent.  However, if the majority of
a steeply cut slope remains  unstabilized after initial excavations,  the
mid portion of a slope will  generally erode more rapidly than the remain-
der of the slope.  The erosion will continue until a slope angle equal
to or less than the angle of internal friction of the soil has been
achieved.  The crown of the  slope usually erodes more slowly than the
mid-portion due to vegetation  in undisturbed, natural terrain above the
lip of the slope.  Although  the  overhangs are more stable than the
remainder of the slope, they will continue to erode, albeit more slowly.
If plantings are placed on the lower portions of the slope without over-
hang removal, they may become  buried or otherwise disturbed by material
sloughed from the overhang.  Furthermore, overhangs are frequently
near vertical.  Unless such  areas are rounded and reduced in steepness,
it.is difficult, if not impossible, to establish plantings.

Overhang removal should also be  conducted after construction of breast
walls or other slope toe stabilization structures.  Again the only
exception is in the case of  large stumps or boulders.  Figure VIII-27
depicts a manual overhang removal operation.  Over 95 percent of all
overhangs at the Rubicon Properties and Northstar project sites were
removed in this manner.  Following is an example set of specifications
which may be used.

Overhang Removal Specifications
     a.
     b.
     c.
          Any overhang areas steeper than 1:1 (horizontal to vertical)
          at the slope crown shall be regraded and rounded to a maximum
          slope of  1.5:1.

          All trees to be removed from the overhang area shall be
          clearly marked by the project engineer.

          Soil removed from the overhang shall be placed behind the
          slope toe stabilization method (i.e., curb, breast wall,
          retaining structure) employed at the toe of the slope.

Scaling and Overhang Removal Cos ts

At the Rubicon Properties project site, approximately 300 cubic meters
of overhang material were removed and placed as fill behind breast  walls
and A-C dikes at the toe of eroding slopes.  With the exceptions  of the
use of the loader for pulling  trees and stumps and a backhoe for  remov-
ing 51 cubic meters of overhang, all scaling and overhang removal were
performed by manual labor.  Manual removal of overhangs required  about
2.5 hours per cubic meter of overhang.  A current construction cost
estimating handbook (51) indicates that loosening of earth by hand  with
a pick requires 2.0 - 4.0 hours per cubic yards (2.6 - 5.2 hrs. per
cubic meter).
                                '3.82

-------
                               TABLE VIII-3

                  COMPARATIVE OVERHANG REMOVAL AND S GALING
                             EQUIVALENT COSTS

                                            UNIT COST C$/CTJBIC METER)
ACTIVITY
                             MATERIALS
Manual scaling and
overhang removal with
aid of loader in
removing stumps
EQUIPMENT

   1.91
Overhang removal
with backhoe

Overhang removal
with crane*
                                               2.13


                                               6.47


*    Estimated rate of removal same as for Backhoe.
                4.87


                5.47
 7.00


11.94
     Table VIII-3 illustrates  the costs of overhang removal and scaling as
     experienced at the Rubicon Properties project site.  Manual scaling and
     overhang removal is considerably more expensive than more mechanized
     methods employing heavy equipment such as backhoes and cranes.   However,
     in many instances cut slopes are so long that it is difficult to find
     equipment with sufficient reach to allow removal of the overhang at the
     slope crown.  Furthermore, the labor force used at the Rubicon Properties
     project site was so inexpensive that the unit cost of manual scaling and
     overhang removal was essentially equivalent to the unit cost of renting
     mechanized equipment to perform these tasks.

     An additional cost of scaling and overhang removal is the cleanup of
     debris which may be deposited at the toe of the slope.  At the Rubicon
     Properties project site,  the average unit cost for debris cleanup on
     roadways adjacent to cut  slopes was $4,086.00 per hectare of cut slope
     surface.  Approximately 60 percent of this cost is for labor and 40
     percent is for equipment  needed to transport waste debris to an appro-
     priate disposal site.

                           4. Contour Wattling

     "Contour Wattling" was described by Kraebel £52) as early as 1936 in a
     USDA circular, but has seen little practical use in the United States
     outside of limited experimental applications.  Kraebel defined "contour
     wattling" as "the packing of lengths of brush into continuous thick
     'cables' partially buried across a slope at regular contour intervals
     and supported on the lower side by stakes".  Experimental work on con-
     tour wattling prior to this report has been conducted by the Department
                                    183

-------
of Environmental Horticulture,  University of California, Davis, and the
California Department of Transportation (CalTrans) as a means of control-
ling erosion on steep embankments adjacent to state highways in the Lake
Tahoe Region of the Sierra Nevada.  Contour wattling is particularly
effective on slopes which approach,  or are steeper than, the friction
angles (angle of repose) of the local soil.   Advantages of contour wat-
tling are as follows:

1.   The placement of wattling  bundles into  the  eroding slope provides
     local stabilization to the upper .2 to  .3 meter of soil surface.
     This prevents down slope movement of surface soil.

2.   Contour wattling rows placed at repeated intervals effectively
     break a relatively long slope into a series of benched and shorter
     slopes.  During heavy rains these repeated  barriers prevent the
     formation of large gullies.  Wattling rows  act as effective minia-
     ture "percolation trenches" during a heavy  runoff condition.  This
     is particularly true if the contour wattling rows are left slightly
     exposed.

3.   By keeping the soil in place, contour wattling allows the establish-
     ment of vegetation on a denuded slope.   A slight bench is formed at
     each wattling row allowing for  the germination and growth of seed
     material placed there either artificially or by natural processes.
     If the wattling bundles are made up of  sprouting species, the root-
     ing of the wattling itself will provide effective stabilization of
     the slope surface.

4.   One of the best means of mechanically stabilizing steep slopes
     outside of ext nsive (and  expensive)  engineered retaining structures.

Contour Wattling Procedure

The following general procedure, adapted from Leiser (46), should be
specified in the installation of contour wattling (see Figure VIII-28):

     a.   Wattling bundles shall be  prepared from live shrubby material,
          preferably of species which will root, such as willows.

     b.   Wattling bundles may  vary  in length, depending upon material
          available.  Bundles shall  taper at the ends.  Butts of stems
          shall be from 2 to 4  centimeters in diameter.

     c.   Stems shall be placed alternately  in each bundle so that
          approximately one-half of  the butt ends are at each end of the
          bundle.

     d.   When compressed firmly and tied, each  bundle shall be 20 cen-
          timeters in diameter  plus  or minus 5 centimeters.
                                184

-------
185

-------
     m.
     n.
Bundles shall be tied on not more than 40 centimeter centers
with two wraps of hinder twine or heavier tying material with
a non-slipping knot.

Bundles shall be prepared not more than one day in advance of
placement except that if kept covered and wet they may be
prepared up to seven days in advance of placement.

Grade for the wattling trenches shall be staked with a hand-
held level, or similar device, and shall follow the horizontal
slope contours.

Trenches shall be one meter vertical spacing or other as speci-
fied by the project engineer.

Bundles shall be laid in trenches dug to approximately one-half
the diameter of the bundles with ends of bundles overlapping
at least 30 centimeters. The bundles shall be as long as
necessary to permit staking as specified below.

Bundles shall be staked firmly in place with vertical stakes
on the downhill side of the wattling, not more than 0.5 meters
on center and vertical stakes through the bundles on not more
than 1.0 meter centers. Where bundle overlap occurs, an addi-
tional stake shall be used  at the mid-point of the overlap.
Bundle overlaps shall be tied with a vertical stake through
the ends of both bundles.

Stakes shall be construction stakes C5 cm x 10 cm x 61 cm  or 5
cm x 10 cm x 91.4 cm diagonal cut).

All stakes shall be driven  to a firm hold and a minimum of 45
centimeters deep.  Where soils are soft and 61 centimeter
stakes are not solid (i.e., if they can be moved by hand)  91.4
centimeter stakes shall be  used.

Work shall progress from the bottom of the cut or fill toward
the top, and each row shall be covered with soil and packed
firmly behind and on the uphill side of the wattling by tamp-
ing or by walking on the wattling as the work progresses,  or
by a combination of these methods.

The downhill "lip" of the wattling bundle may be left exposed
          when staking and covering are completed.
          must be rigorously adhered to.
                                         However, step
"m"
Willows were the only plants used for contour wattling as part of  this
erosion control project,  although other quick rooting and sprouting
species may also be used.

The timing of willow cutting and cutting site selection can make a great
difference in productivity of any willow wattling operation.  When a
                              186

-------
Variety of sites are available,  the following criteria should be con-
sidered before making a final  selection.  First, try to schedule willow
wattling for late fall or early  spring, when willows are dormant or
nearly dormant.  Results at Rubicon Properties show markedly increased
growth and survival of wattling  cut and placed in May and September,
over wattling cut and placed in  June and July.  Special handling, such
as covering wattling with wet  tarps during transport and frequent irri-
gation after placement may improve results of summer wattling.  However,
results at'Rubicon Properties, even with this special handling were poor
in comparison to early spring  and late fall wattling. • Second, the
growth habit of the willow plant is important.  Shoots, 2-3 meters
long with few cross branches and few dead branches, are the most desir-
able.  These branches form more  uniform and easily tied bundles, and the
plants' growth habitat is more open and easier to work in.  Third, the
willow cutting site must contain enough satisfactory wattling material
to justify the time required to  conduct the cutting operation.  Gener-
ally speaking, if 'approximately  400 square meters of willow plants are
available in a single area, the  area is cost-effective to exploit.
Fourth, the actual travel time to the cutting site is important.  Cut-
ting sites used as part of this  erosion control project have ranged from
4 kilometers to as far away as 40 kilometers from the installation site.
Substantially greater transportation distances would increase wattling
costs considerably.

An adequately equipped and experienced five-person work crew should be
able to cut, collect, and bundle one hundred 2.5 meter wattling bundles
from one site in one 8-hour period.  A production rate of two to three
wattling bundles per person-hour may be reasonably expected.  The only
equipment required for the task  of willow cutting and wattling bundling
are:  pruning shears, binder's twine, a sharp knife, a long bed half-ton
pick up truck, a large tarp, and the necessary safety equipment, such as
hard hats and gloves.  A chain saw can be used to speed up the willow
cutting operation, but is extremely hazardous and requires experienced
personnel and additional safety  equipment.  An electric strapping tool
requiring a portable generator was experimented with, but was found to
be no more efficient than manually tied twine for tying the wattling
bundles together.  Furthermore,  aesthetic and environmental objections
might be raised over the use of  nondegrading plastic strapping material.

Several tasks relating to wattling installation should be completed
prior to the arrival of the wattling bundles at the project site.  First,
the alignment of the contour wattling rows must be determined.  An ini-
tial stake is driven at the bottom of a slope face.  From this point,
stakes are placed at desired intervals up the slope face.  Once this
initial staking is completed,  contour stakes are driven at approximate
6-meter intervals across the slope face along each contour, utilizing a
hand held optical level.  Finally, stakes are "eye-balled" in at 0.5
meter intervals along the contour.

The actual willow wattling installation must function as a dynamic pro-
cess.  Trenching, placing, staking,  and burying of the willows must take
place in rapid succession in order  to minimize soil and plant moisture
                                187

-------
loss and maximize plant survival.   Crew members  should start trenching
and preparing the ground,  while others  finish bundling the wattling and
start placing them in the lowest trench.   Once the lowest wattle is
installed, the digging of the next higher trench may be started.  This
staggered trenching is important so that  as  the  higher trenches are dug,
sloughed,soil falls into the lower trenches.  If this process is oper-
ating properly, all material sloughed from above should land on installed
wattling bundles.

Willows are installed so that approximately  one-third of the bundle
extends above the slope grade, enabling it to intercept overland runoff.
For most willow bundles, 3-4 stakes driven through the bundle are
sufficient to hold it in place.  An additional stake is driven through
the overlapping ends of adjacent bundles.  A total of 3.5 construction
stakes are required for every meter of  contour wattling.  The end wat-
tling bundle should be angled up the slope to prevent any collected
runoff from flowing around the end.  The  soil is then replaced and packed
around the base of the wattling bundles.   Again, this must be completed
shortly after the willows are installed.   The presence of adequate soil
moisture adjacent to the bundles is imperative for plant survival.  In
an effort to provide ample soil moisture  for willow growth and rooting
at the Rubicon Properties and Northstar projects sites, all wattling
installed at these sites was heavily soaked  with irrigation water immedi-
ately after installation.   In the case  of mid-summer wattling plantings
(July - August 1976) at Rubicon Properties,  the  willow wattled slopes
   Figure VIII-22.  Contour willow wattling  installation at the
              Northstar erosion control project site.

                                188

-------
were repeatedly soaked at no greater than one-week intervals throughout
the summer.  The rate of willow installation  is  limited primarily by the
rate at which the trenches are prepared.   When the contour wattling
operation is functioning properly,  approximately one hundred 2.5 meter
wattling bundles may be stalled by  a five-person crew in one day.
Figure VIII-29 depicts a typical wattling installation in progress.

Contour Wattling Cost

By making the necessary arrangements and obtaining a permit from the
U. S. Forest Service, willows may be harvested on Forest Service lands
for the purpose of erosion control.  It is therefore assumed that plant
materials cost for willow wattling  is negligible.  The only substantial
materials cost is for the construction stakes used to hold the wattling
bundles in place.  When purchased in large quantities, the unit cost is
about $.25 per stake.  Approximately 2,500 meters and 1,500 meters of
willow wattling bundles were installed at the Rubicon Properties and
Northstar project sites, respectively.  At Rubicon Properties 238 person-
hours were spent in the harvesting, and transporting 2,000 meters of
willow materials 30 miles to the project site during the summer and fall
.of 1976.  In addition, a total of 377 person-hours were spent in the
bundling, staking, and burying of these bundles. The average spacing
between wattling rows was 1.85 meters.

Equipment required for the willow wattling operation consists of a half-
ton pick up truck, a chain saw, and assorted  hand tools and safety equip-
ment.  Costs for the equipment is assumed to  be  $4.00 per hour for a
five—person work crew.  The willow  wattling cost data is summarized as
follows:
                                             $/meter
               Materials
               Equipment
               Labor
                              TOTAL
$0.88
 0.25
 5.01

$6.14/meter
The total cost of $6.14 per meter for willow wattling is roughly equiva-
lent to costs cited by Leiser (.46) of $6.56 per meter.  The cost summary
shown above is based upon the cost assumptions  used in  this report as
listed at the beginning of this appendix.   Labor  is assumed to cost
$16.25 per hour.

Fully 82 percent of the cost of willow wattling is  for  labor.  If less
expensive labor is available contour wattling costs may be drastically
reduced.  At the Northstar and Rubicon Properties project sites,
unskilled college students, Youth Conservation  Corps workers  (YCC) and
California Conservation Corps workers (CCC), were used  to install con-
tour wattling.  Based on an estimated cost of $5.00 per person-hour for
wages, supervision, transportation, and minimum benefits, contour wat-
tling installed by these groups cost approximately  $2.67 per meter
installed.
                               189

-------
                         5.   Other Methods

The methods for the mechanical stabilization of oversteepened slopes
discussed previously in this section require revegetation of the slope
to achieve the highest order of effective erosion control.  There are,
however, several other methods of mechanically stabilizing oversteepened
slopes which do not require, nor depend upon, revegetation to effectively
control erosion.  The wide variety of products and techniques available
to achieve non-vegetative oriented control  are too numerous to mention
in any detail.  A few representative techniques will be briefly touched
upon in this section.  None  of these approaches were demonstrated at
either the Northstar or Rubicon Properties  erosion control project sites;
they were excluded by the following selection criteria:

     -    the judgement that they were aesthetically unpleasing in com-
          parison to vegetation, and
     —    the cost of materials and installation which absolutely pro-
          hibited their use  as part of this project.

Examples of this "non-revegetative" approach to mechanical stabilization
of oversteepened slopes include gabion revetments, concrete anti-erosion
grid revetments and gunite revetments.  A revetment, as used in this
text, means an artificial structure devised to cause earth to stand at a
steeper slope than it would  naturally assume.

Gabion Revetments

Wire mesh gabions may be used to form breast walls and retaining struc-
tures at the toe of a steeply eroding slope as discussed in a previous
section.  These devices may  also be used to completely cover an eroding
slope in the form of a revetment.  In order to place rocks in gabion
revetments, extensive heavy  equipment such  as a loader and/or crane with
a bucket attachment is required.  Wire mesh gabion baskets may be obtained
in a variety of thicknesses  to form a revetment structure.

Gabion revetment structures  do have the advantage of being relatively
easily revegetated.  Soil placed in the interstices of the rock fill can
support vegetation.  Once the movement of soil from the slope is stabi-
lized by the use of a gabion revetment, the natural invasion of native
plants may be expected to occur much more readily.  The porous nature of
the gabion revetment also allows easy passage of seepage water that may
occur naturally on the slope.  Because of their great flexibility, gabion
revetments cannot crack or otherwise lose their structural integrity
even if considerable shifting or settling occurs.

Concrete Anti-Erosion Grid Revetments

A variety of these concrete  anti-erosion grids are currently available.
One type of concrete grid is precast, slotted, .25 square meter blocks.
The manufacturer indicates that these blocks may be placed on slopes up
to a 1:1 angle.  Similar to  a gabion revetment, the perforations in the
grids would facilitate the establishment of vegetation.  One apparent
                                190

-------
                               TABLE VIII-4'

                       ESTIMATED REVETMENT COST FOR
                    STABILIZATION OF'OVERSTEEPENED SLOPES
REVETMENT
Gabion Revetments

Concrete Anti-
erosion Grids

Gunite Revetments
MATERIALS

 $12.50

  12.84


   5.05
UNIT COST ($/SQUARE METER)

EQUIPMENT      LABOR      TOTAL

  $4.16       $11.12     $27.78

               11.83      24.67
   2.86
2.86
10.76
     disadvantage is the absolute inflexibility of the individual blocks.   A
     slope where the grids are used must be completely level prior to instal-
     lation, an added disadvantage of  the grids is their high unit weight.
     One type of grid weighs 42 kilograms per block.  Unlike gabions, which
     may be filled by means of heavy equipment, anti-erosion grids must be
     placed individually with manual labor.  Other applications of this par-
     ticular type of product are many  and varied.  One application which
     should receive further evaluation in the Tahoe-Sierra region of California
     is their use as pervious paving surfaces for parking lots.  Because of
     their slotted perforations, concrete anti-erosion grids should be able
     to reduce or eliminate storm water runoff from otherwise impervious
     surfaces and thereby lessen the need for extensive storm water infiltra-
     tion works.

     Gunite Revetments

     Gunite is sprayed concrete applied directly to a subject by means of an
     air jet.  A mechanical feeder, mixer,  and compressor comprise the prin-
     cipal equipment for this method of placement.  Gunite can be effectively
     pplied to near vertical slopes and is  usually applied to a depth of
     about 10 centimeters.  Disadvantages include gunite's rigid and non-
     porous structure.  Gunite may be  subject to cracking or chipping if any
     settlement or shifting occurs. Because of gunite's non-porous nature,
     extensive seepage lines or "weep-holes" must be placed on gunited slopes
     to prevent the buildup of hydrostatic  pressure which could lead to the
     failure of the gunite revetment.   Use  of gunite will increase the amount
     of storm runoff from a particular area.  If its use leads to extensive
     runoff and off-site erosion problems,  use of gunite should be discouraged.
     Furthermore, objections may be made regarding the use of gunite due to
     its unnatural appearance.

     Due to the above problems encountered with  the use of gunite, its use
     should be limited to only special problem areas.  One type of problem
     for which gunite may be useful is the control of erosion from steep,
                                     191

-------
     near vertical decomposing granite construction  cuts.  Vegetation is next
     to impossible to establish in such locations and  the existing decomposing
     granitic rock is already highly impervious.

     Revetment Costs

     The slope treatments mentioned above are  considerably more expensive
     than revegetative erosion control measures.  For  this reason alone, use
     of revetment structures should be limited to special situations and
     extreme problem areas where other methods are unlikely to succeed.

     Table VIII-4 summarizes the estimated costs of  the above discussed revet-
     ment structures.  Cost data is derived solely from manufacturers' and/or
     contractors' estimates.  The actual unit  costs may vary depending on
     transportation, site accessibility,  labor costs,  and area covered.  The
     values given in Table VIII-4 are rough estimates  for comparative purposes
     only.

F.   Permanent Vegetative Erosion Control

     Erosion control methods described in this section are treated by this
     report as the best approach to the permanent control of erosion from
     disturbed areas.  Effective revegetation  will increase the abstraction
     and permeability of the disturbed area and reduce the impact which storm
     water runoff may have on down gradient areas.  Furthermore, once estab-
     lished, vegetation requires a minimum amount of maintenance, particularly
     if native plants are able to "reinvade" a previously disturbed area.
     Achieving satisfactory establishment of vegetation is dependent on cli-
     matic conditions.  Unless irrigation is provided, revegetation should
     only be conducted in the Tahoe-Sierra region in the fall or preferably
     the early spring.

     The possible need for "follow-up" plantings and seedings must be acknowl-
     edged.  In most situations,  follow up seedings are relatively inexpensive
     (less expensive than providing irrigation) and can easily be provided
     for.  If a fall seeding does not establish satisfactory growth due to
     frost heaving or other causes,  additional seedings should be conducted
     in the following spring.   In all cases, vegetative erosion control in
     the Tahoe-Sierra, albeit relatively inexpensive,  is a somewhat specula-
     tive venture.            '

     On gentle slopes (2:1 or less),  the vegetative techniques described
     herein, singly or in various combinations, should be effective in con-
     trolling erosion from these disturbed areas.  However, on steeper dis-
     turbed terrain, or in situations where drainage control is poor, slope
     stabilization and proper drainage control prior to revegetation is
     essential to successful establishment of  plants.  At the Northstar and
     Rubicon Properties erosion control sites,  the use of contour willow
     wattling, for example,  has more than doubled the survival of other plants.

     A wide variety of revegetative techniques are discussed in this section,
     ranging in expense from less than $.10 per square meter for seeding and
                                    192

-------
mulching to over $2.00 per square meter for native plantings or manual
installation of various mulch nettings and blankets.  However, in many
instances, a considerable commitment of funds is required for mechanical
slope stabilization prior to revegetation.  The unit erosion control
cost for slopes that require massive slope stabilization in the form of
retaining walls frequently exceed $20.00 per square meter of slope face.
As eroding slopes become steeper and longer9 the vegetative portion of
effective erosion control represents only a small portion of the total
cost.

This section on vegetative erosion  control will deal with the following
subject areas:

     -    willow staking
          container and bare root plants
     -    seed and fertilizer
     -    seeding and mulching  techniques
     -    fiberglass roving

All of the above planting techniques, with  the exception of fiberglass
roving, were used extensively at either the No.rthstar or Rubicon Proper-
ties erosion control project sites. The discussion of seeding and mulch-
ing 'techniques is particularly  extensive and includes hydromulching,
straw mulching, straw tackifying, and mulch nets and blankets.

                       1.  Cut  Willow'Stakes

Planting a slope with cut willow stake cuttings can be an effective
method of providing a quick, cheap  method of revegetating eroding slopes.
Other plants such as dogwood ('Cbrrius) and alder (Alnus) may also be
satisfactory for this purpose but were not  tried on these projects.
Willow staking has been conducted with considerable success even on
relatively dry, south facing, exposed slopes.  The best results with
willow staking are achieved if  the  following procedure is rigorously
adhered to.

Willow Staking Procedure

Plant materials are gathered in much the same manner as for the contour
wattling operation.  Sources of willow are  readily available in the Lake
Tahoe Basin by gaining a use permit for removal from Forest Service
lands.  Willow shoots may be cut by either  pruning shears or a chain
saw.  Small branches should be trimmed from the willow shoots ranging
from 1 to 2.5 centimeters in diameter.  The shoots are cut into 15 to 45
centimeter lengths using either a hand axe  or a circular saw and marked
with spray paint at their basal ends.  The  cut length of the willow
stakes is dependent upon the ease with which they may be driven into the
ground.  The stakes should be as long as possible, up to 45 centimeters,
with no more than 2-4 centimeters exposed above the slope surface once
they are driven in place.  The longer the stake, the better chance it
has  for survival.
                                193

-------
     Figure VHI-30.  New growth on a successfully planted willow stake.
Materials

Equipment

Labor*

 -  harvesting

 -  cutting

 -  installation

TOTAL
                                TABLE VIII-5
                       WILLOW S TAKING EQUIVALENT'COST
                               TIME
                        EQUIVALENT COST
                            $/stake
    hr/stake

CNo materials  other  than willows are required.)

      .007                           .028
.008

.010

.009

.027
                                     .130

                                     .163

                                     .141

                                     .462
*Note:  Equivalent labor cost is  assumed to be $16.25 per person-hour.
                                    194

-------
On unconsolidated decomposed granitic soils, willow stakes may be placed
with relative ease at any time.   On harder  soils with higher clay con-
tent, use of a star drill or other devices  may be required to make plant-
ing holes.  Due to the very dry  summertime  conditions in the Sierra
Nevada, willow staking should be conducted  in either the early spring or
late fall' to be assured of adequate soil moisture to support growth.  In
most instances the rate of successful plant growth from willow staking
appears to be much greater than  from willow wattling.  As is true with
contour wattling, willow stakes  should be cut immediately prior to
installation, and never stored for longer than a 12-hour period unless
they are kept cool and moist. Willow branches for stakes may be stored
up to 7 days if properly stored.  A successfully planted willow stake is
pictured in Figure VIII-30.

Willow Staking Cost

Equipment required for the willow staking process includes a half-ton
pick-up truck, chain saw, and assorted hand tools.  The cost of this
equipment is assumed to be $4.00 per hour for a five-person work crew.
The willow staking cost data, as performed  at Northstar, is presented in
Table VIII-5.  Willow stakes were placed at a density of about four per
square meter..

                             2.   Plants

Reestablishment of native plants is generally held to be ideal revegeta-
tive approach for erosion control.  Reasons for this include:

1.   aesthetically pleasing control method, blending in with the sur-
     rounding natural environment

2.   lower fertilizer requirements for native species

3.   lower water requirements for native, drought tolerant species

Difficulties which are encountered with revegetation using native species
include:

1.   plants are not generally available except by advance contracts with
     growers

2.   plants are relatively expensive due to difficulties of propagation
     and cultivation resulting in greater risks  to growers

3.   poor survival of small seedlings and cuttings when given a minimum
     amount of attention and care

4.   frequently provide less than adequate  ground cover for effective
     soil stabilization and erosion control

Considerable work has been recently conducted by the Department of
Environmental Horticulture, University of  California,  Davis, in
                                195

-------
propagation of native Sierran plants for erosion control and revegeta-
tion.  Propagation methods for such plants are covered in detail in
Appendix A.

Plants received at the erosion control project sites came in a variety
of containers:

1.   Shrubs — rooted cuttings and seedlings,

     -    7.5 cm. peat pots
     -    15 cm. and 25 cm. PVC deep conical tubes
     -    13 cm. and 25 cm. thin ployethylene book planters

2.   Bare root tree seedlings,

     -    bundles of 50

3.   Grass seedlings,

     -    7.5 cm. peat pots

The principal plants used as part of this erosion control demonstration
project are as follows (.for a complete listing, refer to Appendix A):

1.   Shrubs

     a.   ArGtostaphylos patula (.greenleaf manzanita)
     b.   Arctostaphylos nevadensis (pinemat manzanita)
     c.   Artemesia. trideritata (big sage)
     d.   Ceanothus prostratus (squaw carpet)
     e.   Purshia tridentata (bitterbrush)
     f.   Penstemon newberryi (mountain pride)
     g.   Various Lupinus species (lupines)
     h.   Various Salix species (willow)
     i.   Prunus emarginata (bitter cherry)
     3'   Atriplex canescens (salt bush)
     k.   Chrysothamnus hauseosus (rabbitbrush)

2.   Bare root tree seedlings
     a.
     b.
     c.
     d.

     Grass
Pinus jeffreyi (Jeffrey pine)
Pinus lambeftiana (sugar pine)
Abies magnifica (red fir)
Abies concolor (white fir)
     a.   Various rhizominous wheatgrasses.

Judging from early results, the best success has  been achieved by Purshia
tridentata, Artemesia tridentata, Penstemon  newberryi, Atriplex  canescens,
Pinus jeffreyi, Chrysothamnus nausebsus,  and the  grass clones.
                               196

-------
Planting Procedure

Once plants have been transported to the erosion control site, they
should be acclimated for approximately 1-2 weeks.  During this period,
plants should be watered only when necessary, with a final watering just
before planting.  Bare root seedlings should be delivered to the erosion
project site in the early spring and planted as soon as possible.  Those
seedlings not used immediately should remain boxed in a cool, dark place
and thoroughly doused with water daily.

At the project site, the actual planting operation requires three or
more people.  Two or more individuals are involved with placing the
plants in the ground, while at least one individual is responsible for
supplying each "planter" with plants as needed.  On less severely slop-
ing sites, each "planter" may be responsible for providing his/her own
supply of plants.  Planting should proceed from the top of the slope to
the bottom at staggered intervals along the contours of the slope face.
This prevents soil disturbed by foot traffic from being sloughed and
deposited on plants lower on the slope.  Each "planter" is responsible
for the following planting procedure (see Figure VIII-31):

1.   On a loose sloughing slope (such as decomposed granite), dig a hole
     just large enough for the root ball of the plant.

     On consolidated slopes, the above procedure may be followed, or dig
     a shallow bowl shaped excavation and form a slight brim on the
     downhill side.  An additional excavation large enough to contain
     the root Ball of the plant is made in the low point of the bowl,
     normal to the surface.  The purpose of the bowl is to allow surface
     irrigation and to trap rainwater.  Care must be taken to remove all
     loose soil around the bowl which may erode into the bowl and bury
     the plant.

     An additional excavation made to the dimension of the plant container
     is made in the low point of the bowl normal to the surface.

2.   The plant and potting material is removed from the container and
     placed in the excavated hole.  (In the case of peat pots, the plant
     and potting material are not removed.  However, any portion of the
     peat pot extending above the potting material surface must be
     removed.  This prevents a loss of soil moisture from around the
     roots of the plant via a "wick effect".)

3.   The top surface of the root ball should be at or slightly below the
     level of the surrounding soil.

4.   The native soil is compacted around the plant.  Once the plant is
     in place, those having basin areas should receive about 2 liters of
     water.

In the' case of bare root seedlings, essentially the same procedure is
followed with the exception that the hole in. which the seedling is placed
                               197

-------
PROPER  PLANTING OF  CONTAINER  PLANTS
           PEAT  POT - BREAK OFF  RIM OF POT
           ABOVE SOIL LINE PRIOR  TO 'PLANTING.
           DEEP  TUBE-TO REMOVE  PLANTS,  INSERT
           CONTAINER AND KNOCK  RIM  AGAINST A
           ROCK  OR SHOVEL. PROTECT  PLANT  FROM
           INJURY.
           BOOK  PLANTERS-  PLANTS ARE  GENTLY
           REMOVED AFTER  OPENING  THE  BOOK.
           PLANTERS  ARE FRAGILE,  BUT REUSEABLE.
                 PLANTING

   TOO SHALLOW
                            TOP  OF ROOTS
                            MUST BE JUST
                            BENEATH SOIL
                            SURFACE.
                            TAMP  FIRMLY.
      TOO  DEEP
                               STATE- OF  CALIFORNIA
                         STATE WATER RESOURCES CONTROL BOARD
                                CONTAINER

                                   PLANTS
                        DEMONSTRATION  OF EROSION AND
                         SEDIMENT CONTROL TECHNOLOGY
FIGURE NUMBER
 vrn-31 .-
                    198

-------
must be sized to accept the full  root system.  The planter should be
careful not to compress the root  system against the central stalks as
soil is replaced around the plant.

Fertilizer is not required when planting  the bare root or contained
shrubs.  The grasses require about one gram of 16-20-0 fertilizer placed
at the bottom of each hole.  Care should  be taken to mix fertilizer into
the soil at the bottom of the hole to avoid burning the plants.  If
planted early in the spring or  fall, the  plants should not require con-
tinuous watering.  However, greater success can be assured if water is
available when the plant is initially placed in the ground and for subse-
quent watering until the plant  is established.  Once the root system of
a native drought-tolerant plant is well established (1-2 months),
further artificial watering should not be necessary.

Planting Costs

Plants for erosion control may  be obtained from commercial growers if
substantial @g-*l% year) advance notice can be given (see Appendix A).
Native shrubs vary widely in costs.  If large quantities (1,000 or
greater) of plant materials in  7.5-centimeter peat pots, or equivalent
size, are ordered in advance, the cost per plant may be as low as $.50
per delivered plant for the more  common species.  Bare root tree seed-
lings acquired from the California State  Division of Forestry plant
nurseries can be obtained for as  little as $.05 per plant including
transportation.  Although data  is not readily available, it is likely
that grass seedlings in 7.5-centimeter peat pots may be obtained for as
little as $.10 per peat pot. For more detailed information on plant
propagation costs refer to Appendix A.

Over 20,000 plants were planted at Rubicon Properties in the fall of
1976 and spring of 1977.   Individual planting rates varied from 20 plants
per hour to over 50 plants per  hour.  With reasonably good conditions
(i.e., moderate slopes and cool weather), sustainable rates of about 40
plants per hour for shallow containers and 30 plants per hour for bare
root trees (large root systems) might be  expected.

Equipment required for planting operations involve, at a minimum, a
half-ton pick-up truck and various hand tools.  The hourly equipment
cost is about $3.50 per hour for  a five-person work crew.  Plants at the
Rubicon Properties project site,  at an average, were placed 2-4 plants
per square meter.  The planting unit cost data is summarized in Table
VIII-6.

                      3.   Seed  arid Fertilizer

The ideal objective of revegetative erosion control is to ultimately
produce a vegetative cover which  is native and blends naturally with the
surroundings.  Most erosion control seed mixtures contain nonnative
grasses with the fertilizer added separately..  Legumes, native shrub,
and wildflower seeds,  may also  be added.  The primary role of the non-
native fertilized grass seeding is to provide a quick, temporary (1-5
                               199

-------
                                TABLE VIII-6

               EQUIVALENT COSTS OF PLANTS FOR EROSION CONTROL

                                                UNIT COST ($/PLANT)

   PLANT TYPE               MATERIALS      EQUIPMENT      LABOR*    TOTAL

                              .500           .047         .406      .954

                              .050           .035         .542      .627

                              .100           .047         .406      .554
Shrubs

Bare Root Seedlings

Grass Plant Clones
   *Note:  Equivalent labor cost is assumed to Be $16.25 per person-hour.
     years), means to stabilize eroding soil.   This allows development of slow
     growing, less nutrient-dependent native  species, which otherwise would
     have been unable to gain a "foothold".

     A wide variety of seed and fertilizer is available for erosion control
     plantings.  The seed and fertilizer used for this erosion control demon-
     stration project are shown in Table VIII-7.  The individual species
     which were chosen for use were based upon the success of previous seed-
     ings conducted in the Lake Tahoe-Sierra  Nevada environment C46, 53, 54).
     Those species listed in Table VIII-7 are described below.
Grasses
     *Luna* pubescent wheatgrass CAgropyrdn'trichophorum  'Luna*).  'Luna*
     pub'escent wheatgrass shows more seedling vigor than  the other grasses
     and, except for 'Tegmar*  or 'Oahe' intermediate wheatgrasses, has estab-
     lished better on droughty or otherwise difficult sites.  'Luna'
     rhizomatous and matures early Cat about 60 centimeters).
                                                                 is
     'Tegmar'  intermediate wheatgrass  CAgropyron iritermedium 'Tegmar').
     'Tegmar*"  intermediate wheatgrass  is  slightly inferior to 'Luna1 pubescent
     wheatgrass in establishment but superior to other intermediate wheat-
     grasses.   It could be substituted for  'Luna' pubescent wheatgrass.
     'TegmarT  intermediate wheatgrass  is  rhizomatous, stays green longer, and
     is shorter than *LunaT.

     'Durart hard fescue GFestuca xiviria ^dttrius-ciilal.  'Durar* hard fescue is a
     non-»rhizomatous short grass.

     "Potomac' orchard grass  CDactylis glbmerata'Potomac*),,  'Potomac' orchard"
     grass is-  a fast growing, non-rhizomatous, short grasX.
                                     200

-------
     'Manchar' smooth brome (Bromus  inermis  'Manchar').   'Manchar' smooth
     Brome, a rhizomatous grass,  has deep  green foliage and broad brown seed-
     heads which add color and contrast  to mixtures with  the above grasses.

     'Lincoln' smooth brome (Bromus  inermis  'Lincoln').   'Lincoln' smooth
     brome is rhizomatous, and is similar  to  'Manchar' described above.

'Luna' and 'Tegmar' wheatgrasses  may be  difficult to obtain commercially.
Orders for these species should be placed  well in advance.  If necessary,
more available rhizomatous substitutes include 'Oahe*  intermediate wheatgrass,
'Topar' pubescent wheatgrass,  and western  wheatgrass.  Rhizomatous species
are highly recommended due to  their  ability  to extend  and increase the per-
centage of plant coverage from year  to year on difficult  sites where species
relying solely on seed production face severe limitations.

Other nonrhizomatous, fast growing species such as 'Potomac' orchard grass
provide rapid stabilization of problem sites  until other  species have an
opportunity to become established.

Grass seed mixture application rates used  as  part of the  erosion control
demonstration project have ranged from 40  to  86 kg/hectare.  A rate of 40
kg/hectare should be sufficient if the seed is incorporated into the soil and
then mulched.  However, a rate of 80 kg/hectare or higher is recommended if
the seed is placed on the soil surface or  applied with the mulch.  The "best"
results at the Northstar project  site were achieved with  a hydromulched plot
which was accidentally seeded  at  a rate  of 260 kg/hectare!

Legumes

     'Lutana* cicer milkvetch  (Astragulus  cicer 'Lutana').  Cicer milkvetch is
     a rhizomatous spreading legume  which  develops slowly but can grow up to
     50 centimeters in height.
     'Dutch' white clover (Trifolium repens).
     low growing rhizomatous  legume.
'Dutch' white  clover is a
     'Cascade' Trefoil (Lotus  corniculatus  'Cascade').  'Cascade' Trefoil
     is a bushy legume reaching heights of up to 60 centimeters and produces a
     colorful yellow flower.

Legumes provide some nitrogen  to other plants, such as the grasses, which
would otherwise require continuous  fertilization on the more sterile sites.
In many instances,  legumes  are difficult to grow at higher elevations and at
dry sites.  All legumes planted from seed require inoculation with the proper
Rhizobium bacteria.  If legume seeding is specified using a hydraulic system,
the legume seeds should be  pellet-inoculated (22).

Legume seed mixture application rates used as part of the erosion control
demonstration project have  ranged from 12 to 25 kg/hectare.
                                    201

-------
                                TABLE VIII-7

           PERCENTAGE COMPOSITION OF SEED AND FERTILIZER MIXTURES
                  USED AT THE EROSION CONTROL PROJECT  SITES
                                                   Grass  Seed Mixtures
GRASSES
Luna puBescent wheatgrass
Tegraar intermediate wheatgrass
Durar hard fescue
Potomac orchard grass
Manchar smooth brome
Lincoln smooth Brome
LEGUMES
Lutana cicer milkvetch
Dutch white clover
Cascade trefoil
SHRUBS AND WILDFLOWERS
Artemisia tridentata
Purshia tridentata
Oenotheria hookeri
Linum lewisii
Gilia leptantha
Nemophila maculata
Eschcholzia calif.
FERTILIZERS
16r-20<-0 (fast)
7r-40^6 (slow-pellet)
38-Or-O (slow-pellet)
0-20-0 (fast)
      B
             D
11   11   16     40
66   56   42     40
17   —   16
     33   16     20
 6   -_   —
                                                  100 100   100   100
Legume Seed Mixtures
A     B     C     D
57
24
19
50
50
67
11
22
50
50
                                                  100 100    100   100
ShruB Seed Mixtures
  A      B      C
 10
 30
 *>n
 ^L. \J
 10
 i n
 JL \J
 10
 10
   100
    100
                                                  100
        100
          100
Fertilizer Mixtures
  X      Y      Z
100
   45
   55
               40
               60
                                                  100
       100
         100
                                     202

-------
Shrubs and Wildflowers
     'Basin Sagebrush' (Artemesia tridentata).  'Basin Sagebrush' is a common
     drought tolerant shrub found in desert and mountainous regions of the
     west.

     'Bitterbrush1 (Purshia tridentata).   'Bitterbrush' is a drought tolerant
     shrub with bright yellow flowers,  common to  the  eastern slope of the
     Sierra Nevada range.

     'Hooker's Evening Primrose1  (.Oenotheria hookeri) .   'Hooker's' Primrose
     is a wildflower with large yellow  petal usually  found in moist areas
     below 2,000 meters elevation.

     'Western Blue Flax' (Linus perenne lewisii).   'Western Blue Flax' is
     a wildflower with light blue petals, usually  found in dry, open exposures
     up to 4,000 meter elevations.

     'Showy Blue Giliat (Gilia leptantha ssp. purpusii).  'Showy Blue Gilia'
     is a wildflower with pinkish violet flowers,  usually found in moist
     open exposures up to 2,500-meter elevation  in the southern Sierra Nevada.

     'Fiyespot' (Nemophila maculata).   'Fivespot'  is a sprawling wildflower
     with white flowers having large purple  spots, usually found in moist
     areas of the western Sierra Nevada range below 2,500-meter elevations.

     'California Poppy' CEschscholzia californica).  The 'California Poppy',
     the California state flower,  is a wildflower with bright orange to yellow
     petals, common in open, dry places below 2,500-meter elevations.

Several other species of shrubs and  wildflowers native to the Sierra Nevada
range are also available commercially.   Sage and bitterbrush were chosen
because of their drought tolerance.   The various colorful wildflowers were
chosen more for aesthetic reasons  than as a  practical means to control ero-
sion.  Prior to the erosion control demonstration project, little work has
been done demonstrating the feasibility of establishing these types of plants
at such severe sites as are found within the demonstration project sites.  The
California poppy has shown the greatest promise  as a colorful additive to
difficult erosion control sites.

Shrub and wildflower mixture application rates used as part of this demonstra-
tion project have ranged from .2 to  4.5 kg/hectare.

Fertilizers

     16-20-0.  The 16-20-0 fertilizer used was a fast release fertilizer
     which dissolves rapidly in water.   It has a good balance of nitrogen,
     phosphorus, and sulfur.   All  three are  deficient for herbaceous vegeta-
     tion in the vicinity of Lake Tahoe C46) .

     7-40-6.  The 7-40-6 fertilizer used, Mag Amp, was a slow release fer-
     tilizer in pellets (approximately  one centimeter in diameter) which
                                    203

-------
     dissolve very slowly in water.   The large pellets can clog a hydroseeder
     and lead to higher application  costs.  It contains no sulfur.

     38-0-0.  The 38-0-0 fertilizer, or  urea formaldehyde, was a slow released
     fertilizer in pellets Capproximately 0.3 centimeter in diameter) which
     is broken down slowly in  the soil.  It contains only nitrogen.

     Q-20-0.  The 0-20-0 fertilizer, or  single super phosphate, is a fast
     release fertilizer, containing  phosphorus and sulfur, used to supplement
     the urea formaldehyde.
                                                                f
There is a considerable degree of controversy surrounding the use of fertil-
izer, particularly within the  Lake Tahoe Basin.  Overfertilization creates a  •
potential for the fertilizer to enter surface waters by means of storm-water
runoff.  Fast release fertilizer, such as 16-20-0, is of greatest concern due
to its solubility.  The level  of fast release fertilizer use, as part of the
erosion control demonstration  project, has been held to about 280 kg/hectare
of 16-20-0.  The levels of fertilization used at the erosion control demonstra-
tion site contains approximately one-tenth the nitrogen which is normally
applied to a typical golf course in  a single season.  A rate of 280 kg/hectare
for 16-20-0 is one-half the minimum  rate normally recommended for erosion
control seedings elsewhere in  California (55).

Even at 280 kg/ha, if a 2.5 centimeters  per hour rainstorm were to wash away
all the 16-20-0 fertilizer applied to one hectare, the result would be 250,000
liters of runoff with a nitrogen concentration of approximately 180 mg/1.  The
California Regional Water Quality Control Board, Lahontan Region, has estab-
ished a .20 mg/1 total nitrogen water quality objective for Lonely Gulch Creek,
a creek receiving runoff from  the Rubicon Properties project site.  A discharge
of 250,000 liters of water with a total  nitrogen concentration of 180 mg/1
would be a clear violation of  this water quality objective.  If any more nitro-
gen than 1/1,000 of that applied as  fertilizer were to be carried in 2.5 centi-
meters of runoff water, there  would  probably be a violation of water quality
objectives for Lonely Gulch Creek.

Fortunately, the limited monitoring  conducted thus far at the erosion control
project sites has not indicated any  increase in nitrogen concentration which
could be attributed to erosion control fertilization, possibly because much of
the fertilizer is bound to the soil  particles.  Well designed erosion control
measures prevent any significant overland flow which could wash fertilizers
or soil particles into surface waters.   Well stabilized soil with incorpor-
ated nutrient materials will not be  easily eroded or deposited in surface
water drainages.

On a few plots, slow release fertilizer  (7-40-6) was applied at a rate of
280 kg/hectare along with the  fast release fertilizer  (16-20-0) at 280 kg/
hectare.  The success of the slow release fertilizer in sustaining long-term
growth of the seeded plant species is not ascertainable at this time.

In most instances, limiting fertilization to slow release fertilizers would
not provide nutrients to the plant when  most needed, immediately after germi-
nation.  Use of a slow release fertilizer should be combined with a faster
                                    204

-------
release type.  If inexpensive labor or equipment is available, the best
approach to fertilization of  seeded erosion control sites is to conduct low
level applications of fast release fertilizers on an "as needed" basis.  This
is likely to be the least expensive, least polluting, and best plant growth
practice.

High fertilization rates may  be detrimental to the growth and development of
native plant species in and around the Tahoe Basin.  Many native plant species
have developed abilities to survive in nutrient deficient environments.  These
native plants have difficulty competing with artificially fertilized nonnatives.
Figure VXII-32 s-hows an area  of a topsoiled roadcut at the Northstar project
site.  The native manzanita shrubs (Arctostophylos patula) seen in the photo
developed from seeds contained naturally in the topsoil.  The grasses seen in
the right half of the picture are the results of a hydromulched grass seeding
experimental, plot on a portion of the topsoiled area.  In the portion of the
topsoiled area which was hydromulched, seeded, and fertilized, there is less
than 50.percent of the manzanita growth which is occurring in the "topsoiled-
only" portion on the left. The picture was taken in 1977, six years after the
topsoiling and four years after the grass seeding.

Seed Placement

Four basic methods for the placement of seed and fertilizer were used as part
of the erosion control demonstration project.  These included:
       Figure VI5I--32,  Competition between artificially seeded plant
       materials and native shru&s on a top^soiled slope at Northstar.
                                    205

-------
1.   "drilling" on a level site by means  of  a range drill

2.   manual application of seed and fertilizer, followed by manual raking
     prior to a mulch application

3.   hydraulic seeding and fertilization  with hydroseeding equipment
     prior to an application of mulch

4.   application of seed,  fertilizer, and mulch conjunctively in a one-
     step hydromulching operation

The highest germination percentage and the best results are obtained
when the seeds are covered with soil.  This  may be achieved on level
surfaces by use'of a range drill,  as shown in Figure VIII-33, or a
similar device.  On steeper sites,  or if  a drill is not available,
seeding may be done by manually broadcasting, ;then lightly raked or
Buried by dragging a chain over the seeded area.  Grass seeds should
never be covered more than one centimeter, except on decomposed granite
where they may be covered  to a depth of 2 to 3 centimeters.  Once the
seed is in place, the ground surface should  be mulched.  Best results
may be expected from this  method.

If hydroseeding equipment  is available, the  seed may be hydraulically
applied to the soil surface in a water slurry with 20 metric tons of
mulch/hectare for visual metering  and seed cushioning.  An application
of mulch over the hydraulically seeded slope is then required.
      yKE!^33,  Seed and £e-rt^li^zer placement on a level unvegetated
                  area By means of a range drill.
                                206

-------
If an economical and efficient operation is required, the mulch, seed,
and fertilizer may be hydraulically applied in a one-step operation.
For a more complete discussion of hydroseeding and seed application in
mulch, see the section on hydromulching.  Generally poorer results are
obtained using this method  due to the fact that a large percentage of
the applied seed is suspended in the mulch and not in contact with the
soil.

The consequences of foot traffic or other disturbances on a seeded
slope is somewhat inconclusive.  In some instances, foot traffic on
a seeded slope appears to enhance survival by incorporating the seed
into the soil.  In other instances foot traffic on steeper areas, par-
ticularly those with exposed hardpan outcrops, can dislodge the seed and
cause it to be sloughed to  the toe of the slope.

Irrigation.  Repeated irrigation of a seeded area will enhance seed
germination and plant survival.  If irrigation facilities are not avail-
able, seeding should only be conducted in the early spring or late fall
just prior to the appearance of  snow.  Without a backup irrigation sys-
tem, a seeded slope is at the mercy of the weather.  If an irrigation
system is available, the water must be applied very slowly to guard
against erosion induced by  runoff.  The seedbed must be kept continuously
wet until the seeds sprout.

An irrigation system which  could deliver 2.5 centimeters of water to
a 1.0 hectare seeded area once every  two weeks at a rate of .5 centi-
meter per hour would cost approximately $3,000 per hectare for instal-
lation.  An additional expenditure of approximately $1,000 per month
the installation costs ($1,500)  involves materials which would be reuse-
able elsewhere.  Assuming that irrigation would be required for two
months  Ca total of 10 centimeter water), irrigation cost would total
approximately $5,000 per hectare.

In the Lake Tahoe Basin, early spring seedings benefit from the high
soil moisture remaining for some time after snow pack melt.  Seedings
conducted late in the year may suffer from frost heaving, particularly
if a less than average snow pack exposes  the seeded slope to repeated
freezing and thawing during portions  of  the winter.  Without instal-
lation of an irrigation system,  repeated reseeding of critical areas may
be required.  In most instances, reseeding should not be required more
than once.  With good weather conditions  and good timing neither reseed-
ing nor an irrigation system would be required.

Seeding and Fertilization Costs.  Individual varieties of seeds vary
greatly in cost and may fluctuate from season  to season and year  to year
depending upon market conditions.   Costs may range  from $1.20 per kg  for
Potomac Orchard grass to $3.65 per kg for Durar Hard Fescue.  At  the
project sites, a wide variety of combinations  of various  grass  seed,
legume  seed, and shrub seed mixtures were applied.   For the seed unit
cost  estimates, various seed mixture unit costs were averaged to arrive
at the  following estimated values:
                                207

-------
     Grass Seed Mixture
     Legume Seed Mixture
     Shrub Seed Mixture
$ 2.60/kg
  6.00/kg
 19.00/kg
Fertilizer costs are estimated as follows:
     16-20-0
     Mag-Amp
     38-0-0
     0-20-0
 $ -,193/kg
  1.203/kg
   .638/kg
   .180/kg
TABLE VII I- 8
COMPARATIVE LABOR AND EQUIPMENT COSTS FOR VARIOUS DIRECT
SEED AND FERTILIZER APPLICATION TECHNIQUES
(does not include cost of seed, mulch or fertilizer)
DOLLARS/HECTARE
LABOR EQUIPMENT
Applied with wood fiber 	 	
hydromulch
Hydroseeding followed by 	 	
hydromulching at 2800 kg/ha
Hydroseeding followed by — — 	
hydromulching at 5600 kg/ha
Hydroseeding before other — — 	
mulch types
Hand seeding at 'commercial $520/ha $25/ha
rate C$13/hr + 25%)
Hand seeding by county - $320/ha $25/ha
workers rate C$10/hr)
Hand seeding by CCC $160/ha $25/ha
workers C$5/hr)
Seed and fertilizer $130/ha $40/ha
applied with range drill
*Note: These costs derived from CalTrans contracts.

TOTAL
$ 0/ha*
$ 79/ha*
$ 48/ha*
$348/ha*
$645/ha
$345/ha
$185/ha
$170/ha

                                208

-------
Comparative unit labor and equipment  costs of these various seeding
techniques are shown in Table VIII-8.  Costs for seeding utilizing
hydromulching equipment are derived from Figure VIII-35.

The additional labor and equipment cost  of simultaneous application of
seed material and fertilizer with the hydromulching process is considered
to be negligible.  However, hydroseeding prior to mulching can increase
the unit labor and equipment costs.   If  hydroseeding is conducted prior
to hydromulching, a moderate increase in unit cost may be expected due
to the additional use of the hydromulching equipment per unit area.  If
hydroseeding is conducted prior to a  mulching technique other than
hydromulching, the increase in unit cost can be significant due to the
required use of hydromulching equipment  which otherwise would not have
been necessary.  Hydroseeding is assumed to be conducted by applying
wood fiber mulch at .20 metric tons per  hectare  (for visual metering and
seed cushioning) and water at 10,000  liters per hectare with the appro-
priate amount of seed and fertilizer. Hand seeding and raking can be
accomplished at a rate of approximately  four person-days per hectare.

                      4.  Mulching Techniques

Introduction.  Several methods of seeding  and mulching are available
for vegetative erosion control.  By  combining various mulch rates and
techniques, seeding rate and techniques, fertilizing rates and techniques,
and tackifier rates and techniques, many methods with varying costs and
degrees of effectiveness are available for use.  Obviously, a project
with time, space, and funding constraints  cannot possibly demonstrate
such a wide variety of mulching and seeding  techniques.  Rather, an
attempt was made to choose those types of  methods which,  (1) were readily
available for use in and around the Lake Tahoe  Basin,  (2) appeared to be
relatively inexpensive, and  (3) appeared to  offer  the  greatest chance of
successful revegetation of steep, severely eroding sites.

Basically, the seeding and mulching techniques  demonstrated as part of
this erosion control demonstration project fall into  three general
categories:

     a.   hydromulch ing
     b.   straw mulching
     c.   mulch nets and blankets.

In the  following sections,  these basic  techniques and related variations
are described and  discussed,  particularly as relating to their  cost,
effectiveness, and manner  of use  at  the project demonstration sites.

Cost Estimating  Procedures.   The  cost estimating procedures  and assump-
 tions  listed  at  the beginning of  this section were used in developing
 the cost data pertaining  to se.eding  and mulching techniques.   Information
 is based upon first-hand  experience  at  the erosion control demonstration
 sites,  communications  with the California Department of Transportation,
 and communications with seeding and  mulching contractors local  to the
 Tahoe Basin and vicinity.

                                209

-------
           5.  Wood Fiber Hydro seeding  and Hydromulching

Hydroseeding ±s a method of applying seed (and fertilizer) to soil in a
water slurry.  Hydromulching,  as  used in tMs text, refers to the method
of applying wood (cellulose)  fiber (with or without seed and fertilizer)
to the soil in a water slurry (see Figure VIII—34).  Hydroseeding is an
effective'and a relatively inexpensive  means of applying seed to a slope
for revegetation.  It requires a  minimum labor force, but a fairly large
capital investment in equipment.   With  rare exceptions, only commercial
enterprises specializing in hydroseeding or hydromulching are available
to conduct such an operation.  The cost of hydroseeding equipment covers
a wide spectrum from a few thousand dollars for 250 gallon units up to
$100,000 for self powered 5,000 gallon  units.  Advantages of hydroseed-
ing include uniform distribution  of seed and fertilizer, access to steep
slopes or areas too wet to sustain either pedestrian or heavy equipment
traffic, and, if only commercial  labor  is available significantly lower
cost than conventional hand seeding.  Disadvantages include the necessity
of a paved or otherwise firm surface near or adjacent to the area to be
seeded, a readily available water supply, a high degree of capital commit-
ment, and an inability to place the seed into the  soil.

A wide variety of seeds, including grasses, legumes, shrub, and tree
seeds may be used with the hydroseeding process.   Large seeds (such as
sugar pine) and extremely fragile seeds should not be used.  The inclu-
sion of legume seeds is not recommended unless the inoculant coating is
durable (56).  Poor success with  legumes in the hydroseeding process
                                ; :?$/yp&$'.; / >,t 7 /   -' '
Figure VIII-34.  Wood fiber hydromulching with seed and fertilizer
                     in a one^step operation.
                                210

-------
probably due to the extreme dilution of the inoculant when added to
the mulch slurry.  Grass, legume,  and shrub seeding rates demonstrated
at the project sites varied from 56 to 112 kg per hectare (50 to 100 Ibs
per acre).  These rates, or even higher rates,  are recommended for use
with the hydromulching process.

The inclusion of a mulch when hydroseeding vastly improves the probability
of successful seed growth and plant development.  Generally, the mulch
used with hydroseeding equipment is composed of fine wood fibers which,
when agitated, disperse rapidly  in water to form  a uniform slurry.  Wood
fiber mulch is usually manufactured from aspen  or alder wood chips with
dispersing agents and dyes added.   Wood fiber mulch manufactured from
recycled waste paper is also available.  Although this product is less
expensive and less resource exploitative, other investigators have shown
that it produces a less effective  mulch cover (57).  Other fibers com-
posed of dairy waste fiber, ground straw, ground  newsprint, recycled
office waste, rice hulls, seed screenings,  and  cubed alfalfa may be
available, but generally do not  perform as satisfactorily as virgin
wood fiber.  Advantages of wood  fiber include:

     -    formation of a strong, flexible mat which holds the seed and
          fertilizer in place until the seed has  germinated
          insulation of seed and soil from solar  radiation
     -    contains no weed seeds or other foreign seed
          uniform application assisted by non-toxic dyes which fade upon
          exposure to light
          cushioning of seed against damaging action of the mulching
          unit's pump

Wood fiber mulch is typically applied at rates  ranging from 1,000 - 2,000
kg per hectare.  Usually 1,580 kg  per hectare is  specified.   When rates
of about 2,000 kg per hectare or lower were demonstrated as part of this
erosion control project on adverse sites,  very  poor results were obtained
compared to that achieved with higher mulch rates.  On the severely
sloping (2:1.or greater), dry, exposed road cut and fill slopes found
within the demonstration project sites,  satisfactory results have been
achieved only with mulching rates  above 2,800 kg  per hectare (2,500 Ibs
per acre).  It appears that even greater success  can be achieved with
mulching rates approaching 5,600 kg per hectare (5,000 Ibs per acre).
It should be noted that such high  rates are only  recommended for the
most severe erosion sites.  Lower  mulching rates  should be sufficient on
lesser (less than 2:1) slopes which are sufficiently moist or shaded.
As is noted later in this report,  due to economies of scale, a 100 per-
cent increase in wood fiber mulching rate over  a  one-hectare area would
normally increase the total cost of the operation only 30 to 40 percent.

Various commercially available chemical additives, both natural and
synthetic, are advertised to hold  mulch in place, promote germination,
hold moisture, and reduce soil erodibility.  Evidence from previous
investigations (58) indicate that  these additives, in most instances, do
not significantly aid plant growth.   Polyvinyl  acetate (PVA) and styrene
butadiene (SBR) were the only wood fiber mulch  additives demonstrated as
                               211

-------
     part of this project.  The chemical additives transformed the flexible
     wood fiber mulch covering to a stiff plate-like covering which was sus-
     ceptible to  frost heaving and cracking.  As a result, in most test plots
     where such additives were used, there was substantially less seed germ-
     ination and  growth.

     Wood fiber mulch may be purchased with a organic tackifier already con-
     tained in the mulch  (approximately 3 percent by weight).  A substantial
     number of plots  have been tested using pretreated wood fiber mulch at the
     Rubicon erosion  control demonstration site.  Initial evaluation,  however,
     indicates that such pretreated mulch produces the same results as
     untreated mulch.

     Hydromulching Costs

     Mulch costs  are  highly dependent on the quantity of mulch purchased.
     It is furthermore assumed that a commercial operation would purchase
     wood fiber in 27 metric ton carload lots, which would allow the mulch
     to be purchased  at the lowest possible price.  In addition, it assumed
     that such carload prices are F.O.B. the San Francisco Bay area and that
     an additional $33.00 per metric ton would be required to transport the
     XTOod fiber to the Lake Tahoe area.  The unit costs for wood fiber, thus
     derived are  as follows (.to the nearest dollar) :
          a.
          b.
          c.
          d.
Conwed
Conwed 2000  (w/tackifigr additive)
Weyerhauser Silva Fiber
Average for Untreated Mulch
Dollar/Metric Ton*

       $200
        329
        162
        181
     Up to a 60 percent increase in unit purchase price may be expected if
     wood fiber mulch is purchased in 1 ton rather than 30 ton lots.

     Unit hydromulching costs used in this report are derived from data
     extracted from current  CalTrans contracts throughout California.   The
     CalTrans contract data  was available in the form of wood fiber mulch
     "in-place" costs for various contracts ranging in size from .14 hectare
     to 36.15 hectares. These costs include all materials, labor, and equip-
     ment required for the mulch placement, but do not include materials,
     equipment, and labor required for fertilizing, seeding, or chemical addi-
     tives.  CalTrans contracts specify 1.7 metric ton per hectare application
     rate for wood fiber mulch.  The total cost, area covered, and mulching
     rate was used to determine the cost per unit of mulch for each of the
     various contracts. This data, after a format adjustment to dollars/
     metric ton versus metric tons, is shown in Figure VIII-35.
*Prices as of June 30,  1976
                                    212

-------
It is assumed,in this  report, that the critical factor controlling job
cost is the total amount of mulch applied rather than the total area
covered.  Assuming easy accessibility, it should not be significantly
more expensive to cover 10 hectares with 5 metric tons of mulch than it
would to cover 1 hectare with the same total amount.  Thus,  the cost
data are presented in  cost per unit weight rather than cost  per unit
area.  Unit mulching costs may be readily obtained for a variety of
mulching rates.

Cost data reported elsewhere (41) and obtained through personal communi-
cations with private contractors closely corresponds to the  CalTrans
data.  Local contractors use as a practical "rule of thumb"  that 0.4
hectare (1 acre) mulched at a rate of 1,680 kg per hectare (1,500 Ibs
per acre) should cost  $600.  This value is within 4 percent  of the value
determined from the information in Figure VIII-35 with allowances for
seed and fertilizer costs.

Economies of scale, inherent in most equipment intensive endeavors, are
apparent from the data presented in Figure VIII-35.  For example, when
the amount of mulch applied is increased by an order of magnitude from
.68 metric tons to 6.8 metric tons, the unit cost is more than halved
from $882 per metric ton to $392 per metric ton.
                         HYDROMULCHING  COSTS
                          DOLLARS PER  METRIC TON
                                    VS
                               METRIC TON
                                     MULCH, LABOR,  and
                                     EQUIPMENT  COSTS
         LABOR and
         EQUIPMENT ONLY
                     .4   5   6   7   8   9   10   II
                     METRIC TONS  of WOOD FIBER MULCH
12   13
14   15
Figure VIII-35.   Wood fiber hydromulching labor and equipment unit
cost as a function of amount of mulch applied.  Based on CalTrans
                 contracts for first half of 1976.
                               213

-------
There may be some questions as to whether or not this data is applicable
to conditions found in and around the Late Tahoe Basin.   Unit costs are
partially dependent on the difficulty of application of wood fiber at
the construction site.  These difficulties generally derive from three
factors:

     a.   a readily accessible water supply
     b.   maneuverability of equipment
     c.   accessibility to job site

The first factor, water supply, should not be a major difficulty in and
around the Lake Tahoe Basin.  Arrangements may be made with the various
water districts to tap the water supply system via  fire hydrants in the
towns, villages, developments, and subdivisions throughout the Tahoe
area.  Indeed, a majority of erosion problems which may be controlled
through hydromulching exists in the form of oversteepened cut and fill
slopes adjacent to roadways within these urbanized  areas.   Nevertheless,
the use of hydromulching in more remote areas may require the use of
water trucks, which would significantly increase the unit costs depicted
in Figure VIII-35.

The second factor, maneuverability, may pose significant  problems in
steep, switchback, and narrow roadway areas, particularly  if the equip-
ment used is trailer-mounted rather than truck-mounted.   However, in
most instances, the equipment is likely to be large capacity (greater
than 5,500 liters) truck-mounted units which should be able to negotiate
most paved roadways in mountainous regions, such as those found in the
Lake Tahoe area.

The third factor, accessibility, should not be a problem  in the Lake
Tahoe Basin or elsewhere in urbanizing or urbanized areas  of California
and Nevada.  Several hydromulching contractors are  located within a one
to two hour drive from the Lake Tahoe Basin.

The following hydromulching costs per unit area are derived from Figure
VIII-35.

     a.   2.8 metric tons/hectare C2,500/lbs/acre)  - $967/hectare
     b,   5.6 metric tons/hectare ('5,000/lbs/acre)  - $l,353/hectare

These unit area costs reflect only the cost of labor,  equipment, and
overhead, not the cost of materials (mulch, seed, and fertilizer).   The
estimated total cost of hydromulching at three representative applica-
tion rates is included in Table VIII-9.

                        6.  Straw Mulching

Straw is an effective and inexpensive mulch.  Straw mulch  is generally
applied either by a straw blower (Figure VIII-36) or by manual distri-
bution.  Advantages of a straw mulching operation over hydromulching
include:
                                214

-------


TABLE VIII- 9

HYDROMULCHING AND ' SEED COSTS


DOLLARS /HECTARE

LABOR & SEED &
EQUIPMENT MULCH FERTILIZER* TOTAL
Mulch
Mulch
Mulch
*Note
at 1680 kg/ha
at 2800 kg/ha
at 5600 kg/ha
:. Grass, legume, and
16-20-0 fertilizer
756 304 400
967 506 400
1,353 1,013 400
shrub seed mixture at 100 kg /ha.
at 280 kg/ha.
1,460
1,873
2,766

     -    ability to utilize manual  labor in difficult spots
          lightweight and easily maneuverable equipment
     -    lower capital investment for  equipment
          no need for readily  accessible water supply

However, unlike wood fiber hydromulch,  straw mulch must be held down
by a separate operation.  Straw mulch may be incorporated into the
ground by means of a crimper or a modified sheepsfoot roller.  The use
of a crimper or a modified sheepsfoot roller is limited to fairly level
or gently sloping terrain.  Straw mulch may also be held in place by
the use of chemical tackifiers or nets.  These incorporating and tacki-
fying techniques are more fully described in the next section of this
section.  Major disadvantages  of"straw  mulching include:

     -    separate applications of seed and fertilizer (usually manual)
     -    high incidence of weed seeds  or seeds of foreign plant
          materials (use of rice straw  significantly reduces the extent
          of this problem)
     -    application radius of straw blowing machine is severely
          limited, particularly under windy conditions
     -    need to incorporate  or tackify the straw with soil immediately
          after application, and
     -    higher cleanup costs
     -    very costly at sites not accessible by straw blowing equipment

Like hydromulching units, straw blowing machines vary greatly in size
and cost.  Generally, an operation with experienced personnel and a
large machine can be expected  to mulch  a large project at a rate of
about 2.0 to 2.5 tons per hour.
                               215

-------
Figure VIZX—36.  Straw mulch application to fill slope By means of  a
                     straw Blowing machine.
                     STRAW MULCHING  COSTS
                     DOLLARS PER  METRIC TON
                                VS
                            METRIC TON
                                    MULCH,  LABOR and
                                    EQUIPMENT COSTS
          LABOR  and
          EQUIPMENT COSTS
                 3456789   10
                      METRIC TONS OF STRAW  MULCH
12   13   14  15
 Figure VIXJ.T-37,  Straw mulch application laBor and equipment unit
 cost as a function of mulch applied.   Based on CalTrans contracts
                     for first half of 1976.
                               216

-------
Many different straws are available for use.  Straw used as part of
this demonstration project have included:   (1) rice straw, C2) Barley
straw, and (3) tall wheatgrass straw.  Rice straw was the most difficult
to use, as it was not chopped finely enough and tended to be distributed
from the straw blowing machine in clumps.   Rice straw does have the
advantage of not containing seed of drought tolerant, foreign plants
capable of surviving in high altitude mountainous regions of California
and Nevada.  Clean barley straw is easy to  use if it is not baled too
tightly.  Barley straw is likely to contain a significant number of
barley and weed seeds which may interfere and compete with the specified
seeds, although the barley seedlings may provide considerable initial
soil stabilization.  Barley, however, is not likely to reproduce at
higher elevations.

The straw tacking operation, described in the next section, should be
conducted immediately after application of  the straw, particularly if
applied during windy weather.  Untreated straw is very light and can
easily blow away.  Loose straw should be kept under control at all
times.  Situations can easily develop where loose straw combined with
sediment and other detritus can clog and block drainage ditches, swales,
gutters, drop inlets, and culverts. Cleanup operations must therefore
begin immediately after straw is applied and tacked to an erosion control
site.

Straw Mulching Costs.  Straw mulch costs are also highly dependent on
quantity purchased.  Straw used for the project ranged from $33.00 per
metric ton for 11 tons of rice straw purchased in 1975 to $25.00 per
metric ton for 4 tons of barley straw purchased in 1976.  Throughout
this report the cost of straw is assumed to be $30.00 per metric ton
F.O.B. Sacramento.  With assumed transportation costs to Lake Tahoe of
$15.00 per metric ton, the total price of straw for mulching is $45.00
per metric ton.

Straw mulching unit costs used in this report are derived from data
extracted from current CalTrans contracts.  The CalTrans contracts give
straw mulch "inplace" costs for areas ranging from  .32 to 176.06
hectares.  CalTrans specifications require  a straw mulch application
rate of 9.0 metric tons per hectare (~4 tons per acre).  The cost data
is presented in Figure VIII-37 (upper curve).

The lower curve in Figure VIII-37 depicts  the unit  labor, equipment,
overhead, and profits of the straw flowing  operation only.  The costs
of the mulch, $45 per metric ton, and  the  straw punching operation,
estimated to be one-third of the overall contract price  (41, 59), are
not included.

The basic unit area used to compare erosion control costs in this report
is 1 hectare  (2.47 acres).  It is felt  that most contractors equipped
for this operation would be willing to  submit a bid .on a project of this
size.
                               217

-------
     The straw mulching technique using straw blowing equipment is only effec-
     tive if the area to be mulched is within 20 to 30 meters of the available
     access road or surface.  In areas that  are unreachable using straw blow-
     ing equipment or in situations where inexpensive labor is readily avail-
     able, it may be more practical and less costly to use hand labor to spread
     the straw mulch.  Hand spreading labor  and equipment costs become competi-
     tive with a commercial straw blowing operation if hourly wages are $5.00
     per person-hour.  Straw mulching labor  and equipment equivalent costs are
     summarized as follows:
          a.   Commercial straw blowing  at 4.5
               metric ton/hectare
          b.   Manual straw spreading at 4.5
               metric ton/hectare
                                    $ 611/hectare

                                    $l,613/hectare
     Manual straw spreading equivalent  costs are based upon the assumptions
     listed at the beginning of  this  section, including the assumption that
     total labor costs are equivalent to  $16.25 per person-hour.  County road
     crews, on the other hand, could  manually spread straw at a cost of $963
     per hectare, and CCC workers  could manually spread straw for $517 per
     hectare.  The total estimated costs  of straw mulching and seeding, not
     including tackifier cost, is  included in Table VIII-10.
                                TABLE VIII-10
                      STRAW MULCHING AND SEEDING COSTS
Hydroseeded w/blown
straw at 4,500 kg/ha

Hand seeded w/manual
straw at 4,500 kg/ha
 LABOR &
EQUIPMENT

   960
 2,258
                                            DOLLARS/HECTARE

                                                      SEED &
                                            MULCH.  FERTILIZER*
202
202
400
400
                     TOTAL**
1,562
2,860
*Note:    Grass,  legume,  and shrub seed mixture at 100 kg/ha.
          16-20-0 fertilizer at 280 kg/ha.

**Note:   Tackifier costs are not included and should be expected to cost
          an additional $l,000/ha.
                                    218

-------
Hand-spread straw and mechanically blown straw differ in length and con-
tact with the soil.   Blown straw pieces  are shorter, sometimes split, and
lie down better.  Blown straw is generally easier to tack down, although
the longer hand-spread straw may be  superior for punching or crimping.

                  7.   Chemical Tackifying Agents

A wide variety of natural and synthetic  chemical mulch tackifiers and
stabilizers are available for use.   Some of the tackifiers may be
applied directly to  soils as a temporary stabilizer.

As discussed in the section on hydromulching, tacking of wood fiber
hydromulch has achieved limited success, particularly in regions prone
to severe frost heaving.  On the other hand, straw mulching in areas
which cannot be crimped or punched,  requires the use of a tackifying
agent.  Asphalt emulsions are commonly used as straw tackifiers.  Most
commercial operators find that such  asphalt emulsion sprays can be
difficult to use, quite messy, and aesthetically unpleasing when applied
to visible areas.  For these reasons,  representative samples of other
types of products which can be substituted for asphalt emulsions were
demonstrated as part of this erosion control project.  Tackifiers
demonstrated include:
                       •n
          Terra Tack II , a free-flowing powder produced from seaweed
          extracts.   This material is mixed with water and wood fiber
          mulch to form a slurry which is  applied as an overspray to a
          previously straw mulched site. When mixed properly, it
          polymerizes and, upon application,  forms  an insoluble network
          of binding membranes.
                       •n
     -    Terra Tack II  Super Concentrate,  an  experimental free-flowing
          powder similar to Terra Tack II  but which may be applied
          simultaneously with the straw mulch at  somewhat lower rates.
          This material is mixed with water  and a small amount of wood
          fiber to produce a slurry.  This product  proved ineffective
          and has been removed from the market.
                                   •n
          Ecology Controls M-Binder , a free-flowing powder produced
          from a plant gum (Plantago insularis).  This material has
          received limited use as a straw tackifier and was developed
          primarily as a wood fiber mulch binder and  soil stabilizer.
          It is mixed with water and wood fiber to  form a slurry which
          is applied as an overspray to the previously  straw mulched
          site.

          Styrene butadiene  copolymer emulsison (SBR) ,  a synthetic polymer
          in the  form of a white, milky translucent liquid which forms
          a thin  insoluble coating when applied and allowed  to  dry.
          This  material is mixed with water, a methyl cellulose
          modifier,  an  anti-foaming agent, and wood fiber mulch to  form
          a slurry.  When applied simultaneously with a straw blowing
                                219

-------
          operation, the amount of wood fiber mulch  should be kept to a
          minimum to prevent clogging of the apparatus.

          Wood fiber only, which is wood fiber applied as a tackifier
          with a hydromulcher at somewhat lower than normal rates.  On
          experimental plots at the erosion control  project sites,
          sprayed wood fiber mulch at 800 kg/ha was  as effective as any
          other tackifier which was used.
TABLE Till- 11
RECOMMENDED STRAW MULCH
TACKIFIER
•n
Terra Tack II
(powder)
Terra Tack IIR~
Super Concentrate
(poxtfder)
Ecology Control
M-Binder (powder)
SBR (Dow XFS
4163-L)
Asphalt
Emulsion
Wood Fiber
SHIPPED
WEIGHT
kg/ha
100
50
150
750
C745 1/ha)
4,400
(4,600 1/ha)
800
TACKIFIER
MODIFIER
kg/ha
(if any)
N/A
N/A
N/A
10.2
N/A
N/A
APPLICATION RATES
WOOD
FIBER
kg/ha
336
75
225
(up to
460)
N/A
800
WATER
liter/ha
14,000
5,340
8,750
4,250
N/A
16,800
SLURRY
liter/ha
14,000
5,340
8,750
5,000
4,400
17,000
The recommended application rates for these materials for steep and/or
difficult erosion control sites are shown in^Table VIII-11.  All the
materials demonstrated, except Terra Tack II  Super Concentrate, have
been tested by others (60)  under controlled conditions and at the rec-
ommended rates have a tacking strength comparable to asphalt emulsion.
Of the materials demonstrated, the powders appear to be the simplest to
use and require considerably lower shipping costs than do liquid tacki-
fiers, such as SBR or asphalt emulsion.   Both SBR and asphalt also appear
to require more involved cleanup procedures than do the powders.

Tackifying Costs.  The following tackifier materials costs are based upon
manufacturers' quotations,  including shipping but not wood fiber mulch
costs (if required):
                                220

-------
                                                      $Aha*
a.
b.
c.
d.
e.
f.
$6.35
$11.35
$ 4.65
$ .80
$ .20
$ .18
$635
$568
$698
$600
$880
$144
          Terra Tack^II
          Terra Tank  Super  Concentrate
          M-Binder
          SBR
          Asphalt Emulsion
          Wood Fiber only

     *    Cost per hectare for tackifier only based upon recommended
          application rates.   Lower unit costs may be achieved by
          purchasing materials in large quantities.

The two basic application methods for mulch  tackifiers are:  (1) simul-
taneous application with the mulch, and (2)  overspray application of
tackifier after the mulch is in place.  The  overspray tackifier appli-
cation method is usually accomplished using  a hydromulching unit.  An
asphaltic tackifier is applied with an asphalt rig or simultaneously
with a gear pump provided with most mechanical straw blowers.

It is estimated that the simultaneous tackifier application should only
increase the labor, equipment, and overhead  costs of the straw blowing
operation by about 10 percent.  This is particularly true if the commer-
cial enterprise is familiar  and experienced  with the methods involved.  A
two-stage application of tackifying agents can substantially increase the
labor, equipment, and overhead cost of the mulching operation.  The sepa-
rate, overspray addition of  the tackifier necessitates additional hydro-
mulching or spraying equipment and labor not otherwise required.  The
cost of overspraying a tackifying agent is assumed in this report to be
equivalent to the "per liter" cost of applying a wood fiber mulch slurry
minus the material cost of the mulch.  The wood fiber mulch slurry appli-
cation costs are based upon recent CalTrans  contracts and the assumption
that a commercial operation requires 21 liters of water for every kilo-
gram of wood fiber mulch applied (twenty 50  pound bales per 2,500 gallons
water) .

The unit labor, equipment, and overhead costs for tackifier application
via a hydromulching unit are summarized in Figure VIII-38.  For example,
application rates for labor, equipment, and  overhead cost per unit area
are as follows:

     a.   5,000 liters/hectare   -  $227/hectare
     b.   10,000 liters/hectare  -  $348/hectare

Due to economies of scale, a 100 percent increase in tackifier appli-
cation rate from 5,000 to 10,000 liters per  hectare results in only a
53 percent increase in labor, equipment, and overhead costs.  The total
estimated materials, equipment, and labor cost required for the instal-
lation of various tackifiers, based on  recommended application rates, are
listed in Table VIII-12, assuming a hydromulching unit is used to apply
the tackifier over the straw, as pictured in Figure VTII-39.
                           221

-------
              STRAW TACKIFIER  APPLICATION  COSTS
                          DOLLARS  PER  METER
                                  VS
                             METRIC TONS
                                 LABOR  and  EQUIPMENT
                                      COSTS  ONLY
     0   20  40   60   80   100  120  140 160   180  200  220  240  260  280  300
                     METRIC TONS OF APPLIED  WATER SLURRY

 Figure VIII-38.  Chemical taekifier application labor and equipment
  unit cost when applied as a water Base slurry with hydromulching
   equipment.  Based on CalTrans contracts for  first half of 1976.
Figure VJIZ~39,   Application of a chemical tackifier over straw nlulch
                  using hydromulching equipment.
                                222

-------
ESTIMATED


TACKIFIER
R
Terra Tack II
T>
Terra Tack II -S. C.
•D
M-Binder
SBR
Asphalt Emulsion
Wood Fiber only
TABLE VIII-12
TACKIFIER COST APPLIED

ALL
MATERIALS

$696
$582
$739
$683
$880
$144
OVER STRAW MULCH
' DOLLARS /HECTARE
LABOR &
EQUIPMENT

$426
$236
$321
$227
$720
$600



TOTAL

$1,122
$ 818
$1,060
$ 910
$1,600
$ 744
                    8.   Mulch Nets and Blankets

A variety of mulch nets and blankets  are available for placement over
seeded and fertilized areas.  These products  temporarily stabilize the
soil until the seeded plants have matured.  Use of mulch nets and blankets
can be advantageous in that experienced  commercial contractors and expen-
sive equipment are not required for their installation.  Nonetheless, the
mulch nets and blankets themselves are quite  expensive and require a
considerable amount of manual labor to install.  As-will be subsequently
shown., the use of mulch nets and blankets becomes economically competitive
in the Lake Tahoe-Sierra Nevada Region only if extremely inexpensive or
volunteer labor is available.  In addition there is no evidence at the
demonstration sites to indicate that  mulch nets and blankets are partic-
ularly more effective in establishing plant growth or providing temporary
soil stabilization than other,  less expensive mulching techniques.  A
possible exception would be in the case  of extremely sloping terrain
(.steeper than 1%:1).

The mulch nets and blankets demonstrated as part of the erosion control
project are the following:
                   •D
     -    Excelsior  Blankets,  a machine produced mat of curled wood
          excelsior which is evenly distributed throughout the blanket.
          The top side of each mat is covered with a biodegradable
          plastic mesh.  The mats are generally produced in rolls with
          a coverage of either 67 or  84  square meters each.  On slopes,
          the excelsior is  rolled out from top to bottom with one 15
          centimeter "U" shaped staple per square meter, as shown in
                               223

-------
Figure VIII-40.   Manual application of Excelsior'
                seeded and fertilized cut slope.
                                               R
blanket over a
         Figure VXII—40.   It is not necessary to dig check slots,  anchor
         ditches,  bury the ends of blankets, or provide extensive  slope
         preparation.

         Plastic Netting,  a rectangular "mesh of extruded, biodegradable
         plastic strands.   The netting generally comes rolled on a
         cardboard core in widths of 2.3 or 4.6 meters.  The total area
         covered by a 4.6  meter wide roll is 3,500 square meters.   The
         area to be covered must be a smooth raked surface, free of
         rocks, clumps of  plants, or anything else which prevents  the
         close contact of  the net to the surface.  The area must then
         'be seeded and mulched according to accepted practices and the
         plastic netting placed in lengths from the top to the bottom
         of the slope, overlapping 5 to 10 centimeters with the adjacent
         length.  Staples, 15 centimeters in length, are evenly distrib-
         uted at approximately one staple per square meter in a diagonal
         pattern.
                               224

-------
    Jute Mesh, a heavy netting of uniform open plain weave, loosely
    twisted jute yarn.  The jute mesh is furnished in 40 kilogram
    rolled strips which cover approximately 80 square meters each.
    The area to be covered must be  a smooth surface, free of rocks,
    clumps of plants, or anything else which would prevent close
    contact between the mesh and the ground surface.  The area is
    then seeded and fertilized according to accepted practices.  A
    light covering of mulch may also be applied.  The jute mesh is
    then rolled from the top to the bottom of the slope and held in
    place using 15 centimeter "U" shaped staples.  The mesh must be
    applied loosely without stretching.  The upper and lower ends
    of the mesh must be buried or otherwise firmly secured.  Where
    two or more lengths are applied side to side, an overlap o-f at
    least 10 centimeters must be made.  The staples should be
    evenly distributed in a diagonal pattern with approximately
    one staple per square meter. A steeply eroding road cut at the
    Rubicon Properties erosion control project site treated with
    jute netting is shown in Figure VIII-41.

    Paper Fabric, a combination of  thin paper strips interwoven
    with synthetic yarn mesh.  Both the paper and synthetic yarn
    are degradable.  A wide range of yarn-paper  durability and
    thickness is available depending upon specific site conditions
    and the need for slow or rapid  degradation of the fabric.  The
    paper fabric is furnished in widths of 1.5 or 3 meters.  The
    larger width is folded double and  shipped in rolls weighing
VJJI-41.  Jute netting applied to a seeded and fertilized slope.
                           225

-------
Figure VIII-42.  Manual application of paper fabric blanket over a
 seeded, fertilized,  and straw mulched severely eroding cut slope.
          approximately 36  kilograms each and is able to cover approxi-
          mately 325 square meters.  The area to be covered must be
          smooth, free of rocks,  clumps of plants, or anything else
          which would prevent close contact between the paper fabric and
          the ground surface.  The area is then seeded and fertilized
          according to accepted practices.  A light covering of wood
          fiber or straw mulch may also be applied to the slope face.
          The paper fabric  should be loosely applied to the ground sur-
          face, with no introduced tension or bridging above the ground
          surface.  Adjoining strips of paper fabric must be overlapped
          10 to 15 centimeters.  Staples, "U" shaped, and 15 centimeters
          in length are evenly distributed at one staple per square meter
          to hold the paper fabric in place.  A 10 to 15 centimeter deep
          check ditch should  be constructed 30 centimeters back from the
          slope crown and at  the  toe of the slope.  The top and bottom
          edges of the paper  fabric should be stapled in these check
          slots at 20 to 25 centimeter intervals and buried.  Lateral
          edges of the covered area should also be heavily stapled and
          buried to insure  against water channeling or lifting by heavy
          winds.

All of the above-mentioned  materials appear to perform well as mulch
nets and blankets.  Advantages of mulch nets and blankets over other
mulching methods include:

     —    direct physical attachment of mulch materials to soil surface
     —    can sustain moderate foot traffic once in place
                               226

-------
Figure VIII-430  Penstemon plants  sprigged through a slope covered with
paper fabric which helps retain the  soil moisture and inhibit erosion.
       -    after placement,  openings may be cut for sprigging plants as
            shown in Figure VIII-43
       -    usually durable and  long lasting
       *-    usually provides  some moisture retention
       -    less subject to foot or vehicle traffic as treatment is more
            obvious than hydromulched or straw tacked slope

  Disadvantages include:

       -    extremely high materials cost relative to other mulches
       —    extremely high manual labor requirement relative to other
            mulches
       -    foot traffic required for installation may dislodge previously
            placed seed on steeper slopes
       —    unsightly and may require eventual removal
                                                         •D
  Of all the mulch nets and blankets tested, the Excelsior  blanket and
  jute mesh , appear to provide the best coverage and adherence to the soil
  surface.  The paper fabric  appears effective in retaining soil moisture
  even on very dry, exposed slopes.  The plastic netting provides an
  inexpensive way to apply straw mulch to erosion control sites if straw
  blowing equipment is not readily obtainable and low cost manual labor
  is available.
                                  227

-------
160
u, "40
cc
||20
£100
D-
tn OH.
<
O
i 60
o
CO
£ 40
o.
o r\
c. M'
0

r>
L,

rAr






INSTALLATION TIMES FOR SELECTED

EROSION CONTROL NETTINGS 8 BLANKETS
KCEL
>ER




SIOF
-
. « « »_

	


	
r
. . «^.

n



A

. ^yg1

	 •


— -

.~-^-

3LAS


— '— •

. . »_;

TIC




.__• • r_!
*-

NET'





__ — •
'ING



JUTE





i-






-i •*







- •































2 3 4~ 5 6 7 8 9 10 II 12 13 14 15
DEGREE OF DIFFICULTY
SLOPE LENGTH (METERS) x SLOPE ANGLE (DEGREES)
Figure VIII~44,  LaBor requirements for  the manual installation of
          various erosion control nettings and blankets.
Mulch Net and Blanket Costs.   The costs  of mulch nets and blankets are
calculated based upon coverage of a  one-hectare job site.  Since the use
of nets and blankets is relatively uncommon in the Sierra Nevada—Lake
Tahoe area, it is assumed that these materials would not be purchased
in lots larger than that necessary to  cover each job.  Shipping costs are
dependent upon the location of the nearest distributor and the relative
weight per unit area of the material.  The following materials costs are
based upon information provided by various manufacturers and include
estimated shipping costs:
                        •n
          A.   Excelsior  Blanket
          B.   Plastic Netting
          C.   Jute Mesh
          D.   Paper Fabric
$/hectare
  Total

 $3,404
 $1,293
 $5,294
 $5,814
In all of the above cases,  shipping costs do not exceed 5 percent of the
retail cost of the materials.

The cost estimates of labor required for installation of nets and mulch
blankets varies widely depending on the source.  One manufacturer of
                               228

-------
jute mesh claims that,  with proper installation procedures, jute may be
installed at rates as low as  15 person-days per hectare. On the other
hand, a recent EPA publication (3) indicates installation rates may run
as high as 103 person-days per hectare for steep slopes.  The steepness
and length of slopes does affect, to a moderate degree, the amount of
labor required to install these types of materials.  Data gathered at the
Rubicon Properties erosion project site demonstrates this.  The severely
eroding road cut slopes at Rubicon, where nets and blankets were used,
have slope angles ranging from 31 degrees (1.66:1) to 45 degrees (1:1)
and slope lengths ranging from 4.6 meters to 14.3 meters.  For this
range of slope difficulties,  the term "degree of difficulty" is used to
empirically describe the slope conditions, which is simply the slope
length multiplied by the tangent of the slope angle.  The "degree of
difficulty" is simply a method of correlating the increased manpower
commitments required for the  installation of nets and mulch blankets as
the length and steepness of the slope increases.  Figure VIII-44 depicts
the person-hours of installation time for the four types of nets or mulch
blankets used as part of the  erosion control demonstration project.

Jute netting and paper  fabrics appear to have similar manpower require-
ments.  Jute weighs considerably more than paper fabic.  Thus, jute
requires more effort to spread.  Once positioned on the slope, however,
jute has less of a tendency to be disturbed by wind and is easier to
work with and move around on.  From experience gained at the project
site, Excelsior  blankets require approximately 40 percent more instal-
lation time than either jute  or paper fabric.  The smaller width of the
excelsior roll necessitates approximately 15 to 20 percent more trips
up and down a slope to  place  the material.  Two advantages of the
excelsior are, (1) as claimed by the manufacturer, the material at the
top and bottom of the slope does not need to be buried, and (2) excelsior
blankets may be formed  around slope irregularities such as rocks or clumps.
Plastic netting, over straw,  appears to require about 40 percent less
installation time than  does jute or paper fabric on steep slopes.  This
is due primarily to the extremely light weight of the material and the
larger width (4.6 meters^of  the plastic netting rolls.  Both the plastic
netting and the Excelsior  blanket are almost impossible to use on very
steep slopes.  As a result, these two materials were not used on slopes
with a steepness greater than 1%:1.

For a 10-meter slope with a steepness of 1%:1, the labor requirements
and cost comparisons are derived from Figure VIII-44 and depicted in
Table VIII-13.

                       9.  Fiberglass Roving

Fiberglass roving is actually a type of mulch blanket.  It was not used
at either the Northstar or Rubicon Properties erosion control project
sites, and is thus treated separately.  Fiberglass roving was not used at
the project sites for the following reasons:
                                229

-------
TABLE VIII-13
EQUIVALENT EQUIPMENT AND

Excelsior
Plastic Netting
Jute
Paper Fabric
FOR INSTALLATION

PERSON-
DAYS PER
HECTARE
$130.5
60.0
93.5
95.5
*Note: Does not include seed,


LABOR COSTS

OF MULCH NETS ' AND BLANKETS

MATERIALS
$3,404
1,293
5,294
5,814
fertilizer
DOLLARS/HECTARE
EQUIPMENT LABOR
$804 $16,965
370 7,800
576 12,155
588 12,415
or other mulch costs.

TOTAL*
$21,173
9,463
17,449
18,229

     -    aesthetic and environmental concerns regarding its use
     —    the close proximity of an extensive experimental
          fiberglass roving installation near the Rubicon
          Properties erosion control project site (El Dorado
          County milepost 22.8 on State Highway 89)

Fiberglass roving is formed from molten glass.  It is manufactured-for a
variety of products that utilize fiberglass and commonly is produced in a
coiled package.  The roving is fed through a special nozzle connected to
an air compressor.  The compressed air propels and separates the strands
of glass fibers, spreading them evenly over the ground surface.  A tack
coat of asphalt Cor other tackifier)  is applied over the roving to bind
the strands together and to insure adhesion to the soil (61).  At the
experimental fiberglass roving site near Rubicon Properties, the area was
seeded with grasses and native shrub seeds and fertilized prior to the
roving application.  The application of fiberglass roving is pictured in
Figure VIII—45.  Fiberglass roving has also been effectively used by
CalTrans to control erosion in drainage ditches and swales.

Fiberglass roving has the disadvantage of being nonbiodegradable and,
if associated revegetative measures do not succeed, will leave an
unsightly slope covering.  Considerable objections have been raised
regarding the use of synthetic or nonbiodegradable materials for
erosion control within the Lake Tahoe Basin.  This is particularly true
for materials such as fiberglass roving with its obviously unnatural
appearance.
                                230

-------
    Figure YIII-^45.   Application of fiberglass roving with a
                       compressed air gun.
          HYPOTHETICAL ONE HECTARE ROAD CUT
                                      PAVED  ROAD SURFACE
                                NOTE= NOT DRAWN TO SCALE.
Figure VIII-r46.  Hypothetical one hectare steep,  eroding, cut slope
                   adjacent to a road surface.
                               231

-------
     Roving Costs.   CalTrans recommends that fiberglass roving be applied
     to a site within 24 hours after normal seeding operations have been
     conducted.  The fiberglass roving itself should be applied uniformly to
     form a random mat of  continuous glass fiber at a rate of 0.15 to 0.20
     kilogram per square meter.  Asphaltic material applied over the roving
     should be applied at  a rate of 1.10 to 1.60 liters per square meter.  It
     is recommended that the upgrade end of the roving be buried in a shallow
     ditch above the crown of the slope.  Total treatment cost for fiberglass
     roving, including seed and fertilizer, was estimated by CalTrans to be
     about $6,000 per hectare in 1974.  Estimated installed cost for fiber-
     glass roving as of July 1976 is $8,000 per hectare.

G.   Comparative Erosion Control Costs

     The preceding pages of this section have described in detail a wide
     variety of erosion control measures.  Where possible, an individual
     breakdown of unit materials, equipment, and labor costs is provided
     with each method.   The reader should refer to individual methods and
     to the assumptions listed at the beginning of this section to determine
     how individual cost estimates were developed.  Particular attention in
     the demonstration project has been paid to the most cost-effective meth-
     ods for erosion control on oversteepened slopes in and around the Lake
     Tahoe Basin of California.  A "hypothetical" eroding cut slope is used
     for the purpose of cost comparison.  Such a hypothetical 1.0 hectare
     eroding cut slope is  pictured in Figure VIII-46.  The slope has an aver-
     age slope length of 10 meters and runs for 1,000 meters adjacent to a
     paved roadway.   It is further assumed that the cut has an average slope
     angle of 1.25:1 and is continually sloughing eroded material into a
     poorly constructed drainage structure running along the slope toe.   For
     all practical  purposes, this situation is considered to be typical of the
     erosion problems found throughout the Tahoe-Sierra although actual slope
     dimensions vary considerably from case to case.

     Table VIII-14  summarizes the unit costs and the total costs of selected
     erosion control techniques if they were applied to the hypothetical 1.0
     hectare road cut.   The column entitled "percent labor" refers to.the
     percentage of  the total unit cost which is devoted to labor costs at
     $16.25 per person-hour.  Those percentages which are followed by an
     asterisk indicate those tasks where a majority, if not all, of the labor
     could be performed by unskilled conservation corps workers.

     As can be seen in Table VIII-14, erosion control costs vary considerably.
     Alternative erosion control techniques vary from a single pass with hydro-
     mulching equipment at a cost of $1,800 per hectare to an extensive gabion
     revetment structure costing $227,800 per hectare.  Neither of these
     approaches should be  considered appropriate methods for controlling
     erosion on this type  of slope.  Based upon the various methods demon-
     strated at the Northstar and Rubicon Properties erosion control project
     sites, the best approach would be as follows:
                                     232

-------
                           Hypothetical Scenario

     1.    Construct a curb, gutter and bench system
          at the toe of  the eroding slope
     2.    Manual scaling and overhang removal
     3.    Debris cleanup and removal
     4.    Three rows of  contour willow wattling
     5.    100 kg/ha of seed materials covered with
          4,500 kg/ha straw mulch and chemical
          tackifier treatment

                                       TOTAL
$15,620/1000 meters

  9,644/ha
  4,086/ha
 18,420/3000 meters
  2,200/ha
$49,970/ha
     It is important  to note that all labor costs for the above methods are
     assumed to  be $16.25 per person-hour.  Total erosion control costs may be
     reduced significantly if conservation corps workers are used on portions
     of the tasks  requiring unskilled laborers.  For example, if conservation
     corps workers costing approximately $5.00 per person—hour were used where
     possible to perform nonskill oriented tasks the total cost of the above
     erosion control  scenario would be reduced from $49,920 per hectare to
     $30,387 per hectare.  This represents almost a 40 percent cost reduction.
     Nevertheless, even if conservation corps workers are used to the fullest
     extent, almost 25 percent of the labor required must still be performed
     by skilled  or semi-skilled laborers using heavy or specialized equipment.

     Certain situations will arise when application of the above scenario may
     be difficult. The construction of a curb, gutter, and substantial bench
     system at the toe of the slope requires commitment of a portion of the
     road right-of-way for this purpose.  In some instances, this may require
     reduction of  the required paved road surface or shoulder to less width
     than is required by state law or county ordinance.  If this is the case,
     then either,  1)  exceptions must be made to allow for the construction of
     a curb, gutter,  and bench system, or 2) other alternative stabilization
     techniques  must  be employed.  If a rock or gabion breast wall were con-
     structed in place of a curb, gutter, and bench system at the edge of the
     existing road shoulder, the total cost for implementation of the above
     scenario would be almost doubled from $49,970 per hectare to over $93,000
     per hectare.   Because of the considerable added expense the construction
     of major breast  wall structures should be avoided wherever possible.

     Other substitutions may be made in the above scenario depending upon
     the resources available to perform the required tasks.  However, no
     alternative scenarios are likely to be as cost-effective as the one
     listed above  for severe, steeply eroding slopes.  All of the selected
     erosion control  methods listed in Table VIII-14 will be effective in
     controlling erosion if used in the proper situations.

H.   Preliminary Evaluation of'Erosion Control Effectiveness

     This erosion  control project has resulted in the construction and imple-
     mentation of  various erosion control demonstration plots at Northstar-
     At-Tahoe and  Rubicon Properties.  These .demonstrations were conducted at
                                     233

-------
TABLE Till- 14
COMPARATIVE EQUIVALENT UNIT 'COSTS FOR
' SELECTED 'EROSION 'CONTROL METHODS
USED ON OVERSTEEPENED ' SLOPES


MECHANICAL 'STABILIZATION UNIT COST % 'LABOR
Curbs and Dikes $ 15.62/m 50
1.00m Rock Breast Wall 61.16/m 45
0.90m GaBion Breast Wall* 58.61/m 52*
2.70m GaBion Retaining Fall* 190.48/m 52*
Manual Slope Scaling* 42.68/m;: 96*
Cleanup & DeBris Removal* 0.41/m 96*
Contour Wattling* 6.14/m 82*
GaBion Revetments* 27.78/ni2 40*
Concrete Anti-erosion Grids 24.67/m 48
Gunite Revetments 10.76/m 27
REVEGETATION
Willow Staking* $ 0.60/stake 95*
Rooted ShruB Cuttings* 1.36/plant 60*
Bare Root Seedlings* . 63/plant 86*
Seed w/2800 kg/ha Hydromulch .IS/nu 30
Seed w/5600 kg/ha Hydromulch . 27/m^ 30
Seed w/4500 kg/ha Tacked Straw . 22/nu 30
Seed w/Jute* 1.84/m^ 70*
Seed w/Paper FaBric* 1.92/nu 68*
Seed w/Excelsior* 2.16/m 79*
Seed w/Straw & Plastic Net* 1.07/m. 73*
Seed w/FiBerglass Roving . 80/m N/A
* Those tasks where a large portion of the work may
unskilled conservation corps laBorers.




COST PER
HYPOTHETICAL
HECTARE
$ 15,620
61,160
58,610
190,480
9,644
4,086
18,420
277,800
246,700
107,600

$ 24,000
54,400
26,080
1,800
2., 700
2,200
18,400
19,200
21,600
10,700
8,000
Be performed By

Northstar and RuBicon Properties  from the summer of 1976 through the
spring of 1977.  Prior to 1975, the Soil Conservation Service (SCS) also
established a number of shruB  and herBaceous planting demonstration plots
at Northstar in the spring of  1973  and the spring of 1974.  In all cases,
the demonstration plots were intended to identify and demonstrate the
effectiveness of techniques which could Be used to control the various
types of slope staBilization and  erosion proBlems which were found at
the project sites.  In the case of  Northstar, only a few scattered ero-
sion proBlems could Be identified.   The RuBicon Properties project site,

                               234

-------
on the other hand, required extensive erosion control and slope stabili-
zation corrective measures on over 13 percent of  the subdivision's land
surface.  Complete descriptions of the plots and  the various combinations
of demonstrated techniques which were conducted as part of this project
and as part of the previous work by the SCS  are given in Appendix B of
this report.

The plots at Northstar and Rubicon Properties demonstrate the wide range
of technologies available to stabilize and revegetate severely eroding
slopes.  It is estimated that these various  types of "source control"
techniques will be effective in reducing previous erosion and sediment
yield rates by 80 to 90 percent.  Any erosion control technology can be
deemed successful, however, only if it withstands the test of time.
Time has not yet enveloped this demonstration project, so only prelimi-
nary observations and comparisons can be made.

Toe Stabilization.  Rock walls and gabion baskets seem equally effective
when properly positioned and constructed.  The large rocks in walls have
channeled water to low spots between rocks and caused some erosion at
those points.  The gabion baskets have received multiple wounds from
snow plows.  They are particularly vulnerable to  this type of damage,
and ideally should be thoroughly snow staked.  Repair of damage has
proven difficult because of rolled asphalt gutters  at the base of
baskets.  Gabions are also considered very ugly by most people.  They
gradually fill with dirt, however, so plant growth  in them should be
possible in the future.  Willows placed through the gabions  into the
backfill during construction at Rubicon Properties  are doing well, as
are willow bundles placed behind gabions prior to completion of
Backfilling.

Gutters and dikes are effective when rebuilt to form a bench at the toe
of a steeply eroding slope, and frequently cost less than 25 percent of
•gabion or rock wall construction costs.  Gutters  and dikes also have
fallen prey to snow plows and other types of heavy  equipment and can
only remain effective if protected by snow stakes and  careful maintenance.

Willow Wattling.  The pattern of growth and survival of willow wattling
at Rubicon Properties points to the benefits of gathering and placing
willow wattling when the plants are dormant or semi-dormant. Willows
gathered in July, August and early September did not survive despite
 careful handling  and regular irrigation.  Willows gathered and placed  in
 late September, May, and early June, while dormant or semi-dormant,
have produced a profusion of shoots.  Even though long term survival is
 still a matter of conjecture, correctly installed willow wattling  pro-
vides a  tremendous degree of mechanical soil stabilization even  if the
willow branches eventually die.  Willow wattling considerably  improves
 the opportunity for other  types of plants to take root and grow.

 Plantings.  The Northstar  shrub plantings resulted in better survival
 than has been the case with other plantings in the Tahoe Basin.   This
 is probably due to the relatively good soil and gentle slopes which
 characterize most of the Northstar Plots.  The top performers  among the
                                 235

-------
 shrubs  include several natives, Chrysothamnus nauseosus,  PUrshia
 tridentata, Artemisia tridentata, Penstemon newberryi, Atriplex canescens,
 and Eriogonum umbellatum and several exotics, Caragana arborescens,
 Penstemon strictus,'Salix gracilis, and Salix purpusea.

 Seeding.  Among the grasses, two wheatgrasses, "Tegmar" and "Luna",
 proved  outstanding.  All herbaceous seeding plots were evaluated in  late
 July 1977.  Grass stands were rated on a relative scale from 1  to 10;
 with one  indicating no seeding and ten indicating the best stand on  the
 site.   Evaluations were judgmental, rather than quantitative.   The over-
 all impression of the various treatments on the Rubicon site was that
 they were very similar.  On the 1-10 scale, the maximum difference
 between treatment means was about 2 points.  If this trend continues,
 then there will be no real differences between treatments, and  the most
 cost effective methods will be those that are least expensive.

 Some small treatment differences have been observed.  The higher seeding
 rate (86  kg/ha) tends to produce a denser initial grass stand than the
 lower seeding rate C41 kg/ha).  The additional seed is relatively inex-
 pensive and therefore, may be justifiable.  The higher wood fiber mulch
 rate C5600 kg/ha) produced a slightly better grass stand on the average
 than the  lower mulch rate (;2800 kg/hal.  The additional mulch cost
 almost  $900 per hectare; thus additional mulch may not be cost  effective.
 Straw mulched plots produced slightly better initial grass stands on the
 average than  the hydromulched plots.

 Mulch remaining after the first winter and spring was also evaluated in
 July 1977.  Results, expressed as percentage of plot still covered with
 mulch,  are as follows;
     wood fiber @ 2800 kg/ha
     wood fiber @ 5600 kg/ha
     straw      @ 4500 kg/ha
53%
82%
5 5% A/
The remaining straw mulch coverage for the different tackifiers was as
follows:
     wood fiber CL100 kg/ha) as tack
     Ecology Control
     Dow XFS 4163-L
     Terratack II
     Terratack II Super Concentrate
70%JB/
50%
70%
50%
40%
Future evaluations will yield more definitive results  and possibly reveal
the best method, or methods.
_A/ Average coverage for all straw tackifier treatments.
B/ Wood fiber coverage includes ground covered by the wood fiber tacki^
   fier as well as ground covered by straw.
                                236

-------
                                 SECTION IX

            INSTITUTIONAL PROCEDURES FOR EFFECTIVE EROSION CONTROL
Sufficient regulatory control now exists in California to  insure  that problems
similar to Rubicon Properties can never develop  in the future.  The
California State Water Resources Control Board (State Board)  and  the nine
Regional Water Quality Control Boards (Regional  Boards)  have  regulatory
authority over the water resources of the State  (62).   As  empowered  by the
laws of the State of California, one of the regulatory tools  available to the
State and Regional Boards is  the establishment of waste discharge requirements.
In addition to other types of pollutants, waste  has also been defined to
include "waste from construction activities".  This has been  interpreted  in
court to include eroded sediments resulting from improper  construction
methods.  If waste discharge  requirements established for  a particular
discharge are violated, then  several alternatives are available to a Regional
Board to force a discharger into compliance.   Among them are:

          A time schedule for compliance with waste discharge requirements
          may be ordered by a Regional Board,

          A Cease and Desist  Order requiring tb_e discharger to comply with
          waste discharge requirements may be adopted by a Regional  Board,

          A Cleanup and Abatement Order-may be issued to the  discharger re-
          quiring him to cease discharging waste in violation of  waste dis-
          charge requirements and cleanup any waste discharged to the waters
          of the State.

further violation of waste discharge requirements or any of the above orders
may be referred to the Attorney General of the State to collect civil
monitary remedies from the discharger for up to  $10,000 per day,  or  to enjoin
such activities as may be causing violation of waste discharge requirements.

In the case of the operation  of wastewater treatment plants in California,
the State and Regional Boards are not allowed to specify which treatment
processes must be used to meet waste discharge requirements.   However, unlike
wastewater treatment plants,- California Law (Water Code, Section  13360) permits
the State and Regional Boards to describe specific methods which  must be  used
to control eroding (or threatening to erode) waste earthen materials.  Typical
waste discharge requirements  which may be applied by the Regional Board in  the
Lake Tahoe vicinity to current and proposed future construction projects
which pose existing or threatened erosion problems are as  follows:
                                      237

-------
A.   General Waste Discharge  Requirements

     .     The discharge of  treated or untreated domestic sewage, industrial
          waste,  garbage or other solid wastes, or any other deleterious
          material to  surface waters is prohibited.

          The discharge, attributable to human activities, of solid or liquid
          waste materials,  including soil, silt, clay, sand, and other organic
          and earthen  materials, to surface waters is prohibited.

          The discharge, attributable to human activities, of solid or liquid
          waste materials,  including soil, silt, clay, sand, and other organic
          and earthen  materials, to lands within the highwater rim (Elevation
          6229.1  ft. MSL) of  Lake Tahoe or within the 100-year flood plain of
          any tributary to  Lake Tahoe is prohibited.

     .     The discharge shall not cause a pollution.

          Neither the  treatment nor the discharge of waste shall cause a
          nuisance.

          The discharge shall not cause any measurable color, odor, bottom
          deposits, floatable materials,, oil, grease, or radionuclides to be
          present in any surface waters,

B.   Specific Waste Discharge'Requirements

                         1.  Construction Drainage

          The transport of  suspended sediment by drainage or surface flows
          from disturbed areas under construction to adjacent land areas or
          surface waters is prohibited.

          Adequate erosion  control and sediment or surface flow containment
          facilities shall  be constructed and maintained to prevent discharge
          of waste earthen  material from disturbed areas under construction.

          There shall  be no significant modification of existing drainage
          ways or existing  stream channel geometry which would allow a     '
          discharge of sediments or eroded materials to adjacent properties
          in violation of other provisions of these requirements.

          Earthen berms or  other sedimentation barriers shall be located
          downgradient from construction areas to prevent the discharge of
          earthen waste onto  adjacent land areas or surface waters.

          Rock slope protection aprons shall be placed at the outlet of all
          culverts to  prevent scour.
                                      238

-------
All disturbed street surfaces shall be periodically  sprinkled
lightly and swept by a mechanical sweeper  as necessary to prevent
fine material from being discharged into drainage ways.

The length of the open trench at the end of each working day shall
not exceed 50 feet.

Any damage or break in existing water lines shall be immediately
repaired and measures must be immediately  implemented to prevent
erosion or sedimentation into any drainage way.

Water discharged from any sewage or water  facilities including water
from testing lines shall be disposed of in such a manner as to not
cause erosion or sedimentation or discharge of waste earthen
materials into any drainage way.

                  2.  Construction Waste

The discharge of surplus or waste material including, but not
limited to, soil, sand, silt, clay, or other earthen materials, to
drainage ways is prohibited.

The placement of waste earthen materials in such a manner as to
allow the discharge of any portion of such materials to adjacent
drainage ways is prohibited.

There shall be no surplus or waste material, including soil, sand,
silt, clay, or other earthen materials, placed in drainage ways.

All loose piles of soil, silt, sand, clay, debris, and other earthen
materials shall be protected in a reasonable manner  to eliminate
discharge to waters of the State.

All surplus soil, silt, sand, clay, or other earthen materials shall
be removed from the site after construction and deposited in a loca-
tion so as to eliminate the sedimentation  of surface waters.

All rock riprap used for slope protection  shall be cleaned of soil
and carefully placed so as not to cause sedimentation or increased
turbidity in surface waters.

Materials used in dams, dikes, and levees  used in creek crossings
shall consist of sandbags filled with clean sand or  other nonsilting
materials.

At all creek crossings, and whenever the natural bank of the river
is disturbed, or where called for on the construction plans, rock
riprap slopes protection shall be provided for erosion protection
during high flows.
                            239

-------
Fresh concrete and cement shall not be allowed  to  enter  surface
waters.

                     3.  Storm Runoff

Effluent discharged from a grease trap/sedimentation basin shall
not appear as surface flow, but must be infiltrated by a subsurface
percolation bed, except for a greater than 1 hour  20-year storm.

A maintenance program shall be established to ensure proper opera-
tion of the grease trap/sedimentation basin and subsurface
percolation bed.

Waste removed from the grease trap/sedimentation basin shall be
disposed of in an approved manner.

Drainage collection, retention, and infiltration facilities shall be
constructed and maintained to prevent transportation of  waste from
areas of completed construction.

Surface flows from the subject property shall be controlled so as
to not cause downstream erosion at any point.

Storm runoff from paved areas shall be diverted to percolation
facilities on the project site.

The infiltration trench system shall be installed  around the
perimeter of the site and shall be so designed  such that any runoff
in excess of the trench storage and percolation capacity is
discharged to a storm drain.

An oil and grease trap shall he installed in the storm drainage
system immediately prior to discharge to the storm drain.

Sheet flow of runoff shall be retained to prevent  drainage
concentrations.

Suitably designed, gravel filled infiltration trenches are to be
located under roof drip lines.

Trenches at the edge of driveway and parking areas shall be cleaned
periodically to remove grease and gasoline residues that may
accumulate.

Energy dissipators shall be provided where erosive velocities will
occur.

Cross ditches shall be installed and maintained on slopes where
vegetation does not provide adequate soil stabilization.
                            240

-------
                    4.   Disturbed Areas

There shall be no disturbance of natural vegetation  or  soil
conditions except where erosion control  measures  can be installed
and operational prior to October 15 of each year.

There shall be no disturbance of natural vegetation  or  soil condi-
tions between October 15 and May 1 of each year.

Cut and fill slopes which may result from construction  on  the
subject property shall be designed with  slopes not exceeding two
horizontal to one vertical.

All nonconstruction areas shall be protected by barriers or fencing
to prevent disturbance.

Stream alteration areas and stream relocation areas  shall  be
stabilized by the addition of rock slope protection  as  necessary,
periods of no flow.

Ephemeral stream relocation areas shall  be flared at each  downstream
end to conform to existing stream patterns.

                     5.  Revegetation

Disturbed areas shall be adequately restabilized  and the
stabilization facilities shall be continually maintained.

All cut and fill slopes, except predominantly rocky  areas, shall be
reseeded and/or revegetated with plants  indigenous to the  area.  A
cut and fill slope management program shall be implemented to ensure
that all reseeded areas develop root systems sufficient to prevent
erosion.

                 6.  Effluent Limitations

The discharge from the subject site shall not contain any  percep-
tible floating material including, but not limited to solids,
liquids, foams, and scums.

The discharge from the subject site shall not contain oils, greases,
waxes, or other hydrocarbon or petroleum derivative  materials that
cause visible film or coating on the surface of the  receiving water
or on objects in the receiving water.

The discharge from the subject site shall not contain settleable
substances in concentrations that may result in the  deposition of
material in any surface waters.
                            241

-------
The discharge from the subject site shall not have a pH value below
7.0 units nor greater than 8.4 units.

The discharge from the subject site shall not contain substances  in
concentrations individually, collectively, or cumulatively toxic,
harmful, or deleterious to humans, animals, birds, or aquatic
biota, including, but not limited to, those substances specified  in
the California State Drinking Water Standards.

All surface flows generated from the project site which are dis-
charged to surface waters or storm drainage systems shall not
contain constituents in excess of the following limits:
Constituent              Units

Total Nitrogen           mg/l-N
(Nitrate & Kjeldahl)

Total Phosphate          mg/l-P

Turbidity                FTU

Suspended Sediment       ™S/1

Phenolic Compounds       mg/1

C.O.D.                   mg/1

MBAS                     mg/1

Apparent Color           c.u.
Meanl/

 0.25


 0.02

 3.0

25
Maximum

   1.5


   0.1

  20

  80

   0.04

  10

   0.15

   5
—   Arithmetic mean value of any ten (10)  consecutive samples.
If the water quality constituent levels of waters  entering or
passing adjacent to the subject property or any work area or waste
producing facility within the subject property from upstream areas
are' of a superior or equal water quality to the numerical standards
above, those waters shall meet the water quality constituent levels
listed above prior to discharge from the property.

Lf the water quality constituent levels entering the subject
property or any work area or waste producing facility within the
subject property exceed the numerical standards specified above,
there shall be no more than a ten percent increase in the down-
stream value as compared to the upstream value.
                            242

-------
                               7.  Provisions

          The  discharger shall comply with the Monitoring and Reporting
          Program and requirements established by the Regional Board.

          The  discharger shall immediately notify the Regional Board by tele-
          phone whenever an adverse condition occurs as a result of this
          discharge; written confirmation shall follow.

          Any  proposed material change in the character of the waste, method
          of disposal, increase of discharge, or location of discharge shall
          be reported to this Regional Board.  This shall include all
          signifficant soil disturbances and stream channel modifications.

          The  Regional Board reserves the privilege of changing all or any
          portion of the waste discharge requirements upon legal notice
          and  after opportunity to be heard is given to all concerned parties.

          The  owner of the property subject to waste discharge requirements
          shall be considered to have a continuing responsibility for ensuring
          compliance with applicable waste discharge requirements in the
          operation or use of the owned property.  Any change in the ownership
          and/or  operation of the property subject to waste discharge require-
          ments shall be reported to the Regional Board.  Notification of
          applicable waste discharge requirements shall be furnished the new
          owner(s) and/or operator(s).  A copy of such notification shall be
          sent to the Regional Board.

          Surface waters, as used in this Order, include, but are not limited
          to,  live streams, either perennial or ephemeral, which flow in
          natural or artificial water courses and natural lakes and
          artificial impoundments of waters within the State.

C.   A Case History

The enforcement of the above waste discharge requirements for ongoing or
future construction activities is relatively straightforward.  An entity or
person found to be in violation of waste discharge requirements may be
enjoined, be forced to pay stiff monitary remedies, and/or receive a jail
sentence.  In  the Lake Tahoe vicinity, the Regional Board is actively engaged
in applying waste discharge requirements of the type listed above to new
construction projects.  Coupled with vigorous enforcement, waste discharge
requirements have altered construction activities so that they produce even
less severe erosion and sediment related pollution problems than the low
levels found at Northstar (less than a one fold increase above natural
background levels).  Certainly, there will never be future developments which
have such severe  erosion and sediment control problem as are found within the
Rubicon Properties Subdivision.
                                      243

-------
With present and future construction related erosion  and  sediment problem well
under control, the remaining problem is to control  erosion and sediment pollu-
tion generated by past construction activities.   Erosion  control at Rubicon
Properties is an excellent example of the types  of  problems which are
encountered in controlling erosion in past developments.  The original
developer of Rubicon Properties has long since sold all interest in the
development.  Most likely he cannot be held accountable for the poor planning,
construction, and development practices exhibited there.  The only potentially
responsible parties are the several hundred hapless individual landowners
within the development and the County.   The following chronology of events
is a brief description of the attempts  that were made t:o  control erosion
problems within Rubicon Properties.

In 1970, the California Regional Water Quality Control Board, Lahontan Region
(Lahontan Regional Board) established waste discharge requirements on the
County and over 200 privately owned parcels within«Rubicon Properties
Subdivision, Unit No. 2 (upper portion) (63).  This was the initial formal
attempt to coerce the County and the landowners  into  correcting the massive
erosion problems that existed there.   Replies  were  received from over 50
percent of the landowners, all of which stated,  to  the effect, that their
individual holdings were not contributing to the erosion  problems.  Further-
more, the landowners requested that they no longer  be described as
"dischargers".  Without lengthy court proceedings,  it would have been
difficult cult to prove that they were dischargers  and were responsible for
the erosion problems.  The County, although remiss  in accepting the
Subdivision in the first place, was unable to  proceed because of a lack of
funds and knowledge concerning effective erosion control.

By 1971, the Lahontan Regional Board adopted an  interim basin water quality
control plan which formally established the following beneficial uses for the
waters of the Lake Tahoe Basin (64):

          Domestic supply
          Agricultural supply
     .    Water contact recreation
          Nonwater contact recreation
          Scientific study
          Fresh water habitat
          Fish spawning

To protect the beneficial uses, the interim basin furthermore established
several waste discharge prohibitions, including:

     .    The discharge of solid or liquid materials, including soil, silt,
          clay, sand, and other organic and earthen materials, to Lake Tahoe
          or any tributary thereto.

          The discharge of solid or liquid waste materials, including soil,
          silt, clay, sand, and other organic and earthen materials, to lands
                                      244

-------
          below the hlghwater rim of Lake Tahoe or within the 100-year
          flood plain of any tributary to Lake Tahoe.

          The threatened discharge of solid or liquid  waste materials,  includ-
          ing soil, silt, clay, sand, and other organic and earthen materials,
          due to the placement of said materials below the highwater  rim of
          Lake Tahoe or within the 100-year flood plain of any tributary to
          Lake Tahoe.

In 1972, the Lahontan Regional Board proceeded with  an intensive water
quality investigation within Rubicon Properties.  The  purposes of  this
investigation were twofold (1) to determine the overall extent of  the erosion
problem, and (2) to determine the principle sources  of eroded sediment  within
the Subdivision.  The investigation determined that  the roadway cuts  and fills
adjacent to. county maintained roadways and extending onto many private
parcels, were primarily responsible for the massive  sediment load  of  Lonely
Gulch Creek.  Although unable to quantify the annual sediment load at that
time, the Lahontan Regional Board substantiated the  large reduction in  insect
species populations and diversity within the Creek,  It was concluded that
erosion from-the development was the principle reason  for the observed
reductions in aquatic life.

In 1973, the County retained the services of a consultant to determine  what
procedures should be employed at Rubicon Properties  to correct the erosion
problems (65).   In addition,  all major erosion problems were identified within
the Lake Tahoe Basin portion of the County and ranked  as to degree of severity.
Rubicon Properties, Unit No.  2, was ranked as the number one priority problem.
The total cost of erosion control of all problems within the County was iden-
tified to be $1.5 million.   The cost to solve the problems within  Rubicon
Properties,  Unit No. 2, was estimated at $218,089.

In 1974, The Lahontan Regional Board issued a second set of waste  discharge
requirements naming the County as the sole responsible party for the
correction of the erosion problems within Rubicon Properties (66).  October 1,
1975, was identified as the date by which all required erosion control  work
must be completed.   However,  arguments were put forward by the County that
insufficient funds existed to correct the problems at  Rubicon Properties.  Even
though specific erosion control recommendations were made by the consultant,
the County also felt that insufficient knowledge existed to guarantee
success if the proposed control measures were implemented.'  As a result, no
enforcement actions were taken by the Lahontan Regional Board and  matters
appeared to have reached a state of impasse.   Injunctions  against  the results
of past construction activities are meaningless and  civil monetary suits
against public entities, such as the County,  are difficult to obtain  and
frequently accomplish very little.

In 1975, the Lahontan Regional Board adopted a plan  which updated  and
replaced the interim basin plan (67).   Additional water quality objectives
were "established for Lake Tahoe,  including specific  objectives for Lonely
                                      245

-------
Gulch Creek.  Also in 1975, the upper portion of Rubicon Properties within
the Lonely Gulch Creek watershed was identified as an erosion and sediment
control site as part of this erosion control project by the State Board.
Until this time, very little had been done to control erosion at Rubicon
Properties beyond normal maintenance activities.  However,  because
additional funds were available to supplement their resources,  the County
readily agreed to assist the State Board in demonstrating a variety of
erosion control techniques.  Prior to 1975, the County had invested approxi-
mately $11,500 per year at Rubicon Properties,  primarily for cleanup and
maintenance activities.  However,, once additional funds were assured from
outside sources, the County expended the equivalent of $65,000  in county
manpower and equipment to-assist the State Board in correcting  erosion
problems at Rubicon Properties.  This was spent during the 15-month period  from
July 1975 through September 1976.  The erosion control measures which were
implemented at the Rubicon Properties as a result of this erosion control
project are fully described in Section VI and Appendices A and  B.


                                   Summary

Ample controls exist to insure that current and future construction
activities will provide sufficient erosion control.   The control of erosion
from past activities,  although ample regulatory control exists, requires a
substantial capital investment.  For the most part,  these capital investments
must be made by public agencies,  as exemplified by the situation at Rubicon
Properties.  The erosion control project has demonstrated that  effective
erosion control does not have to be exorbitantly expensive and,  if pre-
control maintenance costs are high, may be amortized in a relatively short
period of time (12.5 years or less in the case of the Rubicon Properties
project site) through local maintenance cost savings.   However, the rapidity
at which erosion control problems generated in the past may be  corrected can
only be rapidly accelerated if the resources of the directly responsible
local entity are supplimented by assistance from other interested public or
private contributors.   The assistance could easily take the form of labor,
equipment, materials,  or monitary contributions.  As exemplified by the
chronology of events surrounding erosion control at Rubicon Properties,
without a certain degree of outside assistance, remedial erosion control of
past mistakes in rapidly developed areas, such as Lake Tahoe, will be an
extremely time-consuming if not impossible process.
                                      246

-------
                                  SECTION X

                                  REFERENCES
 1.    "Sedimentation and Erosion  in the Upper Truckee and Truckee and Trout
      Creek Watershed, Lake Tahoe, California."  Resources Agency, State of
      California, July 1969.

 2.    Goldman,  Charles R., "Eutrophication of Lake Tahoe Emphasising Water
      Quality," U.  S. Environmental Protection Agency, EPA-660/3-74-034,
      December  1974.

 3.    Baker,  John A., "Siltation  Evaluation Investigation for the Lake Tahoe
      Basin," California Regional Water Quality  Control Board, Lahontan
      Region, June  1976.

 4.    Debacker, George H., et  al, "A  Presentation of North Star," Tahoe City,
      California, May 21,  1971.

 5.    "Development  Plan Review,"  Eckbo, Dean, Austin & Williams, inc., San
      Francisco, June, 1970.

 6.    "Logging  Road and Protection of Water Quality," Environmental Protection
      Agency, PB-243703, March, 1975.

 7.    "Sediment Yield and  Land Treatment," U. S. Department of Agriculture,
      September, 1972.

 8.    "An Investigation of Soil Characteristics  and Erosion Rates on California
      Forest  Lands."  Resources Agency, State of California, October, 1976.

 9.    "A Method for Regulating Timber Harvest and Road Construction Activity
      for Water Quality Protection in Northern California."  Water Resources

10.    Dames and Moore, Thirteen Soils Report for Various Northstar Units,
      between March 1971 and March 1972.

11.    Eckbo,  Dean,  Austin  & Williams, Nine Environmental Impact  Reports for
      Various Northstar Units, 1971 and 1972.

12.    "Northstar-At-Tahoe  Planting and Revegetation Management Program," Eckbo,
      Dean, Austin  & Williams, San Francisco, August 1971.
                                      247

-------
13.  Zinke,  Paul J.,  "Ecologic Review—Northstar-At-Tahoe,"  1971.

14.  Personal communication with Dick Englehardt, Vice-president, Northstar-
     At-Tahoe, June 1977.

15.  "Soil Survey:   Tahoe Basin Area, California and  Nevada,"  U.S.D.A.,
     Washington, B.C.,  March,  1974.

16.  Bailey, Robert G., "Land-Capability Classification of the Lake Tahoe
     Basin,  California-Nevada, a Guide to Planning,"  U.S.D.A.,  1974.

17.  "Ordinance No. 357:  An Ordinance to Amend the El Dorado  County
     Subdivision Ordinance (No. 139)  by Adding Provisions Relating to Water
     Supply and Distribution Systems, and Specifications for Road Construction,
     "El Dorado County, March 30, 1959.

18.  "Policy for the Administration of Water Rights in the Lake Tahoe Basin,"
     California State Water Resources Control Board,  July 15,  1976.

19.  "Notice to Water Users in the Lake Tahoe and Truckee River Basins,"
     California State Water Resources Control Board,  July 15,  1976.

20.  Burgy,  Robert H. and Allen W. Knight, "The Tahoe Basin  Siltation
     Monitoring Program, Interim Report," State Water Resources Control Board,
     the Resources Agency, State of California,  Sacramento,  California, 1973.

21.  Guy, H. P., "Laboratory Theory and Methods for Sediment Analysis"; U. S.
     Geological Survey  Techniques Water-Resources Inv., Book 5, Chap. Cl,
     p. 58,  1969.

22.  "Standard Methods  for the Examination of Water and Wastewater," 13th
     Edition, American  Public Health Association, New York,  1970.

23.  Needam, Paul R.  and Robert L. Usinger, "Variability in  the Macrofauna of
     a Single Riffle in Prosser Creek, California, as Indicated by the Surber
     Sampler," Hilgardia,  Vol. 24, No. 14, pp. 383-409, 1956.

24.  Allen,  K. R.,  "The Distribution of Stream Bottom Fauna."  Proc. N. Z. Ecol.
     Soc. 6, 5-8, 1959.

25.  Davis,  William E., "The Effects of Physical Degradation on the Benthos
     of a Northern California Stream," Masters Thesis Humboldt State College,
     Arcata, California, 1966.

26.  Cairns, J., Jr.  and K. L. Dickson, "A Simple Method for the Biological
     Assessment of the  Effects of Water Discharges on Aquatic  Botton-Dwelling
     Organisms."  Journal of the Water Pollution Control Federation,, 43(5):
     755-772, 1971.

27.  Usinger, Robert L., Editor. Aquatic Insects of California. University
     of California Press,  Berkeley, 1971.
                                      248

-------
28.   Ward,  Henry B.  and George Whipple,  Fresh-Water  Biology. John Wiley and
     Sons,  Inc., New York,  1959.

29.   Pennak,  Robert  W., Fresh-Water Invertebrates of the United  States, Ronald
     Press  Company,  New York,  1953.

30.   Allen, J.  T. and A. W. Knight, "The Use of Benthic Assemblages  to Assess
     Stream Perturbation Effects:   Data Analysis Methods."  Tahoe Basin
     Siltation Evaluation Program, State Water Resources Control Board,
     Sacramento, California, 1974.

31.   Egloff,  D. A. and W. H. Brake!, "Stream Pollution and a Simplified
     Diversity Index."  Journal of the Water Pollution Control Federation,
     46 (11):  2269-2275, 1973.

32.   Sokal, Robert F. and F. James Rohlf, Biometry,  W. H. Freeman and Co.,
     San Francisco,  1969.

33.   Hutcheson, K. "A Test for Comparing Diversities Based on the Shannon
     Formula." Journal of Theoretical Biology, 29:  151-154, 1970.

34.   "Whittaker, R.  H., "Gradient Analysis of Vegetation," Biological Reviews
     42:207-264, 1967.

35.   "Snow Survey Sampling Guide," U. S. Soil Conservation Service  Agr.
     Handbook 169, December 1953.

36.   Tebo, L. B., Jr.,"Effects of Siltation, Resulting from Improper Logging,
     on the Bottom Fauna of a Small Trout Stream in the Southern Appalachians."
     Prog. Fish-Cult., Vol. 17, No. 2, pp. 64-70, 1955.

37.   Cordone, A. J. and D. W. Kelley, "The Influences of Inorganic  Sediment
     on the Aquatic Life of Streams."  California Fish and Game, 47(2):
     189-228, 1961.

38.  Marlier, G., "Recherches Hydrobiologiques dans les Rivieres du Congo
     Oriental II.  Etude Ecologique."  Hydrobiologia, 6, 225-64, 1954.

39.  Hornuff, L. E., "A Survey of Four Oklahoma Streams with Reference to
     Production."  Rep. Okla. Fish. Res. Lab. 62, 1-22, 1957.

40.  Fitthau, E. J. "Remarks on Limnology of  Central-Amazon Rain Forest
     Streams."  Verh. int.  Verein.  theor. angew. Limmol. 15, 1092-6, 1964.

41.  U. S. Environmental Protection Agency, Office of Water Programs
     Operations,  Comparative Costs  of Erosion and Sediment Control Construction
     Activities, July  1973.

42.  U. S. Environmental Protection Agency, Office of Research and Monitoring,
     Guidelines for  Erosion and Sediment Control Planning and Implementation,
     August  1972.
                                      249

-------
 43.  U. S. Environmental Protection Agency, Office of Air and Water
     Programs, Processes, Procedures, and Methods to Control Pollution
     Resulting from all Construction Activity, October 1973.

 44.  U. S. Environmental Protection Agency, Office of Water Planning and
     Standards, Methods of Quickly Vegetating Soils of Low Productivity,
     Construction Activities, July 1975.

 45.  State of California, Department of Transportation, Equipment Rental Rates
     and General Prevailing Wages Rates, June 1976

 46.  Leiser, Nussbaum, Kay, Paul, and Thornhill, Revegation of Disturbed Soils
     in the Tahoe Basin, California Department of Transportation, June 1974.

 47.  U. S. Department of Agriculture, U. S. Forest Service, Forest Service
     Manual, Title 2500 - Watershed Management, May 1976.

 48.  Regional Water Quality Control Board, Lahontan Region, Estimation of
     Rainfall Excess by Soil Cover Complex Analysis;  Infilitration Trench
     Design, unpublished staff report by Gerard Thibeault. March 1977.

 49.  U. S. Department of Agriculture, Soil Conservation Service, National
     Engineering Handbook, 1964.

 50.  Hjedmfelt and Cassidy, Hydrology for Engineers and Planners, Iowa
     University Press, Ames, 1975.

 51.  Peurifoy, R. L.,  Estimating Construction Costs,  McGraw - Hill,  New York,
     1975.

 52.  Kraebel,  C. J.,  "Erosion Control on Mountain Roads", U. S.  Department of
     Agriculture Circular No. 380, March 1936.

 53.  U. S. Department of Agriculture, Soil Conservation Service, Plant
     Materials Study - A Search for Drought Tolerant  Plant Materials for
     Erosion Control,  Revegetation, and Landscaping Along California Highways,
     June 1976.

 54.  Kay,  Burgess L.;  "Revegetation of Mountain Sites Above 3,000 ft.  in
     California, Agronomy Progress Report,  No.  53  University of California,
     Davis,  September 1973.

55.  Kay,  Burgess L.;  "Role of Fertilization in Planting of Critical Areas"
     Erosion Control Symposium,  Proceedings USDA - SCS,  U.  C.  Davis,  June
     1974.

56.  Kay,  Burgess L.,' et al,  "Pellet Inoculated Legume Seeds are OK  in
     Hydromulching", Agronomy Progress Report,  No. 44,  University of California,
     Davis,  August 1972.
                                      250

-------
57.  Kay, Burgess L.;  "New Mulch Materials  Tested for  Hydroseeding" Agronomy
     Progress Report,  No.  39;  University of California,  Davis,  July 1972.

58.  Kay, Burgess L.;  "The Role of Erosion Control Fibers  and Chemicals",
     Erosion Control Symposium, Proceedings,  USDA - SCS, U.  C.  Davis,
     June 1974.

59.  Kay, Burgess L.;  "Hydroseeding,  Straw, and Chemicals  for Erosion  Control",
     Agronomy Progress Report, No. 77,  University of California,  Davis,  June
     1976.

60.  Kay, Burgess L.;  "Tackifiers for Straw Mulch", Agronomy Progress  Report,
     No. 76 University of California, Davis, April 1976.

61.  State of California, Department of Transportation,  Fiberglass Roving for
     Erosion Control,  Highway Study Report, June 1974.

62.  "The Porter-Cologne Water Quality Control Act," State of California, 1970.

63.  Order No. 6-70-36, "Waste Discharge Requirements for  Rubicon Properties
     Unit Number 2 Subdivision, El Dorado County," California Regional Water
     Quality Control Board, Lahontan Region, October 1,  1970.

64.  "Water Quality Control Plan  (Interim), North Lahontan, Basin 6A,"
     California Regional Water Quality Control Board,  Lahontan  Region,
     June 1971.

65.  "Erosion Control and Surface Water Management, Lake Tahoe  Portion of El
     Dorado County," J. B. Gilbert and Associates, December 1973.

66.  Order No. 6-74-87, "Waste Discharge Requirements for El Dorado County
     Siltation.and Erosion Correction Priority Areas (Rubicon Properties)
     Lake Tahoe Basin," California Regional Water Quality Control Board,
     Lahontan Region, August 22,  1974.

67.  "Water Quality Control Plan  Report, North Lahontan Basin (6A),"
     California State Water Resources Control Board, Lahontan Region,
     April 1975.
                                      251

-------
                                   APPENDIX  A

                 PLANT PROPAGATION FOR THE REVEGETATION OF  ROAD
                     CUTS AND FILLS IN THE LAKE TAHOE BASIN

                                    CONTENTS
                                                                      Pae
 1.

 2.

 3.

 4.

 5.

 6.

 7.

 8.

 9.

10.
Introduction
Obj actives
Soil Mixes
Containers
Growing Conditions
254
255
256
256
257
Plant Materials - Principal Plants Investigated	   257
Plant Materials - Other Species Investigated

Outplantings	

Summary 	
Costs
267
270
273
276
                                      252

-------
                                 APPENDIX A

                                    TABLES
Number                                                               Page

A-l       Artemisia tridentata.   Survival in 3  soil mixes,  3^
          months after transplanting 	  258

A-2       Atriplex gardneri.   Survival in various  soil mixes and
          container types,  5  months after planting 	  258

A-3       Penstemon newberryi.  Survival in 3 containers  and 3  soil
          mixes, July and August, 1976 	  260

A-4       Rooting of Prunus emarginata root suckers under various
          conditions 	  262

A-5       Response of Prunus  emarginata seeds to hot  and  cold
          water pre-soaking and three stratification  regimes 	  262

A-6.      Response of Prunus emarginata seeds to soaking  times  and
          temperature during stratification, fall  1976  	  264

A-^7       Survival of Prunus  emarginata seedlings  in  3 containers,
          spring 1977	  264

A-8       Purshia tridentata seed response to several pre-germination
          treatments, spring 1976 	  265

A-9       Effect on hormone and cutting diameter on rooting of  Salix
          lemmonii and S. lasiantra	  266

A-10      Salix spp.  Comparison of rooting of  several species  of
          Salix as influenced by cutting diameter  and hormone
          treatment	  268

A-ll      Inventory of plant materials delivered to Rubicon Properties
          Erosion Control Project Site 	  271

A-12      Total Cost of Rooted Cuttings 	  277

A-13      Growing Cost Summary—Unit Costs	  279
                                      253

-------
                                   APPENDIX A
                           Plant Propagation for the
                      Revegetation of Road Cuts and Fills
                            in the Lake Tahoe Basin

                   Department of Environmental Horticulture
                        University of California, Davis
                   Andrew T. Leiser, Principal Investigator

                                      for

                 California 'State Water Resources Control Board
                               1.  Introduction

Highway cuts and fills in the Lake Tahoe Basin often are slow to establish
vegetation cover or do not establish such cover at all.   The soils  and sub-
soils of this area are subject to extreme erosion when devoid of vegetation
because of the course textured soil types, periods of heavy water run-off,
frost heaving and wind action.  This erosion is detrimental to streams and
lakes in the Lake Tahoe Basin, causes costly road maintenance work,  endangers
property and people and is aesthetically objectionable.

A 3% year study for the California Department of Transportation (CalTrans)
completed in 1974 has shown that it is possible to revegetate these difficult
sites with combinations of mechanical stabilization and  revegetation using
native plant species.  The time and financial restraints of this project
were such that only a portion of the potentially useful  native plant spectrum
were tested in adequate quantities and several possible  techniques  of mechani-
cal and vegetative stabilization were either not evaluated or were  evaluated
in a limited way.  Although much was learned about the propagation,  culture
establishment of native plant materials on these difficult sites, the usable
plant spectrum is limited by our present knowledge.   Survival and growth of
those species tested in quantity (e.g. Arctostaphylos nevadensis, pine mat
manzanita; Artemisia tridentata, big basin sagebrush; Ceanothus prostratus,
squaw carpet; Purshia tridentata, Antelope brush;  and Penstemon newberryi,
mountain pride)  might be enhanced by better cultural practices which would,
for example, permit development of better root systems.   A number of species
were evaluated in very limited quantities (e.g.  Symphoricarpos acutus,  creep-
ing snowberry; Lonicera conjugialis,  double-fruited  honeysuckle; Chryso-
thamnus nauseosus, rabbit brush; Arctostaphylos  patula,  green leaf manzanita;
Cercocarpus ledifolius, curl leaf mountain mahogany;  Rhamnus  rubra,  Sierra
coffeeberry; and Spiraea densiflora,  mountain spiraea) because of limited
                                      254

-------
resources, difficulty of propagation and growth, or lack of propagating
material  (i. e. seeds, cuttings).  Many of these show promise of being very
useful if propagation and cultural practices can be solved.  A number of other
species which, in their native habitat, show a wide range of adaptation  to
microenvironment and inherent ability to stabilize bare soils were not evalu-
ated due  to poor seed production during the course of this project or diffi-
culties in propagation or culture.  These include Prunus emarginata,  bitter
berry; Querus vaccinifolia, huckleberry oak; Nama lobbii, woolly nama;
Castanopsis sempervirens, bush chinquapin; Ceanothus cordulatus, mountain
whitehorn; Lupinus spp., lupine; and Rubus parviflorus, thimbleberry. These
should be studied in great detail in order to effectuate a more thorough
representation of the vegetation in the Tahoe Basin.

'Still other potentially valuable revegetation species were not evaluated due
to time and financial restraints of the project or becaus.e sufficient observa-
tions of  their potential were not made in the early portions of this  project.
Some examples are Rosa woodsii var. ultramontana, mountain rose; Symphori-
carpos vaccinoides, mountain snowberry; Lonicera caurina, mountain fly honey-
suckle; Lonicera involucrata; Ribes divaricatum var. inerme; Ribes montigenum,
mountain  gooseberry; Ribes roezlii, Sierra gooseberry; Ribes cereum,  squaw
currant; Ribes viscosissimum, sticky currant; Ribes nevadense, mountain  pink
currant; Ceanothus velutinus, snowbrush; Holodiscus microphyllus, littleleaf
cream bush; Amelanchier pallida, Western service-berry; and Amelanchier
pumila, smooth service-berry.  The Salix spp. (other than Salix lemmonii,
lemon willow) should be investigated.  These should include studies of relative
rootability and performance of several species, if funding permits.  Certain
herbaceous genera would also warrant exploration, such as Eriogonum spp. and
Lupinus spp., Lupines.

Additional research on propagation, culture and establishment of methods for
species of proven revegetation potential, of species evaluated only in limited
trials and on species not included in earlier research would provide  a plant
spectrum  from which to choose the best species for virtually any microsite
in the Lake Tahoe Basin or other similar habitats.
                               2.  Objectives
The objectives were to:
          Survey study sites, evaluate physical and microenvironment conditions
          and select potentially useful species for revegetation.

          Research propagation and cultural practices to produce the required
          plant spectrum.  Specific studies to be made of seed versus cut-
          ting propagation, growing media, depth of containers, irrigation
          and nutritional needs (in. the nursery) and timing of propagation.
          These studies will provide 10-20,000 plants,  depending on level  of
          funding, for revegetation.  Additional plants will be obtained from
          the California Division of Forestry.
                                      255

-------
     3.   Assist State Water Resources Control Board in  planning, restora-
          tion and planting which will be done by California Conservation
          Corps, County or Water Board personnel.

     4.   Collect data on growth and survival and monitor  overall success
          of plantings.

     5.   Special attention was to be paid to the establishment of greater
          vegetation density at the top of highway cuts.
                              3.   Soil Mixes
In an attempt to improve survivability of the plants  for  this demonstration
project, different soil mixes were used.   Standard U.C. mix was used as a
control and comparison for two test mixes.   The U.C.  mix  consists of 1:1:1
ratio of sand, peat and ammoniated redwood sawdust.   The  other two mixes
used were 1:1 peat-vermiculite and 1:1 peat-basalite. Basalite is a granular
clay material which is a manufacturing by-product.  Basalite must be leached
to remove excessive boron before it is incorporated in a  planting mix.  Both
test mixes had the following nutrients supplied per standard six inch pot;
8g dolomite, 2g oyster shell, 2g superphosphate,  3g potassium nitrate.  The
criteria used to determine the desirability of each mix will be the percentage
of plants surviving at the end of the observation period.


                              4.  Containers

Four types of containers were used to compare growth  and  transplant survival
of several species.

The standard container used for all species unless otherwise noted was a
commerical peat pot^'^) 6.25 cm diameter by 7.5 cm deep.
Two sizes reusable, tapered,  deep plastic tubes ^  '^were used.  One was
7.5 cm diameter X 23.75 cm deep.   The other was 1.9 cm in diameter X 13.75 cm
deep.

"Book" planters^ '  ,  ribbed  plastic folders with 4 (four) planting com-
partments, each 3.75 cm X 3.75  cm X 11.9  cm, were the fourth type of
container.  Because of the thin plastic used,  these are usually not re-
usable.
1)   No endorsement is implied.   Commercial names are given for identification
     purpose only.
2)   Jiffy Pot #425.
3)   Manufactured by Crown Zellerbach  Corp., Edwood Nursery, Araura, Ore.
4)   Hillson's Rootainers, Spencer-Lemaire Ind. Ltd.,. Edmonton, Alberta, Canada
                                     256

-------
                            5.   Growing Conditions

Greenhouse temperatures were usually 18 C days,  13 C  nights but  sometimes
greenhouses were used with 21 or 24°C day temperature and 16  or  18°C nights.

Sweatbox conditions for propagation were plastic covered frames  with 21°C
bottom heat located in a lathhouse.

Intermittent mist was on a 5 sec. every 2.5 min. (on  a greenhouse bench)
with bottom heat (24°C).  Both tap water and deionized (DI) water mists
were used.  Tap water was used unless DI is specified.


                             6. Plant Materials
                        Principal Species Investigated
                                    »-
Plant materials grown in larger quantities are listed alphabetically first.
Species grown in smaller quantities are discussed later.

Agropyron trichophorum ('Luna'  pubescent and 'Topar'  pubescent wheatgrasses):

Seeds were sown directly in peat pots the first  week  of April in greenhouses
(18°C day, 13 C nights).  Flats were covered with newspaper for  about 5  (five)
days until the seeds began to germinate.  Plants were ready to plant out
approximately 6 (six) weeks after sowing.

Artemisia caucasica (Caucasica artemisia):

Cuttings were taken from stock plants in June and rooted in small tubes under
mist.  One hundred cuttings were stuck in the mixes previously described.  The
total rooting after six weeks was 83% (250/300).   There was no recorded dif-
ference in rooting between the soil mixes.  The  rooted cuttings  were ready
to plant 10-12 weeks after being stuck.

Artemisia tridentata (Big basin sage):

Seeds were stratified at 2 C for ten days before being sown in flats in the
mist.  This seed, which had been in cold storage for  three years, germinated
within three weeks.  The seedlings were transplanted  approximately 5 (five)
weeks after the sowing date to  small tubes with  the soil mixes listed pre-
viously.  The plants were grown in the greenhouse another two months and in
the lathhouse for six weeks before being moved to the planting site.  Survival
data are given in Table A-l.
                                     257

-------
Table A-l. Artemisia tridentata
Survival in 3 soil mixes
Soil Mix
U. C. Mix
Peat-basalite
P ea t-vermiculite
, 3% months after
Numb er
Planted
40
40
40
transplanting .
Survival
# %
36 90.0
39 97.5
38 95.0
Atriplex gardneri (Gardner valley saltbush) :

Seed which had been in cold storage for four  years was  sown in flats on a
greenhouse bench on 1-27-76.  Within a week the first seeds began germinating.
Seedlings were transplanted within a month (2-20-76) of the sowing date to the
containers and in the soil mixes listed previously.  After approximately
three months growth in the greenhouse the plants were placed  in the lathhouse.
In two months (five months from sowing) the plants were moved to the planting
site.  Survival data at that time were given  in Table A-2.  There were no
consistent differences in survival which could be attributed  to container
size or soil mix.
Table A-2. A trip lex gardneri
Survival in various soil mixes and container types, 5 months
after transplanting.
Soil Mix
UC Mix
Peat-basalite
Peat-DG*
UC Mix
Peat-basalite
Peat-DG*
UC Mix
Peat-basalite
Peat-DG*
Container
small tube
small tube
small tube
peat pot
peat pot
peat pot
book
book
book
Numb er
Planted
100
100
100
40
40
40
40
40
40
Survival
# %
92
89
87
38
36
32
38
39
39
92.0
89.0
87.0
95.0
90.0
80.0
95.0
97.5
97.5
*DG = field collected decomposed granite.
                                     258

-------
Cornus stoloaifera (Creek dogwood):

Cuttings were originally collected  in the spring from plants  in the field.
These were rooted and used for stock plants.

Succulent tip cuttings from stock plants rooted 100% within two weeks.  "Rooted
cuttings grew rapidly in peat pots  and were ready to plant out 6-8 weeks
after sticking.                                                     '   '.. .

Lupinus spp. (Lupines):

Small lots of lupine seed had been  collected in previous years and had  been
in cold storage for varying number  of years.   Most of the seed was not
identified as to species.  Hot (73°C) water was poured over the seeds and
they were allowed to soak in the cooling water.  Unimbibed seed were separated
and treated as above with boiling water.  Still unimbibed seed were separated
and boiled one minute before soaking 24 hours in the cooling water.  Imbibed
seeds were sown in flats, covered with newspapers and placed on a greenhouse
bench.  Germination began after about five days.  At the second leaf stage
the seedlings were transplanted to  peat pots.  They were moved to the lath-
house after two weeks and outside two weeks later.  After about two weeks
outside they were ready to plant.

Considerable additional research on lupine propagation, bacterial inoculation,
direct seeding and transplanting is being done by Mr. David Gilpin as his
master's thesis project.  Results of these studies are not yet available.


Penstemon newberryi (Mountain pride):

Dormant cuttings were taken from field grown plants in the late fall and
early winter of 1975-76.  The cuttings were dipped in 1000 mg/1 IBA for 1-2
seconds and stuck in vermiculite in outdoor sweat boxes.  One flat of cut-
tings that was stuck 12-17-75 had 98% (173/176) rooting after two months.
Of seven flats stuck 1-13-76 to 1-30, 87% (1187/1349) had rooted by 3-22-76.
Most of these cuttings had good top growth and could have been transplanted
at least a month earlier.  These rooted cuttings were randomly planted  in
the three mixes described previously and in three containers:  deep tubes,
small tubes, and 7 cm peat pots.  There were nine replications of 13 plants
per treatment in a complete block arrangement.  The plants were grown in
the greenhouse two weeks, the lathhouse two weeks and then outside in partial
shade until they were transported to the site.  Large, well rooted P. newberryi
cuttings such as these, would reach suitable planting size in about one month
in the small tubes, two months in the deep tubes and about a month and  a half
in the peat pots.

After four to five months growth in the containers survival (Table A-3) was
highest in the deep tubes (346/351) next in the small tubes (336/351) and
least in the peat pots  (307/351).  The plants in the vermiculite peat mix
had the highest survival  (335/351), in regular U.C. mix next (330/351)
and the least survival in the basalite peat mixture  (324/351).  These dif-
ferences are small and probably of no real significance.  Survival data one
year after planting should be compared.
                                     259

-------
Table A- 3
. Penstemon newberryi
Survival in 3



containers

and 3
13
soil mixes,
July &
August, 1976
planted/treatment/rep.
MIX


Rep.
1
H 2
S 3
H 4
w -*
ivi ^
5 o
7
8
9
TOTALS
1
en 9
w ^
g 3
H 4
jj 5
s ^
en 7
8
9
TOTALS
1
2
en 3
S 4
5

-------
Four to six weeks after transplanting these first cuttings,  additional cut-
tings were taken from them.   These softwood (but not succulent) cuttings
were dipped in 1000 ppm IBA for 1-2 seconds and rooted under deionized (DI)
intermittent mist.  Three hundred (300)  cuttings were rooted in vermiculite
and 300 cuttings were stuck directly in  small tubes, 100  of  each  of  the
three mixes previously described.  They  were left 10 days in DI mist, cycle
2.5 sec. every 2.5 min. and ten days on  the hardening off bench.  Rooting
was 100% in all cases.  The cuttings rooted in vermiculite were then trans-
planted on one of the three previously described mixes in 7.5 cm  peat pots.
All cuttings were left in the greenhouse ten days and them moved  to  the
lathhouse.  Thirty days after sticking,  roots were protruding from the bottoms
of the small tubes and the root ball held together although  the tops were
the sides of the peat pots.   After another ten days to two weeks  (total  time,
six weeks) in the lathhouse the direct stuck plants were  ready to plant while
those that were transplanted required another two weeks in the lathhouse
(summer conditions in Davis).

Prunus emarginata (Bitter cherry):

Many propagation techniques have been tried with this species with very
limited success.  Dormant hardwood cuttings in the sweatbox  and leafy simi-
hard wood cuttings under mist have failed to root.  Root  cuttings send up
shoots but do not initiate new roots. These shoots were  excised  from the  root
cuttings, dipped in 4000 mg/1 IBA and rooted under mist about 7%  (4/60)  of the
excised cuttings rooted within three weeks, but four weeks after  sticking  all
cuttings were dead.

Field collected root suckers have rooted somewhat more successfully. Suckers
were taken (on 4-18-76 at approximately  5000 ft. elevation)  before  they
emerged from the ground.  These were rinsed in 1:9 clorox solution and dipped
in 4000 ppm IBA for 1-2 seconds.  They were then stuck (4-23-76)  in  U.C. mix
in two container sizes, with the top of  the cutting just  below the soil  sur-
face.  The containers were placed on a greenhouse bench.   In gallon  cans  there
was no rooting.  Cuttings stuck in deep  tubes showed, Table  D-4,  30% (12/40)
rooting and survival after two months (6-22-76).

Leafy toot suckers (taken 5-17 and 22-76 at approximately 1500 meter elevation)
were dipped (5-31-76) in 4000 mg/1 IBA and stuck in deep  tubes up to the former
ground level on the cutting.  Cuttings just beginning to  show green  were held
in the hardening-off mist bench  (2.5 sec. every 2.5 min)  for two  weeks before
being moved to the greenhouse.  Five weeks after sticking (7-8-76)  they  showed
40%  (8/20) rooting and survival.  Cuttings with more leaves  were  placed  in the
mist bench two weeks and the hardening off mist bench for two weeks  before
being moved to the greenhouse.  Two months after sticking (7-29-76)  they
showed 6%  (3/40 and 2/40) rooting and survival.  These were  limited  trials but
show that propagation by root sucker is  a definite possibility for  this  species.

Preliminary research on germination of Prunus emarginata seeds was  done  in
early 1976.  Comparisons were made between hot and cold water pre-soaking
and three stratification regimes:  21oc, constant; 7 C constant and  a
fluctuating regime of one month at 3 C and four months at 1  C. The results
are shown in Table A-5.
                                      261

-------
Table A-4.
Rooting of Prunus emarginata root suckers under various
conditions .
Treatment*
Greenhouse
Greenhouse
Hardening off
2 wk.
Mist 2 wk.
Hardening off
2 wk.
*A11 were dipped in 4000
Container Date Taken No. Rooted
1 gallon 4/19/76 0
Deep tubes 4/19/76 12/40
Deep tubes 5/17 & 22 8/20
Deep tubes 5/17 & 22 3/40
2/40
mg/1 for 1-2 sec. before sticking.
%
0
30
40 f
7.5
^5


Table A-5.
Response
of Prunus emarginata seeds to hot and cold water

pre-soaking and three stratification regimes.
Week
0*
1
2
3
4
5
6
7
Total
Grand Total
Grand totals
Hot Water
Cold Water
Stratification
210C
0
2
5
2
0
3
0
12
24


Stratification


3°-l°C 7°C
11 0
9 2
1 1
1 0
1 0
4 3
3 2
3 2
33 10
67
21°C
46
21°C 3°-l°C 7°C
7 10 10
9 10 10
0 21
1 12
1 0 1
Oil
220
2 2 2 '"
22 27 27
76
3°_l°r 7°r
J ™"J_ U / l_»
60 37


*Germination when removed from stratification.
262

-------
Hot water does not appear to be more effective than cold  for  soaking  the
seeds and temperature during germination appears unimportant  although the
experiment was not done in such a way that statistical analysis  could be
used on the results.

The higher germination with the fluctuating temperatures  was  the basis of
further tests in 1976-77.

More work was done on germination of Prunus emarginata seeds  in  1976-77.
The seeds have a hard enacarp which may somewhat restrict uptake of water.
They also appear to have an internal dormancy which can be broken by  a
period of moist stratification.  To try to overcome these factors, seed of
P. emarginata were soaked in deionized water for two or eight days and then
stratified in moist vermiculite for five to five and a half months at four
different temperatures (A and B) constant 7°C (C and D) constant 1°C  (E and
F) 7°C for one month and then 1°C for four months or (G and H) 15°C for
one month and then 1°C for four months.  These seeds had  been in cold storage
for four years.  The highest germination of 14% (22/150)  was  obtained with
an eight-day soak followed by one month stratification at 7°C and four month
stratification at 1°C.  The seeds were germinated in the  dark at 21°C on
moist filter paper in petri dishes.  Radical elongation was counted as
germination.  This data is summarized in Table A-6.

The seeds were planted in three different containers.   They grew 100% (40/40)
in deep tubes, 90% (54/60) in small tubes and 77% (31/40) in  peat pots
(see Table A-7).

Purshia tridentata (Antelope bitterbrush):

Three treatments were tried on small lots of Purshia tridentata  seeds.  Those
stratified in moist vermiculite at 2°C for 19 days (3-4-76 to 3-23-76) and
germinated under mist had 93% (28/30) germination within  two  weeks.   (Table
A-8).  Seeds from the same seed lot which had been soaked 24  hours in Gibber-
ellic acid about 60% (18/30) germinated which was slower  and  more erratic than
the germination of the stratified seed.  These seeds had  been in cold storage
for about four years.  Freshly purchased seeds treated with 3% thiourea for
five minutes as per seeds of woody plants of the United States,  had only 2%
(2/100) germination.

Ribes roezlii (Sierra gooseberry):

Fall collected seeds of this species were stratified in moist vermiculite
at 7°C for three months (10-7-75 to 1-12-76).  Half of the seeds were sown
in 1:1 peat/perlite and half in 1:1 perlite/vermiculite.   Since  the seeds
were very small and mixed with debris they were not counted.   After two
weeks in the mist, there were three seedlings in the vermiculite and  one in
the peat.  Two weeks later there were three more in the peat. None of the
seedlings made any further growth and all died shortly.

In mid-May, 1976, a small number (30) of field collected  succulent tip
cuttings were taken.   These were dipped in 2000 mg/1 IBA  for  1-2 seconds,
stuck in vermiculite, and placed in the mist.  There was  no rooting.   Due
                                     263

-------
Table A-6. Response of Prunus emarginata seeds to soaking times and
temperature during stratification. Fall, 1976.
Totals for 6 replicates of 25 seeds each.



Treatment
A. 2-day soak-7°C strat
B. 8-day soak-7°C strat
C. 2-day soak-l°C strat
D. 8-day soak-l°C strat
E. 2-day soak-7°C& 1°C strat
F. 8-day soak-7°C& 1°C strat
G. 2-day soak-15°C & 1°C
strat
H. 8-day soak-15°C & 1°C
strat

A. & B. 7°C strat
C. & D. 1°C strat
E. & F. 7°C & 1°C strat
G. & H. 15°C & 1°C strat
Aj C, E & G 2-day soak

No . Germinating
per Week
123456
000000
400000
301200
300100
210000
780222

3 0 0 0.0 2

320202
Summary Totals
400000
601300
990223
620204
811202
B, D, F, & H 8-day soak 17 10 0 5 2 5
GRAND TOTAL 25 11 1 7 2 7


Total
No.
0/150
4/150
6/150
4/150
3/150
21/150

5/150

9/150

4/300
10/300
25/300
14/300
14/600
34/600
53/1200



%
0
2
4
2
2
14

3

6

2
3
8
5
2
7
4
Germination
During
Stratification
%
1
5
2
2
3
7

3

2








Table A-7.
Containers
Peat pots - 2
Small tubes -
Peep tubes - 2
Survival of Prunus emarginata seedlings in 3 containers.
Spring, 1977.
Mean No.
Surviving
replications of 20 each 15.5
3 replication of 20 each 18.0
replications of 20 each 20.0

Sx %
2.1 77
1.0 90
0.0 100
264

-------
Table A-8.     Purshia tridentata seed response to several  pre-germination
               treatments.   Spring 1976.
                                 # Seed Germinated
     Treatment
//planted  Wk. 1     Wk.2   Wk.3   Wk.4  Wk.5  Final %
Stratified 19         30      25
days @ 2QC

50 mg/1 GA, 24 hrs.   30       5

3% Thiourea          100       1
5 minutes
                    28     28      28    28    93


                     9     15      16    18    60

                     22       222
to the low spreading habit of this species and its ubiquity in dry rocky
places more work should be done toward propagating it.

Ribes viscosissimum (Sticky currant):

Fall collected seeds of this species (tentatively identified as Ribes
viscosissimum) were stratified for five months in moist vermiculite at 7°C.
They were sown on a flat and placed in the mist for two wee~ks.  Germination
was fair and six weeks after sowing the seedlings were transplanted to 7.5 cm
peat pots.  Tip cuttings taken from the seedlings in early June (four months
after sowing) rooted 100% under mist and grew so rapidly that cuttings could
be made from them within six weeks.

Salix spp. (Varous Willow species):

Dormant cutting material of Salix  lemmonii (Lemmon willow) and S. lasiandra
 (western block willow) was collected from the field in early December, 1975,
and kept in cold storage until the hardwood cuttings were made.  The four-inch
long cuttings were stuck in flats  of vermiculite and placed in unheated cold
frames in a lathhouse by mid-January, 1976.  Rooted cuttings were transplanted
into deep tubes and peat pots with UC mix within four months of the sticking
date.

Observations were made on the rooting ability as it related to the diameter
of the cuttings and as it was affected by a hormone dip (1000 mg/1 IBA for one
minute).  In general, for both species, the large diameter cuttings (1.25 cm
to 1.9 cm) had a higher rooting percentage (see Table A-9) than the medium
 (1.0 cm to 1.25 cm) or the small  (0.6 cm) diameter cuttings.  Cuttings of
both species dipped in the IBA had a lower,rooting percentage than those
not treated with the hormone.

Cutting material of four species,  S. rigida, Brittle willow, S. lasiandra,
Western black willow, S. scouleriana, Scouler's willow, S. lemmonii, Lemmon
willow, was collected in mid-December, 1976, from sites at the south end of
 the Tahoe Basin.  Cuttings were made during the two days following the
                                      265

-------
Table A-9. Effect of hormone and cutting diameter on rooting of
lemmonii and S. lasiantra.

Salix lemmonii
Cutting Diameter
0.6 cm-small
1.0 cm - 1.25 cm -
medium
1.25 cm - 1.9 cm -
large
Total
Salix lasiandra
Cutting Diameter
0.6 cm - small
1.0 cm - 1.25 cm -
medium
1.25 cm - 1.9 cm - ~
large
Total

No IBA
22/30
29/30
29/30
80/90
No IBA
19/30
28/30
27/30
74/90


HORMONE TREATMENT
% 1000 mg/1 IBA %
73.3 12/30
96.7 16/30
96.7 17/30
88.9 45/90
40.0
53.3
56.7
50.0
HORMONE TREATMENT
% 1000 mg/1 IBA %
63 15/30
93 18/30
90 24/30
82.2 57/90
50
60
80
63.3

Total
34/60
45/60
46/60

Total
34/60
46/60
51/60

Salix

%
56.7
75.0
76.7

%
56.7
76.7
85.0

collection from the field, and stuck on the third day.  The cutting diame-
ters, media, and rooting environments were the same as in 1975.

The results did not have the same consistent pattern as in 1975-76 where the
larger diameter cuttings had a higher rooting percentage than the medium or
smaller diameters.  Generally, there were higher rooting percentages on cut-
tings not dipped in 1000 mg/1 IBA than those that were given a one minute dip.

S. scouleriana in all treatments had considerably lower percentages of root-
ing.  This species was the slowest to root and to make new growth.  The new
leaves were infected with insect galls that were treated with Isotox.  There
was more noticeable growth after two sprays of Isotox two weeks apart.  Well
rooted cuttings (roots 5-10 cm long) were transplanted to containers during
the first week of March (approximately three months after sticking).  Trans-
planted cuttings grown in'the lathhouse in deep tubes could fill the container
in 2 to 2% months (= early to mid-May).

Symphoricarpus acutus (Creeping snowberry):
               i
In mid-May, 1976 a small number of softwood cuttings were taken from stock
plants of this species.  The cuttings were dipped in 2000 mg/1 IBA for 1-2
                                     266

-------
seconds and then stuck in vermlculite.  About 95% of the cuttings rooted
within three weeks under mist but all dropped their leaves.  When trans-
planted most of the cuttings  failed to  resprout and all died.
                            7.  Plant Materials
                         Other  Species Investigated

Very limited propagation trials were conducted  on a  number of other species.
Some of these should be good candidates for revegetation  of  disturbed sites
and further work is warranted.   The trials were limited by both  time and
financial constraints and often by the availability  of seed  or cutting mater-
ial.  Brief summaries of these  trials follow.
Amelanchier alnifolia (Western serviceberry):

Seeds were stratified at 7 C for three months.
24 plants survived to planting size stock.

Arctostaphylos patula (Greenleaf manzanita):
Of 48 seeds that germinated,
This species has been more difficult to root than A.  nevadensis.  More work
is needed on both species.  Rooting of the latter species  has  been variable
from year to year and for cuttings from different location.  It may  be that
variables in microsite (soils, rainfall, etc.)  may have a  strong  influence
on rooting.  This hypothesis should be tested by growing stock plants under
controlled conditions of irrigation and fertility.

Atriplex canescens (Four-winged saltbush):

Seeds sown directly in peat pots on February 10, 1977 produced good  planting
stock under greenhouse conditions in two months.  Plants need  cutting back if
held in these conditions more than two months.   It is recommended that 5-7
seeds be sown per pot and these be thinned to one seedling per pot at an
early age.

Castanopsis sempervirens (Bush chinquapin):

Viable seed was unobtainable during 1975-1976.   Dormant cuttings  calloused
heavily but only four plants of over 50 cuttings rooted.  This indicated that
it is possible to root the species but better treatments need  to  be  developed.
Cutting back stock plants to force juvenile growth and the use of softwood
cuttings should be investigated.

Ceanothus cordulatus  (Mountain whitethorn):

Trials with both seeds and dormant cuttings were essentially unsuccessful
with less than 0.1% success.  This species is widespread in California moun-
tains.  Additional work with fresh seed from different sources is warranted.
Softwood cuttings should be tried also.
                                      267

-------
Table A-10.
Salix spp. Comparison
Salix as inf

S. rigida:
Treatment*



Replications
1 679
2 977
3 958
4 10 8 10
5 752
6 10 9 10
S. lasiandra:
1
2
3
4
5
6
S. scouleriana:
1
2
3
4
5
6
S. lemmonii:
1
2
3
4
5
6
7
9
8
8
9
8
5
1
2
4
1
1
8
4
7
9
7
9
10
9
6
9
8
10
5
2
6
4
4
4
8
7
9
9
7
7
8
10
7
9
8
10
0
4
3
6
3
4
4
5
6
7
10
9
luenced by
Total
22
23
22
28
14
29
25
28
21
26
25
28
10
7
11
14
8
9
20
16
22
25
24
25
of rooting of several species of
cutting diameter and hormone treatment.
small
medium
large
small
medium
large
small
medium
large
small
medium
large
-IBA %
23/30 76.7
28/30 93.3
29/30 96.7
-IBA %
28/30 93.3
26/30 86.7
28/30 93.3
-IBA %
7/30 23.3
14/30 46.7
9/30 30.0
-IBA %
16/30 53.3
25/30 83.3
25/30 83.3
+IBA %
22/30 73.3
22/30 73.3
14/30 46.7
+IBA %
25/30 83.3
21/30 70.0
25/30 83.3
+IBA %
10/30 33.3
11/30 36.7
8/30 26.7
+IBA %
20/30 66.7
22/30 73.3
24/30 80.0
Treatments
Total Species:
S. rigida
S. lasiandra
S. scouleriana
S. lemmonii
*Treatments: 1.
2.
3.



0.6 cm
0.6 cm
1.0 cm
1000
1
22
25
10
20
dia.
dia.
- 1.
mg/1
2 3
4
23 22 28
28 21 26
7 11 14
16 22 25
+ 1000 mg/1 IBA
, no IBA
25 cm dia. +
IBA
5 6
14 29
25 28
8 9
24 25
4. 1.0 cm - 1.
5. 1.25 cm - 1
1000 mg/1
6. 1.25 cm - 1
25 cm dia., no IBA
.9 cm dia. , +
IBA
.9 cm dia. , no IBA
268

-------
Chrysothamnus nauseosus  (Rabbit brush):

This species is easy to  grow by direct sowing about ten seeds per pot and
thinning to one or two plants after germination.   One problem that must be
recognized is that in some years,  early  fall frosts when  the plant is in
flower, result in a crop of non-viable seed.

Eriogonum unbellatum (Sulphur flower):

Cuttings under mist (March 1977) all rotted.  The use of  a  sweat box should
be tried with this species.

Seeds were sown directly in several sized containers, 3-6 seeds per container
and covered with newspaper.  Seed was of poor quality with  many hollow  (aborted
seeds).  Of 574 containers, over 450 had at least one seedling.  Seedling
propagation is rapid and good plants can be produced in three to four months.

Holodiscus bousieri (Cream bush):

No cuttings of this plant rooted when taken as dormant cuttings.  Softwood
cuttings should be tried in June.

Lonicera conjugialis (Double-flowered honeysuckle):

A limited quantity of seed was available.  These were stratified for three
months at 7°C.  Of 64 which germinated only 20 survived transplanting and
the subsequent growing period.  Cultural conditions  (media, container size,
etc.) need more investigations.

Penstemon strictus  (Rocky Mountain penstemon):

This  penstemon rooted well from cuttings.  Other species  of penstemon native
to  the Sierras should also be tried.

Rhamnus rubra  (Sierra coffeeberry) :

Three months stratification at 7 C resulted in good germination.  Of 296
seedlings transplanted,  284 survived to  transplanting size.  This is a  good
candidate for revegetation.  Cutting propagation of dormant wood was unsuc-
cessful.  However, softwood cuttings of  this species are  being  used by
commericial nurseries.

Ribes cereum  (Squaw currant):

A limited number of seeds were stratified for four months at 7  C.  At the
end of stratification 24 were germinated.  Twenty of these survived to  plant-
ing size.  The remainder of the seeds were sown and an  additional 40 plants
resulted.
                                      269

-------
Ribes nevadensis (Sierra currant):

Stratification for six months at 7°C resulted in  good germination.  A
shorter stratification period (perhaps 3-4 months) probably would be adequate
because nearly 300 seeds had germinated while being  stratified.  Dormant
cuttings rooted well but survival after transplanting was poor.  Softwood
cuttings should be tried.

Rosa woodsii var. ultramontana (Mountain rose):

A small number of s.eeds were stratified for  five  months at 7 C.  Thirty-six
seeds germinated.  A cutting propagation trial using dormant wood of two
diameters and several hormone levels (324 cuttings)  did not produce any
rooted plants.  This is surprising in view of the ease of rooting of most
species of roses.  Softwood cuttings should  be tried in June or July.

Rubus parviflorus (Thimble b erry):

This species is an invader of highway cuts and talus slides in some parts
of the basin.  Limited trials with both softwood  and dormant cuttings have not
been very successful.  The genus Rubus generally  roots well with some species
rooting whenever a tip touches the ground.  Because  of its potential for
revegetation additional research is warranted.  One  approach would be the
use of root cuttings.

Sambucus microbotrys (Red elderberry):

This species roots readily from softwood cuttings and no new research was
conducted on the propagation of it.


                             8.  Outplantings

The plant materials were delivered to the site as needed.  Planting was done,
for the most part by State Board crews.  Because  U.C. personnel were not on
site during all planting operations, mapping of plantings was largely the
responsibility of the State Board personnel.  Planting locations are summa-
rized in Appendix B.

A large planting of Penstemon newberryi was  done  by  U.C. personnel.  This
experiment was to compare field survival of  this  species which had been grown
in different media and container sizes.  Description of the media and container
sizes is at the beginning of this report.

Data was to have been taken in May-June of 1977.   Due to the lateness of the
growing season and the covering of many plants by the soil material, valid
counts could not be made prior to the termination date.  This species has
the ability to survive some burial and grow  through  it.  This survival data
species which were delivered to' and planted  at the Rubicon Properties erosion
control project site is given in Table A-11.  Plantings were conducted in the
summer and early fall of 1976 (5,876 plants) and  the spring of 1977  (14,484
plants).
                                     270

-------
TABLE A-ll
INVENTORY OF PLANT MATERIALS
DELIVERED TO RUBICON PROPERTIES
EROSION CONTROL PROJECT SITE
Species
Arctostaphylos nevadensis
Artemisia caucasica
Artemisia tridentata
Atriplex gardneri
Ceanothus prostratus
Composite (Purple)
Composite (Yellow)
Cornus stolonifera
Grasses (assorted sp)
Lupinus spp.
Penstemon newberryi
Primus emarginata
Purshia tridentata
Ribes viscosissimum
Symp ho ri carpus acutus
Nama lobbii
Total
Species
Amelanchier alnifolia
Arctostaphylos
nevadensis
Arctostaphylos patula
Artemisia tridentata
Atriplex canes cens

Delivered Summer 1976
7-13 7-27 8-4
8 1
5
31 11 82
490
133
122
14
320 160 420
72 64 77
448 139 761
19
21 21
24
5
1
962 1014 1473
Delivered Spring 1977
Container 5-11 5-23 6-3
book 24 10
gallons 5
peat pots 105
deep tubes 10
gallons 2
peat pots 24
peat pots 400
books 568
small tubes 110
deep tubes 22 35
8-11
31
131
4
64
10
1208
130
31
54
1663
6-20
6
75
8-23
250
12
360
18
124
764
Total by
Container
& Species
34
5
111
10
2
99
400
568
110
57
Total
by
Species
40
255
124
490
264
4
186
36
2108
213
1838
19
73
96
129
1
5876
Total
by
Species
34
5
124
99
1135
271

-------
Table A-ll.
Inventory delivered Spring 1977 (Con't):
Species
Castanopsis sempervirens
Ceanothus cordulatus

Ceanothus prostratus




Chrysothamus nauseosus
Cornus stolonifera
Erigonium umb ellatum


Lonicera conjugialis

Lupinus breweri


Lupinus fulcra tus


Lupinus grayi


Lupinus sellulus


Luna pubescens

Penstemon newberryi



Container 5-11 5-23 6-3
deep tubes 1
books 2
deep tubes
peat pots 120 64
books 156 84 640
small tubes 100
deep tubes 125
gallons 3
peat pots 456 75 125
deep tubes 39
peat pots 126 42
books 175
small tubes 70
peat pots 2
books 20 2
peat pots 36
books
deep tubes
peat pots 36
books
deep tubes
peat pots 37
books
deep tubes
peat pots 37
books
deep tubes
peat pots 1760 380 40
books 672 960 240
peat pots 720 265 53
books 84
small tubes 930 180
large tubes 360 15
Total by
Container
6-20 & Species
1
2
13 13
70 254
800
100
125
3
30 686
39
8 176
175
70
2
22
36
50 50
30 30
36
50 50
40 40
37
50 50
25 25
37
50 50
15 15
2180
1872
1038
100 184
1110
375
Total
by
Species
1
15

1362




686
39
421


24

116


126


112


102


4052

2707



272

-------
Table A-ll.
Inventory delivered Spring 1977 (Con't):
Species
Penstemon stricta
Prunus emarginata
Purshia tridentata
Rhamnus rubia
Ribes cereum
Ribes nevadensis
Ribes roezlii
Ribes viscosissimum
Rosa woods ia
Rubus parviflorus
Salix spp.
Symphoricarpus spp.
Total by date
Container 5-11
peat pots 80
books 92
gallons
peat pots 4
books 8
large tubes 75
gallons 3
peat pots
books
small tubes
large tubes
books 284
books 20
deep tubes
peat pots 3
peat pots 6
deep tubes
gallons
peat pots
peat pots 12
books
deep tubes
books
5117
Total by Total
Container by
5-23 6-3 6-20 & Species Species
88
4
38 ' 135 410
165 450
5
23 26 10
35 73
500
300
100
20
35
5
2 150
7 1
1
1
30
1 1
48
9
65
4508 1378 1681
168
92
4
587
623
80
62
108
500
300
100
304
55
5
155
14
1
1
30
14
48
9
65
264
1352
1008
304
60
155
15
1
30
14
57
65
14484
                                9.   Summary

Advice to project personnel on planning and site preparation was accomplished
in 1976 by several trips  to the site by the principal investigator during the
spring and summer.  It was  not possible to take spring survival data by the
                                     273

-------
termination date of the project because of the unusually late  spring.  Plants
which were partially buried and some deciduous material could  not have been
counted with any degree of validity as late as the week of June  20,  1977.

There is much additional information on procedures and plant materials for
revegetation in the Tahoe Basin in:

          "Revegetation of Disturbed Soils in the Tahoe Basin"

           Andrew T. Leiser, James J. Nussbaum, Burgess Kay,
           Jack Paul, William Thornhill

           Final Report, March 1971 - June 1974
           CA-DOT-TL-7036-1-75-24

           Sponsoring Agency:
           California Department of Transportation
           Transportation Laboratory, Sacramento, Calif.

Scheduling of plant production is detailed in part under the various plant
species section of the report.  The plant species vary in the  length of
time required to produce stock suitable for out-planting.  Longer growing
time is required to produce adequate root systems in the deeper  containers.
A summary of several production schedules with examples of species which
might be grown in each is as follows.  Dates given are lead time prior
to planting.
Seed Collection:
Seed Production-Slow Growing Species

               Greenhouse Production

               Summer-Fall-12-8 mo.
Stratification:
Germination, Transplanting:

Growing-on:
               Winter, 8-6 mo.
               Late Winter, 6-4 mo.

               Spring, 4-2 mo.
Field Production

Summer-Fall, 24-16
  mo.

Winter, 16-14 mo.
Late Winter,
  14-12 mo.
Spring-Summer,
  12-10 mo.
The field production will produce larger plants,  4"  to "gallon"  can  size and
will be higher in cost for the'"gallon"-can size.

Examples: Prunus emarginata, Ribes spp., Penstemon spp.,  Ceanothus spp. etc.
(the more woody spp. for the most part).
                                     274

-------
                    Seed Production-Rapid Growing Species
Seed Collection:
                                   Greenhouse Production
                                  Summer-Fall, 12-8 mo.
Field Production

Summer-Fall, 12-8
  mo.
Stratification:                    Non required  for most.

Germination:                       4-3 mo.                  5-4 mo.
Growing on:
                                   3-2 mo.
4-3 mo.
Examples:  Grass sp.,  Atriplex spp., Artemisia  spp., Chrysothamum nauseosus,
Eriogonum umbellatum,  Purshia tridentata, Lupinus  spp.  (Herbaceous,
suffrutescent and rapid—growing woody  species for  the most part).

                             Cutting Production

                      Soft-wood Cuttings-Outdoor Stock Plants

                    May-July, 12-10 mo.

                    May-Aug., 12-9  mo.

                    June-Fall and Late Winter-Early Spring

                    April-through Summer
Take cuttings:

Roo ting:

Growing on:

Finished plants:
                 Soft-wood Cuttings-Greenhouse Stock Plants

Take cuttings:      Jan-March,  6-3 mo.

Growing on:         Feb.-June,  5-2 mo.

Finished plants:    May through Summer

Examples:           Easy to root species,  eg.  Penstemon, Salix etc.
Take cuttings:

Rooting:

Growing on:
                               Dormant  Cuttings

                    Sept.-November,  10-7 mo.

                    Requires  1-4 mo.  depending on  species

                    (Greenhouse in colder months)
                    2-5 mo.
                    Note:   If grown out-of-doors and/or larger plants are
                           required,  one full growing season is required
                           and lead time becomes 22-19 mo.
                                     275

-------
                                 10.  Costs
Production of plants for revegetation involves three basic steps.  1)  Seeding
or collecting and preparing cuttings, 2) rooting the cuttings,  or  germinating
the seed, 3) transplanting the seedlings or rooted cuttings to  containers
and growing them to large enough size for outplanted.  The following  dis-
cussion and tables presents the costs associated with each of these steps.
The final table gives the total cost of producing plants for revegetation.

These cost estimates include some of the many variables which affect  plant
production.  The factors include difficulty of collecting cuttings, size of
cuttings, percentage rooting, rooting time, type of container and  time re-
quired to grow to size.
Seeding

Seed cost per unit is very small.  Unit cost includes direct
seeding and thinning to desired number per pot.
                                                                 Unit Cost
                              $  0.03
Collecting and Preparing Cuttings

Cost of collecting cuttings in the Tahoe Basin from Davis, California:
          2 man-days @ $8.00/hr.
          1% days per diem @ $35.00
          Mileage, 500 km. @ 0.9
          Supplies: ice, bags, labels
          $128.00
            52.00
            45.00
             3.00
          $228.00
Number of cutting collected in one trip varies from 5,000 to 10,000 depending
upon ease of collection.
          Collection Unit Cost:
     High (5,000/trip)
     Low (10,000/trip)
          Preparing and sticking cuttings
          Materials cost: media and pro-rata flats
          Preparation Unit cost:   Large cuttings @ 100/flat
                                   Small cuttings @ 150/flat
        $ 0.045
          0.023

          0.03

          0.015
          0.010
 Summary of Cutting Collection and Preparation Costs

                                   Low Cost
 Cost  of  collecting cuttings
 Cutting  preparation
 Material large cuttings
 Small cutting

   TOTAL  Large cuttings
         Small cuttings
$0.023
 0.030
 0.015
 0.010

 0.068
 0.063
High Cost

$ 0.045
  O.Q30
  0.015
  0.010

  0.090
  0.085
                                      276

-------
Rooting Cuttings

The unit cost of rooting a cutting depends on the propagation space  required
and the weeks required for adequate rooting.

Costs are based on 35 cm X 55 cm X 8.75 cm flats, prorated for the life  of
the flat.  One medium, vermiculite (not reusable) is used as  an average
cost.  Large cuttings @ 100/flat are about 538 cuttings/sq. meter.  Small
cuttings @ 150/flat are about 807 cuttings/sq. meter.  Figures are given for
two propagation environments, a greenhouse mist requiring four or six weeks
for rooting and a lathhouse sweatbox requiring eight or twelve weeks for
rooting.
Table A-12.    Total Cost of Rooted Cuttings ($)
Environment
Rooting Time
Cost of Collecting Cuttings
     Greenhouse Mist
  4 Weeks
Low | High
6 Weeks
Low | High"
                                                            Lathhouse Sweatbox
8 Weeks
Low I High
12 Weeks
Low|High
A.   LARGE CUTTINGS

Cost, stock cutting           .068 .090      .068 .090
Propagation space/maint.      .025 .025      .037 .037

TOTAL: 100% Yield             .093 .115      .105 .127
        80% Yield             .116 .144      .131 .159
        60% Yield             .155 .192      .175 .212
        40% Yield             .232 .288      .263 .318
                             .068 .090 .068 .090
                             .030 .030 .045 .045

                             .098 .120 .113 .135
                             .122 .150 .141 .169
                             .163 .200 .188 .225
                             .245 .300 .283 .338
B.   SMALL CUTTINGS

Cost, stock cutting           .063 .085      .063 .081
Propagation space/maint.      .017 .017      .025 .025
TOTAL:  100% Yield            .080 .102      .088 .110
         80% Yield            .100 .128      .110 .138
         60% Yield            .133 .170      .147 .183
         40% Yield            .200 .255      .220 .275
                             .063 .085 .063 .085
                             .020 .020 .030 .030
                             .083 .105 .093 .115
                             .104 .131 .116 .144
                             .138 .175 .155 .192
                             .208 .263 .233 .288
 Growing Costs

 The  following are costs associated with transplanting rooted cuttings to con-
 tainers, and growing cuttings or seedlings up to a usable size.  The following
 basic costs are used in the calculations.
                                      277

-------
Greenhouse space and maintenance-
Lathhouse space and maintenance-
Medium (potting mix)
  Sand @ $7.85/cubic meter  =
Ammonized Redwood Sawdust-
  fa $3.50/cubic meter
Peatmoss two bales @ $8.00
Fertilizers
Labor, steam sterilizing
                                      $13.45/sq. meter
                                        8.07/sq. meter

                                        2.00

                                        7.00
                                       16.00
                                        2.00
                                       20.00
             2/Mo.
             2/Mo.
                                       $47.00
                              Cost per Cubic Meter $18.81
Containers

Peat Pots
Books^
Large tube
Small tubes
                        Cost/100 Units

                             $2.64
                              3.75
                             18.75
                              3.75
Estimated Reuse

     No
     No
     5X
     5X
    Net
Gost/100 Units

     $2.64
      3.75
      3.75
       .75
Total Production Cost

The total cost of producing plants for revegetation can be calculated  from
the preceding tables.  The total cost of producing direct seeded  container
plants can be calculated by adding the seeding cost +_ $.03 per plant to  the
growing cost in Table A-13.  The total cost of producing plants from cuttings
can be calculated by adding the cost of a rooted cutting from Table A-12 to
the growing cost from Table A-13.  Note, however; that large  cuttings  cannot
be transplanted into the small tubes.

                                 Discussion

In our tests, the 7.5 cm deep peat pots have been used for all species.
Growth is this particular design which is 1.25 cm deeper than the standard
6.25 cm peat pot has been generally good.  The greater depth  is superior to
the shallow peat pot for the native plant spectrum.  Some problems of  drying
out are encountered when plants are moved to the field.
                                 Commercial names are given for identification
1.   No endorsement is  implied.
     purposes only.
2.   Jiffy Pot #425.
3.   Hillson's rootainers,  four  compartments  each, Spencer-Lemaire, Inc.
     Ltd., Edmonton,  Alberta,  Canada.
4.   Tubes, large,
            small,  in block of 100  units.
     Crown Zellerbach Corp., (Ed Wood Nursery) Aurora, Oregon.
                                     278

-------
TABLE A-13
Growing Cost Summary - Unit
Container Greenhouse
3 Months | 6 Months
Peat=Pot 1»2 $0.23 $0.41
Books !»3 0.15 0.21
Tube, large !>4 0.26 0.45
Tube, small l>^ 0.04 0.06

Cost


Greenhouse
3 Mo.,
$0
0
0
0
Lath 3 Mo.
.34
.18
.37
.05
                      Range of  Total Production Costs
                                       High     Low
               Direct seeding
               Large cuttings
               Small cuttings
$0.07 -  $0.48
$0.50 -  $0.79
$0.12 -  $0.74
The deep tubes require a longer growing period to  obtain adequate  root systems
than do the peat pots or books.  The large tube is more difficult  to plant
because of its depth.  More work is  required on cultural practices with  the
1.9 cm tube to determine which species  perform well  in them.  Many cuttings
are too large to transplant into them.   They have  been very good for
Penstemon newberryi where unrooted cuttings are stuck directly  into them and
then rooted.

The books have been very satisfactory.   A larger sized book is  available for
larger plants.  Costs of some larger sized books would be  comparable to  the
large tube in terms of soil used, growing space etc.
                                     279

-------
                                APPENDIX B
                    EROSION CONTROL PLOT DESCRIPTIONS
Number                                                               Page
                                  FIGURES

B-l       SCS Seedings and Plantings, 1973 - 1974,  Northstar 	     281

B-2       Revegetation Plots, 1975- 1976, Northstar 	     290

B-3       Herbaceous Seedings and ¥oody Plantings,  1976,  Rubicon
          Properties	     300

B-4       Shrub and Tree Plantings,  1977, Rubicon Properties 	     318


                                  TABLES

B-l       SCS Shrub Plot Descriptions,  1973 - 1974,  Northstar	     282

B-2       SCS Herbaceous Plot Descriptions, 1973  -  1974,  Northstar     286

B-3       Revegetation Plot Descriptions, 1975 -  1976, Northstar  .     291

B-4       Herbaceous Seeding and Woody  Planting Plot Descriptions,
          1976,  Rubicon Properties	     301

B-5       Plot Description Symbols For  Interpretation of  Tables
          B-3 and B-4 	     313

B-6       Shrub and Tree Plantings Section Descriptions,  1976,
          Rubicon Properties 	     319
                                     280

-------
HERB-6 ,1973
HERB-
                      -HERB
                           12
                            I POND
              HERB-7,1974
                  LOCATION  OF
      4  SHRUB  PLANTINGS
                                   AND
                    HERBACIOUS
                        SEEDINGS
                             BY  THE
                                  SOIL
               CONSERVATION
SHRUB-4,1973
   HERB-5,1973            SERVICE
               AT  NORTHSTAR
                             SPRING
                      1973,  .1974
                 HERB -8,1974
                     HERB-I, 1973
                      HERB-9, 1974
                        HERB-10,1974
                         HERB-II, 1974
                 HERB-4,1973;
                  SHRUB-3, 1973
                    SHRUB-2,1973
                      SHRUB-8, 1974
  NOT  DRAWN  TO  SCALE
                                HIGHWAY 267
                               SHRUB-7,1974

                                •SHRUB-1,1973

                               TRUCKEE—
  HERBACIOUS SEEDING RAIL-  45 KG/HECTARE
  WOOD FIBER MULCH RATE -1350 KG/HECTARE
  16-20-0  FERTILIZER RATE - 560 KG/HECTARE
                                             STATE  OF  CALIFORNIA
                                       STATE  WATER RESOURCES CONTROL BOARD
                   SCS  SEEDINGS
                  AND  PLANTINGS
                                      DEMONSTRATION  OF EROSION AND
                                  281

-------
                                    TABLE B-l

       SOIL CONSERVATION SERVICE TEST SHRUB PLANTING PLOT DESCRIPTIONS
                        SPRING 1973, 1974 - NORTHSTAR
PLOT NO.
SHRUB 1;  South facing cut adjacent to sales office.  Planted Spring 1973.
          150 Ceanothus prostratus; 30 vertical rows, 5 plants/row, 2 ft.
          spacing, 70 survived until 1975, 63 until 1977.
SHRUB 2;  Northwest fill facing.  Planted Spring 1973.
          # Planted
              10    Chryso thamnus nauseosus
              10    Ceanothus prostratus
              10    Ceanothus prostratus
              10    Arctostaphylos patula
              10    Arctostaphylos uva— ursi
              10    Artemisia caucasia
               7    Eriogonum umbellatum
              10    Penstemon strictus
 Survival
1974   1977
(8)
(5)
(4)
(5)
(4)
(1)
(7)
(9)
(8)
(3)
(2)
(1)
(0)
(1)
(6)*
(8)*
          Note:  Spacing is 1.0 meter, 8 vertical rows.  Rows listed left to
          right facing slope from Northstar Drive.
SHRUB 3:  North facing cut across from Plot No. SH-2.  Planted Spring 1973.

          # Planted
               6    Caragana arborescens
               6    Caragana arborescens
               7    Myrica pennsylvanica
               7    Syringa vulgaris
1974
(6)
(6)
(0)
(4)
1977
(6)
(6)
(0)
(4)
          Note:  Spacing is 1.5 meter, 2nd and 3rd rows are 2.0 meters apart.
          Vertical rows listed from left to right facing fill from road
          surface.
SHRUB 4:  North facing fill near small creek.  Spring 1973.

          # Planted
               5    Ceanothus prostratus
               5    Chrysothamnus nauseosus
               5    Chrysothamnus nauseosus
               4    Chrysothamnus nauseosus



* Reseeding and spreading profusely
1974   1977
(2)
(3)
(3)
(2)
(1)
(3)
(2)
(2)
                                      282

-------
TABLE B-l continued
SHRUB 4:
# Planted
5 Artemisia' tridentata
5 Artemisia tridentata
5 Artemisia tridentata
3 Caragana arborescens
2 Artemisia tridentata
5 Atriplex canes cens
5 Atriplex canescens
5 Ceanothus cordulatus
4 Ceanothus cordulatus
5 Caragana arborescens
5 Juniperus conferta
5 Kochia prostrata
4 Arctostaphylos patula
5 Penstemon newberryi
5 Penstemon newberryi
5 Purshia tridentata
5 Purshia tridentata
5 Purshia tridentata
2 Purshia tridentata
5 Rhus trilobata
5 Rhus trilobata
4 Rosa woodsii (cut)
5 Rosa wichuriana
5 Salix gracilis
5 Salix purpurea
Note: Spacing 1.22 meter, 28 vertical rows
left facing slope from Northstar Drive.
SHRUB 5: South facing fill near West Martis Creek.
# Planted
10 Ceanothus prostratus
Note: 1.0 meter spacing, 2 vertical rows.
SHRUB 6: Northeast facing cut on Big Springs Drive.
# Planted
6 Ceanothus prostratus
5 Ceanothus prostratus
4 Artemisia tridentata
Survival
1974 1977
(5) (5)
(5) (5)
(4) (3)
(2) (2)
(2) (2)
(2) (1)
(2) (1)
(5) (4)
(3) (4)
(3) (2)
(4) (1)
CD CD
(3) (3)
(5) (3)
(4) (3)
(5) (5)
(5) (5)
(5) (5)
(D CD
(1) (0)
CO) (0)
(4) (3)
(5) (4)
(5) (5)
(5) (5)
Rows listed right to
Spring 1973.
1974 1977
CO) (0)
Spring 1973.
1974 1977
(2) (?)
(2) C?)
(3) (?)
Note: 3 vertical rows, rows 1 and 2 plants are 1.0 meter apart,
row 3 plants are 1.2 meter apart. Rows listed left to right facing
cut from road surface.
283

-------
TABLE B-l (continued)
SHRUB 7: South facing cut near Northstar entrance. Spring 1974.
# Planted
A. 4
3
5
3
7
5
1
B. 4
2
1
3
5
2
C. 5
5
1
2
5
3
3
D. 10
1
3
8
5
2
1
Survival
Artemisia tridentata
Ceonothus velutinus
Chrysothamnus nauseosus
Eriogonum umbellatum
Artemisia tridentata
Penstemon newberryi
Arctostaphylos nevadensis
Penstemon newberryi
Artemisia tridentata
Arctostaphylos nevadensis
Ceanothus cordulatus
Penstemon newberryi
Eriogonum umbellatum
Artemisia tridentata
Penstemon newberryi
Arctostaphylos nevadensis
Ceanothus velutinus
Chrysothamnus nauseousus
Ceanothus velutinus
Ceanothus cordulatus
Penstemon newberryi
Arctostaphytos nevadensis
Erigonum umbellatum
Artemisia tridentata
Ceanothus consulatus
Ceanothus velutinus
Quercus vaccinifolia
Note: Parts A, B, C planted in horizontal rows as
planted at random. See location map.
SHRUB 8: Northwest facing fill adjacent to Northstar Drive.
# Planted
A. 5
5
5
5
5
5
5
Penstemon strictus
Penstemon strictus
Penstemon strictus
Arctostaphylos uva— ursi
Rosa woodsii
Rosa woodsii
Cornus stolonifera


1977
(1)
(0)
(0)
(3)
(2)
(0)
(0)
(0)
(2)
(0)
(0)
(0)
(2)
(0)
(0)
(0)
(0)
(0)
(0)
(0)
(D
(0)
(3)
(2)
(0)
(D
(D
listed. Part D
Spring 1974.
1974 1977
(4)
(4)
(5)
(2)
(4)
(4)
(2)
(D
(D
(4)
(D
(3)
(4)
(2)
284

-------
ABLEB-1 (continued)
HRUB8 (continued):
    A.
    B.
// Planted
     5
     5
     5
                                                                   Survival
                                                                 1974   1977
     Cornus stolonifera
     Ephedra viridis
     Penstemon strictus

5    Atriplex nuttalli
5    Ephedra viridis
5    Ephedra viridis
5    Arctostaphylos uva-ursi
5    Rosa woodsii
5    Eleagnus angustifolia
5    Eleagnus angustifolia
5    Penstemon strictus
5    Penstemon strictus
(1)     CD
(2)     (0)
(5)     (5)
                                                         (3)
                                                         (2)
                                                         (3)
                                                         (2)
                                                         (4)
                                                                  (5)
                                                                  (5)
       (0)
       (0)
       (0)
       (2)
       (5)
       (0)
       (0)
       (5)
       (5)
         Note:  Parts A and B planted in horizontal rows as listed.
         location map.
                                                             See
                                      285

-------
                                  TABLE B-2

            SOIL CONSERVATION SERVICE TEST HERBACEOUS  SEED PLANTING
                              PLOT DESCRIPTIONS '
                              SPRING 1973, 1974
PLOT NO.
HERB 1:
                   HERBACEOUS SEEDING RATE:   45  kg/hectare
                   WOOD FIBER MULCH RATE:   1,350 kg/hectare
                   16-20-0 FERTILIZER RATE:   560 kg/hectare
Northwest facing cut on Northstar Drive.  Spring 1973.
Subplots A through L left to right in 3.0 meter widths.

Singles                                                       	|

A.   Agropyron trichophorum (Luna pubescent wheatgrass)          100
B.   Agropyron intermedium (Tegmar intermediate wheatgrass)      100
C.   Agropyron smithii (Western wheatgrass)                     100
D.   Agropyron cristatum (Fairway crested wheatgrass)            100
E.   Poa ampla (Sherman big bluegrass)                          100
F.   Agrostis tenuis (Highland Colonial bent grass)              100
G.   Agropyron riparium (Sodar streambank wheatgrass)            100
H.   Festuca ovina duriuscula (Durar hard fescue)                100

Mixtures

I.   Sodar streambank wheatgrass                                 30
     Pomar Orchardgrass                                          30
     Durar hard fescue                                           30
     White Dutch clover                                          10

J.   Tegmar intermediate wheatgrass                              30
     Western wheatgrass                                          20
     Manchar smooth brome                                        20
     Sherman big bluegrass                                       20
     Rambler alfalfa                                             10

K.   Luna pubescent wheatgrass                                   30
     Fairway crested wheatgrass                                  20
     Sherman big bluegrass                                       20
     Latar orchardgrass                                          20
     Cicar Cicer milkvetch                                       10

L.   Fairway crested wheatgrass                                  20
     Pomar orchardgrass                                          20
     Sodar streambank wheatgrass                                 10
     Durar hard fescue                                           10
                                    286

-------
TABLE B-2 (continued)

HERB 1 (continued):
HERB 2:
 HERB 5:
          Mixtures
               Sherman big bluegrass
               Cicar Cicer milkvetch
               White Dutch clover
               Rambler alfalfa
                                                                          10
                                                                          10
                                                                          10
                                                                          10
          Note:  Each single or mixture type planted  in 3.0 meter wide plots
          left to right facing cut from road surface.

          South facing fill adjacent to Northstar Drive and West Martis Creek.
~~Spring 1973.

          Same single and mixture application  as listed for HERB 1, planted
          left to right facing fill slope from road surface.  Six meter blank
          spacing between single types E and F and mixture types I and J.

HERB 3:   Northeast facing cut adjacent to Big Springs Drive.   Spring 1973.
          Same single and mixture application as listed* for HERB  1, planted
          left to right facing cut slope form road surface. Mixture M was
          also included at right most end of HERB 3:
          M.   Purshia tridentata
               Atriplex canescens

HERB 4;   Southeast facing cut adjacent to Northstar Drive.   Spring 1973.
                                                                          50
                                                                          50
               Fairway crested wheatgrass
               Pomar orchardgrass
               Sodar streambank wheatgrass
               Durar hard fescue
               Sherman big bluegrass
               Cicar Cicer milkvetch
               White Dutch clover
               Rambler alfalfa

          Northwest facing fill adjacent to Northstar Drive.   Spring 1973.

          Same mixture application rate as listed for HERB 4.
                                                                           20
                                                                           20
                                                                           10
                                                                           10
                                                                           10
                                                                           10
                                                                           10
                                                                           10
                                     287

-------
 TABLE B-2  (continued)

 HERB 6;   East facing cut slope adjacent to parking lot near Big Springs
          Drive.  Spring 1973.
               Cana Reed canarygrass
               Luna pubescent wheatgrass
               Yellow sweetclover
               Cicar Cicer milkvetch
               Cascade broadleaf trefoil
                                                                           7
                                                                           /o
 30
 40
 10
 10
 10
HERB 7;   Northwest facing cut slope adjacent to'Northstar Drive.   Spring 1974
               Western wheatgrass
               Pomar orchardgrass
               Durar hard fescue
               Blando brome
               Lutana Cicer milkvetch
30
30
20
10
10
HERB 8;   Northwest facing cut slope adjacent to Northstar Drive.   Spring 1974
               Sodar streambank wheatgrass
               Pomar orchardgrass
               Durar hard fescue
               Blando brome
               Lutana Cicer milkvetch
               White Dutch clover
30
30
20
10
 5
 5
HERB 9;   Northwest facing cut slope adjacent  to  Northstar Drive.  Spring 1974.

          Same herbaceous seed mixture as used in HERE  8.

HERB 10;  Northwest facing cut slope adjacent  to  Northstar Drive.  Spring 1974.
               Luna pubescent wheatgrass
               Standard crested wheatgrass
               Blando bromegrass
               Sherman big bluegrass
               Palestine orchardgrass
               Lutana Cicer milkvetch
30
10
10
20
20
10
                                     288

-------
TABLE B-2 (continued)

HERB 11;  Northwest facing cut slope adjacent  to Northstar Drive. Spring 1974.
               Tegmar intermediate wheatgrass
               Western wheatgrass
               Manchar smooth brome
               Sherman big bluegrass
               Ranger alfalfa
                                                                30
                                                                20
                                                                20
                                                                20
                                                                10
HERB 12:
HERB 13:
Northeast facing fill slope adjacent to Big Springs  Drive. Spring
1974.

Same herbaceous seed mixture as used in HERB 10.

Northeast facing fill slope adjacent to Big Springs  Drive. Spring
1974.

Same herbaceous seed mixture as used in HERB 11.
                                     289

-------
,290

-------
z
o

'












o
B
-H
1<
•H
£
J
A
1}
a
X
1
£
CO
i

'ILIZER




O
[d
U
CO

Q
I
PM
U
d§
< M
p
< >-i
» j
0 IH
«a
• CO
pa



DESCRIPTIONS
E-i

<
M « 60
0)
1
n *J J
n O <0
3 5 "
O H
« o
CTv Vl <0
rH " Ht
CO
col^
X:! u 60
CO X
 C
^£3
O 33 CO
O
C.O
HI 6J!
00 O ~~-
CO
D.
r*— X
1-1 «
•H O.
vD O S^
CO H
33' MJ
in • (U
O pa
-* (U ft)
a PB
0 to
a ai
"13
z
•
i
1
I
XT*-., j
5{$ I

u td
i r-..
^b1

'



n
I8
N
*€
s




4J CO
U-) £
J-l
CN
3


















m
r*.
ON
d
3
i
<
z
c
M
H
U
U
CO

1
1
1

1
1
1
1
in
«— i
CM|CO
I
S*
o
in
U
Z
•-S
1
CMlCM
co|co
8 m
CM
in •
— < CO
1— <
o
CO
CM
O
CM
1
1
1
1
O
rs
M CO
or-
Ed in
o
o
(d •-!








r*-
r--
M
OS
CM
CO
1
Q
s
RESEE
r
I
1
1
1
1
1
1
1
1
In
o
o
CM
O
• o
CM CO
1
CJ 33
O
in
§
>-)
1
CM CM
H vD
CM vO
in r-
CM
VD O
CO NO
CO CM
*I

1
1
O
i-< O
1 r-
M CO
1
CO
O r-
CO
td r~








vD
r*.
8
M
g
c/a
P
cd
td
CO
Id
ai
i.
o
CO
CM
O
CM
vO
i-H
1
1
1
CM8
1 O
M CO
Q r-
[d in
i
w —i








r-
r-
g
t-H
8s
PM
CO
1
S
u
[d
:
o
o
*
I
0
o
•dj CM
^4 r-l
1
0
-H in
1 CM
t-t CO
1
Q in
Q ^
£ CO
o
00
o
• in
CO 
O CO
CM CM
m ON
CO
o
CO
CM
0
CM
VD
t— 1
1
1
1
O
CM O
1 0
H CO
Q r-
td m
o
o
W -i








r~
r*-
i
M
g
CO
1
Q
[d
Q
U
ta
CO
Cd
OS
=
vO O
CO CO
CO CM
O
CM
1
VO  — i
CM \O
in oo
in
VD O
0 CM
0
CM
1 «!
Si

1
1
o
—1 vO
1 CO
HI CO
1
0 ^
(d 0








vO
r^
g
M
g
CO
1
O
U
[d
CO
td
03
r
                              291

-------
 '$.
             §
8
                                                                        «! I
                                                                        T vo
                                                                        a-
OSS ml
-.  •  B »•
  o  -^
                 CM|O
                                                                       CM|O
                               292

-------


















•o
u
1
§
cj
• — '
CO
1
«
i
ILIZER
1



1
W
CO

a
CO
PL,
CJ
^M
CHANIC
ILIZAT
SS
«W



PTIONS
s
o
CO
8
H

 o
EH
HI K
00 0) v-'
CO
r-|
l-H tt)
•r4 0.
VO O >,
CO EH
... /-N
OS IM u co
in • u MJ S
p pa <• ^
» ^1 0
H < ^
a ^*^,
^•| J-S
-H O
z
§
CM
O
CM
2
•


0
CM O
1 0
M CO
P r-
[d in
o
o
W -H








r-
z
M
8?
P"4
1
§
CO
3
=
D vo
X) CO
N CO
O
CM
< 1
, 2

M
l-l O
H in
H
w o
CJ O
H in


Q sf

O
f-H
U
CO
$
1
OMo*\
CM|CM
EH
Bin
vo
CM CO
in si-
CO
i— i
•H CM
O
CM
i 1



O
~H CO
Ov
M si"

CM
O CM
O
vO
Q CM
1
1
3*
i
pa
Hi
D
CJ
o
f— 1
td
CO
B
i
e*4l -H

0
CO
M CO

O -*
O •*
1
1
0
• in
CO •*
o
sfloo
1
o
00
W
H 1
•-1 SB
in ^*
CO CO
CO CO
K m
CM 1—
in o
oo
)
•M
M
)
-H



O
CM 0
O
M CO
O r-
fd in
O
O
td -H









z
M
a
CO
1
s
Q
CO
s
:
O vD
30 CO
•M CO
O
CM
< 1
VO
4 I-H

H
-1 0
H in
H
U O
CJ O
H m


o -*
a 5
i
i
0
• o
vO vo
O
£
J
o
CO
u
a PM
in >~\
SIS
EH St
BS
m co
•-H rH
I-H

1
— (



O
CM O
Ql-
W *n
O
o









§
CO
8
td
as
-
293

-------


















a)
3
B
4J
O
CJ
ro

fi
i
ILIZER
5
u
ta



%
M
a
ta
CO

a
CO
CJ
d§
P
CJ M
!J"



z
o
M
CJ
CO
H
3
CK



<
ec
a) j:
CM -U ^
CM B t>
O
*H O.
OJ C(
M O E-
83
2£5
CO
CO t* ^
•-H 4J b
CO M
a)
r- o f
&• 'ft
2 **' *
m eo^
- BB
sfr 03 "-^
—1 M tH
O ^
CO (X
CM O
i M
-< U B
-1 a -r<
O 33 CO
-H . E
OvJ
0) f?
O Q) ^-^
CO
o.
i-l 0)
•1-1 a.
VO O >,
CO H
Si 




•U CO
1W g
< ^
5
5

S


























1
I
1
1
1
1
1
1
1
1
I
1
f".
D
CJ
3
ta
ta cu
-i i
^ as
COM
CMlcM
colco
H O
p ~*
co r*-
o o

o
CM
1
1

1
1
,
1
1
1
1
1
o
• in
O 
=3
CJ
1
Z
a
-t
i
CM CM
CO CO
H vo
3 CO
CJ ^
CM CM
in CM

CO
CM
O vO
CO CO
CM CO
O
CM
< 1
is
1
M
H O
H in
ta o
CJ O
33
i
i
0 sf
CO
a in
1
i
1
1
§
,
Si
ta
H
1
CM CM
CO CO
H vo
82
CM CM
>n cs

3
1
1
1
1
1
1
1
1
1
•A
1
,
1
=> CO
CJ -^ •
1
ta
z
a
i
CM CM
CO CO
H 1 —
3 vo
CJ ~H
CM O
in •—•*

in
CM
VO O
CO vO
CO CM
O
II
1
1
1
O
~H VO
1 CO
M CO
1 1
in
a •*
in
ta •*








vo
-i
•A
14
1
ta
ta


294

-------


















•a
I
|
CO
i

M
1-5
H
ai
H
Id



o
Id
Id
03

Q
03
CJ

a"s
3 H
B.l



03
S
S
M
ttl
CJ
03
I

^
ig 60
as 4
03 •-
Q a
60 U -—
rH 4J 60
O3 &4
0) f
i~ o ja e
-1 5 -H^
3 faE-
X,
s.s'%
— 1 0> M
iJ M
• a
 **
co 
d in
o
o








_£
»
B
Q
Id .
03
Id
OS
-
D VO
» CO
N CO
0
CM
i— (

O
O
< CM
> i— 4

O
CO
M CO

r-
43 -*

--4

d O
0 0
03 i-l
H
* O
: co

Or-
d in
o
o
Id -H








?
M
PH
i
Id
03
U
CIS

O CO
CM CO
O
CM
< 1

O
O

D
•M
3
-H

O
65 O
03 O
O3 ~H
H
< O
Id m
c CM
s co
1
e i-
d m
0
o
65 -4








1 —
r-.
i
CO
1
Q
S
1
=








,
i
,
i
i
a
3
CJ
1
63
O3
a
i
CMlCM
CO|CO
8O
I-.
CM \D
O
CO
^
1
—I



O
f-4 \O
CO
4-4 CO

O
O
O -H
§
W ^H








VO
M
a
CO
1
1
w
CO
=
295

-------


















•a
CJ
1
JJ
1
CO
J
•ILIZER
ta



o
u
CO

a
CO,
cu
o
^
p




CO
1
H
o
CO
%
H

^
»
CO H
m • o> iw B
0 « < v^
60MH U
-^- o) a> tw
Q M <
o) a ^
O, CD CM
" tH^-JjO
•
M|33
•H O
Z:
o
CO
CM
O
CM
1
vO
1
U
Cd 0
CO O
CO *H
So
w m
E CM
,
O r-
U m
o
o
W 'H








S
1
a!
a<
CO
1
a
H
CO
U
.
VD 
t-H
vo

0
00
CM
o
CM
1
vO
1
M 0
H O
So
Ed O
5 m
1
Q r-
ta m
o
o
ta -H








£
S
CO
1
1
Cd
Ed
CO
s
_
oo cn
CM cn
0
ii


,
in
CM r-
1 •*
IH CO
1
Q -*
r-*
O in
,
I
1
1
m
a
8
1
C/3
g
i
CMlcM
CO|CO
b co
o a.
CM — 1
in vo
CO
CO
0
00
CM
o
CM
1
1
M
M 0
EH O
H -i
So
u o
g in
1
O r-
td in
o
o
Cd -H








£
g
M
ad
CM
CO
1
a
Ed
a
Cd
[O
Ed
_
00 CO
CM CO
O
-a?
±s
i
M
W O
EH in
u o
u o
33
i
i
o -*
r—
a in
i
i
i
i
ta
g
CJ
i
S
n
,
CM CM
CO CO
U CO
CM in
in in
i-H
CO
o
00
CM
O
CM
1
vO
r-H
1
O
EB< [in
Cd O
S ""*
i
0 1-
Cd m
o
o
Cd -H








?
CD
CO
1
Q
Cd
Ed
OS
_
1
1
1
1
1
1
1
1
1
1
1
1
1
3
i
Cd
CO
Cd
H
1
CMlcM
co|co
BZ
CM CM
in in
R
0
oo
CM
O
CM
1
1
O
tci in
IX oo
< o
td O
gin
•*
,
O !>•
cd m
o
o
Cd •-<








£.
i
CO
1
1
u
Ed
CO
Cd
K

296

-------


















0)
g
• H
4J
B
O
o
CO
i
w
i
'ILIZER
b.
fci



a
Id
CO

a
CO
o'
^
g3
< M
0 M
H



1
M
EH
0
1

<<>
a
oi .e
CS 4J --.
CS OJ 60
01
>-< a
r4 4J 4J
01 W C
o js o) a)
CS 4J U B
0 H
MOO.
<* rJ B !>,
^SH^
n »
00 rJ 	
— < 4J 60
CO M
%
-iS
in 60~~-
— 1 41 60
M- so
— < h 60
CD W
01
CO O.
CS O
-i SS
4-1 boca
-H 4-1 0 S
— i « -H O
s *>g«
crv o
OO 03 *~s
CO
"~- (§"
rH 01
•H O.
VO O >.
CO H
W M-IJ4J
in • 0) 14-1
o pal. h a
H < ^
N-|33
— 1 O



«

1.
!




S





5




o in
o\ cs
CS CO
o
cs

-------



















•a
3
C
g
U
to
1
pa
S
3
CILIZER
(X
Id



8
M
g
Cd
W

Q
i
a.
o
3§
p
U M
P




o
M
S
u
CO
td
a
1


^
a
U J=
CM 4-1 ^^
CM O 60
0)
-H Q.
IH 4->
cu a
0X0)
8-g
O\ 1-4 4
•-I u E-i
en
— « iJ M
en M
0)
^•SJs
-Sfi
• a
2I^
in ti"-.
-H tu 60
• SB
•3- 0 —
—< H 60
U US
0)
CO O.
S,g
jj £(j
-H 4J C
-H a -i-i
o SB' co"
CTv O
E-i
vU X
CO 91 v^
CO
O.
1- X
td
rH Cl
•i-l CU
VO 0 t*.

in • cu
o pa
60 HH
> V4
H •<
.
"13
~°


U
C
§
U 63

/-s
ID te
0*p*.





&
>





£"5
4j
S

•S.

in o
oo m
CM CO
0
CM
"f ''
S -<
1
o

in
I
r-
O *
1 CM
M CM
1
O
O m
0S
1 •
1
1
1
1
CJ
i
td
g

1
vO vO
CM CM
Bco
O r-
CM »-H
in vo
5
o
o\
-* 1
o
CM
1
VO
— 1 1
1
1
1
O
1 CM
I-l CM
1
CO
Q r-^
CO
O r-
1
1
1
1
o
1
*
B'

,
VOlvo
CM|CM
E-l
F? S
\J ON
CM i-t
m vo
5
0
0\
•* 1
o
CM
1
vo
<-l 1
1
1
1
i-l O
1 •*
M CM
H CM
|
O
O
O -<
o
o
Q -I
1
1
1
,
I
1
Id
S

1
vO vo
CM csl
B CO
O Ov
CM •-!
in vo
t— 1
vO
o
-* 1
o
CM
1
vo
—I 1
1
1
1
O
— 1 O
1 r-
M CO
1 1
o
«S
o
02
i
i
i
i
i
,
*=
td
EH

1
vO vo
CM CM
p CO
Q OV
CM ~H
in vo
•— i
r-.
in
CM 1
o
CM
1
vO
1
r
i
o
>-I CM
1 1
O
Q m
o
Q in
1
1
1
1
1
1
td
B

i
VOlvo
CMJCM
Is
CM -H
in vo
i— i
00
o
00
CM |
O
CM
1
vO
i-l 1
1
1
1
in
-H CO
1 O
I-H -*
1 1
O
O
eS
i
i
i
i
1
i
Id
Id


VOlvo
CM|CM
O vo
o in
CM r-
in co
r-H
3
298

-------


















tinuec
o
o
i
03
1

ILIZER
N
b
W



Q
U
CO

o
w
H
Pu
0
*s
i~
O M
!JS


PTIONS
«
O
CO
g
1

<

Q
-.
^H O -H >-,«>
» toffjg
• Z3
10 to ^.
"l J= M
CO M
• 35
in oo<.
^3^
^»5
i-H ^ M
0 M
(U
f> &
'H >,
H
CM O
-i Z
1 ^
•u bou
—i -u a s
-, « .H o a
*~s
2 « i^
o --^
CJ
o\ o
H
eu^x
0) X
00 0) ^
CO
o.
r~ X
H
1-4 (U
•H CL.
•a o >>
to H
S3 IH U CO
in • a) in g
O » «« -^
OO "4-1 U
-* a v <*-i
n « <
0} CO x-^
a. , M B
EH < ^
CM-H J J
— i O
z


















in
p^
o\
1
i->
g
M
CQ

0
GO
CM 1
0
CM
1
>O
-H 1
1
1
w o
o o
HI m
«l -3
<^
Z
in in
CM CM
1 1
O 0
jj O
i-J r-
H O
x^ ^
<
>-)
299

-------

50
SCALE (meters)
 "1       I-
  100     150    200
                 STATE  OF  CALIFORNIA
           STATE WATER RESOURCES CONTROL BOARD
          HERBACEOUS SEEDING AND WOODY
                PLANTINGS,  FALL,  1976
              AT  RUBICON PROPERTIES
          DEMONSTRATION OF EROSION AND
           SEDIMENT CONTROL TECHNOLOGY
                               FIQUR E , NUMiER
                                  B-3
     300

-------









vO
rt
,J
Q


J-l
H
O4
1— 1
02
1
H
CO
Id
H-t
S
[I]
Ou
o

a
§
^.
I
PQ

3
i
CILIZER
a



M
Q
W
ia
CO

a
CO
CJ
3S
U M
m



PTIONS


1



<
0> fl
CM 4J -»
CM at bo
04 r^t
HI
rt O.
hi
o a> a
a o
ON U «
CO
00^
i-H 4J 00
CO «
a
13 1*
T^ O &
-" £ y-i
S fe!
VO C^
CO M
rt **^
rH ^1 00
O NS
u
co O.
rt >,
CM 0
1
rt t! c?
rt « -H
O Bfi CO
"o S
o
CTv O
J-i
CL^~^
CO
a
rt 11)
•rJ 0.
vO O >,
CO H
•C m
m • cj
O PQ
oo VH
>rh CO fl)

a) (H
o- 
82
CM «— «
in 0*1
~*
•— i
=
=
i
i
CO
M O
> O
«sj m
Q st
1
CM
CJ 0
CJ CM
VO
CJ CO
1
(
O
CM|CO
VO|S
=
1
=
Sg
i— i
in -<

H 0
8O
CM
CM -H
in co

CM
:
=

1

1
s
-
_
1
1
o
VO,*
=
1
r
=
rt in
313

H 00
CM cn
m -3-

 O
S3
1
CM
CJ 0
t— t
CJ CM
CJ CO
1
1
in
• CO
rt CM
VD
;
1
Z
:
0|CM
in o

-------
      S .KOJJ
                                                         §
                                                                    •< 00
   p SB
                                                                    co [in
ig
> ra

     H <>-'
        B H
                                       302

-------




















w
c:
^
«
W
£
'ILIZER
1



i
M
O
Id
d
to

a
i
o
d§
-2 M
gel
^3 M
PC --J
O H
Sg
• CO
m



M
CM
g
00
0
EH
s
CU


•<
CO
0) J3
CM i-l --.
CM C8 60
0)
-H O,
CM >,
H
lit
o^ §T
CM u ^
0 EH
S ^
CO U
ON IJ CO
-H u HE
to
CO V^ — .
^H 4J 60
to $6
* 2
r~ o ja
-H .C 60
to u:
in 60-*-.
^H 01 60
• *
-3- 01 -^
— 1 ,J 60
O $6
a
CO O,
CM O
-H g5
1
JJ CO
-H CO -H
0 BJ co
~o- 8
ON§
a) **
OO 01 v-'
CO
a.
r- X
U
r-l 0)
•H a
to O >N
to H
A MH
in • 01

60 U-l

ai co
a. ai

NS3
—i O
Si
1

1 !
*£ 1
?»
*_-•

^~\
t> t£
•—^





Ls
u




£<^

I4J
S

CN

J


























o
CO
CM
O
CM
1
tO
1
1
1
1 O
Sg
t-H CM
CM
< CM
CM
«5
E
g
O
in
VD
CM
CM 00
i-H i-H
1 1
=
1
-
O
CO

'
CM O
•* -*
EH ON
8-3-
CO
CM ON
in CM
-H CM
T-H
CM


1
1
1
1 O
r-l O
M 00
M CM
m
in
— 1
CM
CM


1
1
1
-H O
1 O
t-l CO
H CM
CM
•4! CM
<2
 0
<£ in
3 **
,
r-4
0 C3
r-H
CJ -H
CO
1
1
,
o
E
1
=
z
0

00 •*
"*
p co
CM --H
in o\
in
C4


1
CM
X in
8£
to
M O
> O
 0

-------


















M
S
o
**•
ta
w
H
'ILIZER
fe
IK
w



g
M
o
CO

Q
U}
CM
O
3p
~-4
1"
Iri
yg
«•"



55
s
H
P-.
1
Id
Q
H
S
CL,


•<
(0
a) j3
CM u •*»
CM eg 60
« X
0
««
CO 0) ^>
CO
o.
r^ X
ta
i-l U
•H D.
VD O t>>
CO H
as i«|u|pr
in • ojlu-t 3
o pa|>!-; B
t->  o

IN —<
in vo
CM
CO
_
:
1
1
I
-
-
s
^
I
1
1
1
r
1
-
-
1
0 3- co
H
S vo
O -*
VO -H
r — vo
CO
CO
„
=
1
1
1
_
_
_
„
CO
S —
Q
CO
0---
in
t— i
1
1
1
1
-
=
1
m m
CO CO
dcM
M en
fa CJ
c^ c^
u~i iri

M 10
m
< -*
m

co|co
d^
E§
cs 
-------


















1
M
1
*»•
PO
sj
ILIZER
a
i.
W



a
M
n
H
CO

Q
i
PL,
0
32
O M
• CO
PO



PTIONS
CO
Q
H
3


^
CO
a> j:
CM 4J -->
CM CO 60
04 ^
— 1 O.
1
V-i 4-1 J
o) n
CO U
ON tJ C8
-< 4J HE
CO
CO SO
2JJ-3,
CO M
(U
•O h
f~ O .0.
vo n'5
-iS
-J!
CO O.
CM 0
1
AJ bo
—< u C
"* 0 2
01
ON O
CO V "*-^
CO
"" w
r-( 01
•H O.
\f> O >,
CO EH
ac 
o pa
OOU-I
-» O CD
o pa
o 
a
i
<
<
<
i
i
i
CO
-
1
-
B
CM
in

g
CM
2
3


r~
r-*
o
in
o
o
-*

CM
CM
2
3



vO
vO




n
o in
S i->
_
i
;
J
-
O
0
in
1
vO
00|vO
pa oo
i
B
=
CM
O vo

8 S
CM ^H
in vo
-a-
_
E
^-> 0
gl|CO
CM
S in
Sin
r-
s
1
=
r
-
CO
g
o
in
1
O CO
-H OO
r
i
-
.
CM
r-t CM
m oo

gco
O CT\
CM ^H
m vo
00

-------









•









*~»
Q
S
t.
EH
1
*f
«
i
ILIZER
1
u.
ta



g
M
Q
H
CO

Q
1
o •
3Z
1-
CJ W
«•"



CO
yz
s
X
t-4
cd
8
ft
EH
3
CM


<
a
 a>

cj) a
o. u
.
N|3
-H O
z


4J
B,
£.£•
^
i
P^T^
S-R
t
I



CO
§B
•N
^






il
-H
CM r-
m o
r-H t-H
CO
in
„
=
1
I
1
-
in
in
< CM
< 00
1
I
1
CO
<3 oo
CJ -"
1
-
^

r~|-*
olo

EH vo
vj •— i
CM VO
in r*-
m
_
r
1
1
1
CO
1 0
I-H O
M VO
M in
in
in

-------

TABLE B-4 (CONTINUED)
E. FERTILIZER
a
a
a
CO
n
CO
H
o
e
-i <
3 *~^
• CO
w



>
-i
H
O
a
H
i
i*

«i
a
CM 4J *^
CM co bo
01

1
t-t JJ JJ
_ 0 co C
2 J3 si oj
CM 4J >v H
O EH
ft X O 1C
co o o.pL
a\ ij co >, oo
-H 4J HH te
CO ^
00 K --.
l-H 4-1 00
CO Mi
»]£p
-H J3 M
CO Nd
in o<>51
2 STS
O M
HI
CO 0.
3*
4J 0001 1
-HUB*
-1 «i -H 0 IB
0 93 CO 1
1-1 o 5J**
0\ O
H
0) M
CO 0) ^-
CO
-1
i-H <1>
•H (X
*o o >•»
CO H
^35tSi
o n
•U CO
00 MH 1 U
* O HI OH
O, DCS
N|33
-H O
Z

o
00
CM
O
CM
1
v£>
1
1
1
7 o
M CO
l-H CM
in
in
•< CM
CO
< 00
1
r







volvO
co|co
1
CO
1 i—t
I >£>

.
=


1
1 O
-i in
:


1








1 CO
CO
i-H
VO

;
=
1

1
CO
t-H 00
I-H CM
CM

m ^a-
1
CM
 O
1
in
< CM
. CO
< CO
I


o

m
3 co

e

-10
COICM
ro|co
t-H
J t— 1
VI to
n r-


=
6K
o
CO
H 0
H m
o
CJ O
S m
£ -*
I
CM

-------
( !


















f
i



\ S
*4 *~
f


8
HI 1
3 r
M
CO

o
3
14
O
z
p
3 5
0 M
pa



CO
1
-s B
2 o:
d O
2%
2*
33
=>•
«
IL
HI 43
J 4J 	
J to OO
K .***
OJ
-1 O.
"£•
U 4J4J
a) to a
3 J3 ,
-l 4J E-iH
CO ^-
3
-H 4-1 OO
CO SA
•O H 01
— O JO O.
-1 O -H >-
S PwH
CO M
m ei-~.
— a) oo
• S3
— M 60
C3 btf

H **o
8-
in r^.
R
_
=
•^
•
Jin E
3iC I
n
-< o
> o
S3

—
u o
I— 1
o —
CO
1
1
1
o

pa crv
o o
i
z
o
-10
O 00
•* CO
H
ID c*i
o cy»
CS -H
n
_
=
N O *-
-< CO P
c cs £
si
c m







i
0
o

=

.
B
CM|O
CM 00

-------
TABLE B-4 (CONTINUED) ' . '
m
>J
1-1
H
[n
M
a
la
CO
CJ •
2 3
'J M
SCRIPTIONS
a
I
.
03
C«J Q) 43
cs -u •*•*.
«.*
(!)
-H (X
»j L.ti
o co « e
O H 	
« o O.-K
t-H JJ HE-i £e*
CO v^
00 tJ -~
—1 4J UO
CO te

CO >, H
AJ en
5 3
<4-l
£>
3 i-H
O -H

in r-
CN
00
^
=
1
t— 1
S in
Sin
r^
CO
i-l O
> 0
Q 3
1
CN
CJ 0
CJ CM
CJ 00
1
1
1
1
B
1
=
~
1


J rt

in r-
CO
00
_
=
—* o
b CO
$ CN
CN
3 m
S i—

1
s
..
_
I
1
1
1
B
i
B
-
1


J ~

in r~
oo
^
=
^ 0
CO
H m
gs

1
-
.
_
1
1
1
1
.
1
:
I


H ON
D CO
0 -H
in m
m
00
_
=
1
1
1
CO
1 0
1-1 O
1-1 M3
M in
in
< 
OO

SEE TABLE B-VI
SECTION J
_
i
W
i
m|
-------











*






1
I
«j.
A
w
5
ILIZER
t
a
W



g
-i
a
cn

Q
cn
H
CJ
4§
S H
U H
P



i
EH
PU
OS
U
cn
1


^
a
a x:
CM -U ~-
CM a 60
p£ .a
u
-•H CU
wi,
: <
s u
a\ P a
.-< u HE
w •
S
a 5B
oo to "**~
i-H JJ 60
co ! O

-------

TABLE B-4 (CONTINUED)
|E. FERTILIZER
\s
-4
n
W
CO
o
CO
-4
PH
CJ
^
sa
2 H
J H
«'»


CO
-4
H
O
a
3
3

<<
QJ .C
CM 4J "^
CM (U W>
r-l O,
h 4J U
0 Js 88
O H
n o O.-K
ON n *IM
CO **•
CO H —
-HUM
CO S4
T3 ^ I) tt
S f^t E-< M
vO M "•••.
m W)-^
-H h M
O M
CJ
CM O
1 /-^
•u bfico
-HUGS
-< B -rt 0 S
• x-x
0 SB CO 1
CJ
ON 0
CJ »<
CO
u
1-1 a
•l-l OH
vo o :*
CO E-l
in • a)
o «
MM-I
Jt 01  0

— 1
_
=

i
i
o
o
vo
M in
 O
•MNO
n 
-------
312

-------
                                  TABLE B-5
                          PLOT DESCRIPTION SYMBOLS
 Note:
This table identifies the meaning of those symbols used to  describe
the plots in columns 1 through 23 of Table B-3 (Northstar Plot
Descriptions) and Table B-4 (Rubicon Properties Plot  Descriptions).
A.   PLOT DESCRIPTIONS
 Column 1.
  Plot Identification Number.   Corresponds  to number  in Figure B-3
  and Figure B-4.
 Column 2.   Plot Dimensions

            Top - Width, meters
            Bottom - Slope length, meters

 Column 3.   Plot Type and Area

            Top, cut or fill
            Bottom, area, square meters

 Column 4.   Plot Slope Angle

            Top - Angle of slope before implementation of  erosion control,
              degrees
            Bottom - Angle of slope after erosion control  measures, degrees.

 "olumn 5.   Plot Overhang Description

            For the purposes of this table,  "Overhang" means all material
            above an imaginary 45 degree plane  transecting the steepest
            uppermost portion of the cuts.
                                                    o
            Top - Amount of soil in overhang, metersj  before erosion control
              implemented
            Bottom - Estimated amount of soil remaining in overhang after
              erosion control implemented.

Column 6.   Plot Soil Type (Soil Conservation Service  Classification)

            MsG - Meeks  very stony  loamy coarse sand,  30 - 60% slope
            DG  - Decomposing granite
            JTF - Jorge  - Tahoma Association, 30 - 50% slopes
            H-P - Hardpan layers producing seepage areas

            If more than one type is  listed, the first is  the more prevalent
            type.
                                     313

-------
TABLE B-5 (continued)
Column 7.   Plot Exposure.   The directional exposure of  the plot face. N
            denotes north,  E denotes east,  S denotes south, and W denotes
            west.

Column 8.   Plot Seepage.   The percentage of the slope that is affected by
            seepage during late spring and early summer.
B.   MECHANICAL STABILIZATION
Column 9.   Slope Toe Stabilization.

            Top-type of toe stabilization.

               ROCK - Rockwall of .5 to 1.5 meter diameter boulders
               GAB  - Rockfilled wire mesh gabion baskets
               CURB - Roll curb and gutter

            Note:  Gutters were constructed at foot of all rockwalls and
            gabions.  No toe stabilization on fill slopes.

            Bottom - height of stabilizing structure

Column 10.  Slope Overhang Stabilization.
                                                         o
            Top - amount of soil removed from overhang (m )
            Bottom - percent of total overhang removed.

Column 11.  Willow Wattling.

            Top - Number of rows of wattling
            Bottom - Total length of wattling in meters.

C.   PLANTS
 Column 12.  Number of Each Type of Plant

 Column 13.  Transplant Type

            GRS  - Container grown grass seedlings
            SHRB - Container grown shrubs.  Unless otherwise indicated,  all
                   shrubs were obtained from the Dept. of Env. Horticulture,
                   U. C. Davis.
             (HO) - Plants obtained locally
            TRS  - Bare root trees purchased from the California State
                   Division of Forestry.
                                      314

-------
TABLE B-5 (continued)
D.   PLOT SEEDING
Column 14.   Grass Seeding Hate, kg/ha.

Column 15.   Legume Seeding Rate, kg/ha.

Column 16.   Shrub Seeding Rate, kg/ha.

Letters A-E in Columns 15-17 indicate seed mixtures  as  follows.  The top one-
quarter of all plots at Rubicon Properties was  hand  seeded with grass mixture
 C  at a rate of approximately 50 kg/ha after application of final mulch or
           PERCENTAGE COMPOSITION OF  SEED AND FERTILIZER MIXTURES
                  USED AT  THE  EROSION CONTROL PROJECT SITES
     GRASSES

     Luna pubescent wheatgrass
     Tegmar intermediate wheatgrass
     Durar hard fescue
     Potomac orchard grass
     Manchar smooth brome
     Lincoln smooth brome
    LEGUMES

    Lutana cicer milkvetch
    Dutch white clover
    Cascade trefoil
  Grass  Seed Mixtures
  A   B    C    D    E
11
66
17
11
56
—
33
16
42
16
16
40
40
—
20
                    25
                    25
                    12
                    25
                                                —   —   10   —   13

                                               100  100  100  100  100
 Legume Seed Mixtures
 ABC    D    E
57   50   67
24   50   11
19   —   22
50
50  100
                                               100   100   100   100  100
                                    315

-------
TABLE B-5 (continued)
     SHRUBS AMD WILDFLOWERS

     Artemisia tridentata
     Purshia tridentata
     Oenotheria hookeri
     Linum lewis ii
     Gilia leptantha
     Nemophila maculata
     Eschcholzia calif.
     Eriogonum umbellatum
                                                  Shrub Seed Mixtures
                                                  A    B    C    D
10  100  100
30   —   —
20   --   --
10
10   —
10
10   —   ~
10
10
30
60
                                                100  100  100  100

Column 17.   Wood Fiber Mulch.

             Top - Type of mulch and method of seed application.

               I - Weyerhauser "Silva-Fiber"R
              II - Conwed Hydro MulchR
             III - Conwed Hydro Mulch "2000"R
               1 - Seed in mulch
               2 - Hydroseeded, then mulched
               3 - Hand seeded and raked in, then mulched

             Bottom - Rate of mulch application, kg/ha

 Column  18.   Straw Mulch.

             Top - Type of straw applied

                   DAVIS - Barley straw
                   PMC   - Tall wheatgrass
                   BOTH  - PMC in upper part of plot.  DAVIS in lower part,
                   RICE  - Rice straw
                   WHEAT - Wheat straw

             Note:   Seed hand cast and hand raked  on all straw plots.

             Bottom  -  Rate of straw  application, kg/ha

 Column 19.    Straw Tack.

              Top - Type of straw tack applied

                    SSEC     - Sta-Soil Ecology Control
                   TT II    - Terra  Tack IIR
                   TTSC     - Terra  Tack IIR,  super concentrate
                                      316

-------
TABLE B-5 (continued)

Column 19.  (continued)
                   WF       - Woodfiber
                   PVA      - Polyvinyl acetate (used to tack wood fiber
                              mulch only)
                   DOW      - DOW Chemical USA XFS - 4163 L mulch binder
                   (1,2,3,X)  applied as indicated below:
            DOW MULCH BINDER APPLICATION RATES
            DOW 1
            DOW 2
            DOW 3
            DOW X

            Note:
       Water
       kg/ha

        4.25
        4.25
        4.25
        8.50
Latex
kg/ha

  .77
  .77
  .77
 1.54
Modifier
 kg/ha

10.2
10.2
10.2
20.4
                                                                Wood Fiber
                                                                  kg/ha
230
460
460
DOW XFS - 4163 L mulch binder is a form of Styreme
butadiene (SBR).
            Bottom - Straw tack application rate,  kg/ha

Column 20.  Other Materials Used to Stabilize Seeded  Slopes

            EXCEL  - ExcelsiorR netting
            CONWED - ConwedR plastic netting
            HG •    - Hold-GroR netting
            JUTE   - Jute netting


E.   FERTILIZER
Column 21.   Type of Fertilizer Applied.

            16-20—0 - Commercial fertilizer
            M-A     - Mag-Amp  7-40-6  slow release
            U-F     - Urea formaldehyde  38-0-0  slow release

Column 22.   Rate of Fertilizer Application, kg/ha
                                     317

-------
                          LEGEND

                           PROJECT SITE

                           SHRUB a TREE
                     • f   PLANTING SECTIONS
                           SPRING,  1977.
                                STATE  OF  CALIFORNIA

                          STATE WATER RESOURCES CONTROL BOARD
SHRUB  AND  TREE PLANTINGS

        SPRING, 1977

   AT RUBICON  PROPERTIES
SCALE (METERS)
  i	1	1	1

 100  150 200 250 300
                   318

-------
                                 TABLE B-6

                  RUBICON PROPERTIES SHRUB PLANTING SECTION
                        DESCRIPTION - MAY, JUNE 1977
Section A:
Section B;
Section C:
Section D:
Section E:
 East facing cut slope adjacent to Rubicon Glen Drive.  Planted
 6/3/77.
                                               &
 160 Atriplex canescens
 160 Ceanothus prostratus
 120 Rhamnus rubra
 120 Penstemom strictus

 Note:  Spacing is variable.  Planted as listed above right
 to left facing slope from road surface.  Propagated in various
 containers.  Fertilized with various fertilizer treatments.

 North and west facing cut slope adjacent to Rubicon Glen Drive.
 2-3 rows of wattling at south end of section.  Planted 6/23/77.

 600 +_ willow stakes driven in at random over entire plot.

 East and west facing cut slopes adjacent to Rubicon Glen Drive.
 Planted 6/3/77.

 350 Abies concolor, Abies magnifica, Pinus jeffreyi (bare root)
     various pines and firs (bare root)
 280 Penstemon newberryi
  50 Erigonum umbellatum
 440 Agropyron trichophorum "Luna" (peat pots)
  80 Atriplex canescens

 Note:  Above planted at random within Section C.

 East to north facing cut slope adjacent to Rubicon Glen Drive
 and Lonely Gulch Creek.  Planted 5/24/77 and 6/3/77.

 120 Agropyron trichophorum "Luna" (peat pots)
  80 Penstemon newberryi
 160 Chrysothanmus nauseousus
+300 Willow stakes

 Note:  Above planted at random within Section D.

 Northwest facing cut slope adjacent to Rubicon Glen Drive and
 Lonely Gulch Creek.  One and two tier gabion breastwall con-
 structed behind curb and gutter at slope toe.  Slope scaled,
 overhangs removed with three to four rows of willow wattling.
 Planted 6/2/77.
                                      319

-------
TABLE B-6 (continued)
Section E (continued):
Section F:
Section G:
 Section H:
100 Pinus jeffreyi
280 Agropyron trichophorum "Luna" (peat pots and books)

Note:  Jeffrey pines planted in fertilizer test plots.

Abandoned dirt road adjacent to Lonely Gulch Creek.   Planted
5/11, 12, 13, 24/77.

500 Pinus jeffreyi (bare root)
275 Pinus lambertiana (bare root)
120 Purshia tridentata (books)
120 Ceanothus prostratus (books)
120 Chrysothamnus nauseosus (peat pots)
 20 Cornus stolonifera (deep tubes)
 40 Penstemon strictus (peat pots)
 40 jlymphoricarpos sp. (peat pots)
 40 Prunus emarginata (peat pots)
 20 Penstemon newberryi (deep tubes)

Above planted in fertilizer test plots and container compari-
son plots.

160 Agropyron trichophorum "Luna" (peat pots)
213 Penstemon newberryi
603 Prunus emarginata
 55 Penstemon strictus
 60 Atriplex canescens
 40 Lupinus sp.
 60 Rhamnus rubra
 90 Ribes sp.
 68 Ceanothus prostratus
 16 Cornus stolohifera
 15 Eriogonum umbellatum
 48 Salix sp.

Planted  in blocks by species.

Severe north facing cut slope adjacent to Lower Lakeview Drive
Two and  three tier gabion retaining wall constructed behind
curb and gutter at  slope toe.   Slope  extensively scaled and
overhangs removed with four to  six rows of  contour willow
wattling.  Planted  6/3/77.

  66 various Lupinus species
400 Agropyron trichophorum "Luna"  (peat pots)
  80 Penstemon newberryi
                                      320

-------
 TABLE B-6 (continued)
 Section H (continued):
 Section I
               Note:  Lupinus species planted with various fertilizer treat-
               ments.  Other plants at random.  Partially replanted on 6/20
               with +200 "Luna" and Penstemon newberryi.

               Cleared lot above Section H adjacent to North Lakeview Drive.
               Planted 5/24/77.

               120 Agropyron trichophorum "Luna" (peat pots)
               240 Atriplex canescens (book planters)
               150 Abies concolor (bare root)

Note:  "Luna" and Atriplex planted in fertilizer test  plots.

Section J:      Severe east facing cut slope at corner  of  Lakeview and Manzanit
               Drives.   Two and  three tier gabion retaining wall constructed
               behind curb and gutter at slope toe on  southerly two-thirds of
               this section.  Planted 6/1,  3/77.

               140 Eriogonum umbellatum
               100 Pinus labertiana.  and Pinus  jeffreyi  (bare root)
                80 Atriplex canescens
                40 Chrysothamnus  nauseousus

               Note:  Erigonum on northerly  15 meters of  section with various
               fertilizer  treatments.

               East facing  cut slope  adjacent  to Upper Lakeview Drive.
               Planted 5/24/77.

               250 Penstemon  newberryi  (small tubes north end)
               280 Agropyron  trichophorum "Luna"  (south end)

               North  facing cut slope adjacent to Forest Drive.  Four rows of
               contour willow wattling.  Entire slope extensively scaled with
               overhang  removed.   Curb and gutter reconstructed at slope toe.

               390  Penstemon newberryi
               280 Agropyron  trichophorum "Luna"
               240  Chrysothamnus  nauseousus
               75 various Abies  species
               400 willow (Salix) stakes
               200 Atriplex canescens

              Note:  Above planted in fertilizer and container test plots.
Section K:
Section L:
                                     321

-------
TABLE B-6 (continued)

Section M:
 Section N:
 Section 0:
 Section P:
North facing cut slope at the end of Forest Drive.   Overhang
removed and 3-4 rows of contour wattling placed at  2 meter
intervals.

 80 Penstemon newberryi
 52 Chrysothamnus nauseosus
 42 Purnus emarginata
123 Atriplex canescens
 67 Ceanothus prostratus
 10 Symphoricarpos sp.
 60 Purshia tridentata
 21 Rhamnus rubra
 22 Arctostaphylos patula

Plants listed above planted at random below wattled cut and on
adjacent cuts.

250 Penstemon newberryi
160 Ceanothus prostratus
280 Purshia tridentata
180 Chrysothamnus nauseosus

Plants listed above planted in fertilizer test plots on wat-
tled  cut.

Abandoned dirt  road from Highland Drive.  Water bar and grass
seeding  conducted in  fall  1976.  Planted 6/1/77.

400 Agropyron trichophorum "Luna"

Note: "Luna" in peat pots placed southerly portion adjacent to
       Highland Drive.

Northwest facing fill slope  adjacent to Highland Drive.  Plante
 6/1/77.

 250 Pinus lambertiana and  P.  jeffreyi  (bare root)

 Northwest facing cut  slope adjacent to  Highland Drive.  Four
 rows  of  willow  wattling on southerly portion.   Planted 5/27/77.

 360 Agropyron trichophorum "Luna"  (book planters)
 125 Pinus jeffreyi (bare root)
 125 Pinus lambertiana (bare  root)

 Note:  "Luna" on northerly portion of  section and  Pinus spp
 planted in fertilizer test plots.
                                       322

-------
TABLE B-6 (continued)

Section Q:
Section R:
East and west facing cut slopes adjacent to dirt road leading
to water storage tank from Highland Drive.   Planted 6/1/77.

250 Pinus lambertiana and P.  jeffreyi (bare root)

North facing gentle slope with a portion of cut and a portion
of an old road.  Planted 6/15/77.

240 Prunus emarginata
280 Purshia tridentata
160 Ceanothus prostratus

These planted in fertilizer test plots.

Area adjacent to test plots planted with +_ 400 container grown
grasses and shrubs.
                                     323

-------
Number
                    APPENDIX C

WATER QUALITY AND ENVIRONMENTAL MONITORING DATA




                     TABLES
 C-l      Water Stored as  Snow for each 105 Meter  (500 Feet)
          Contour Internal at Northstar  ..............   328

 G-2      Suspended Sediment Sampling  Site Locations in West
          Martis Creek Watershed	   329

 C-3      Summarized Suspended Sediment Data  Collected at North-
         ' star, October 1974 through September 1976	   333

 C-4      Suspended Sediment Site Locations in Lonely Gulch Creek
          Watershed  .,,,,.,	   336

 G-5 ,     Summarized Suspended Sediment Data  Collected at Rubicon
          Properties, October 1972 through September 1976   	   337

 C—6      Standing Crop Estimates of Benthic Macroinvertibrates
          listed by Family for West Martis Creek for all Stations
          Sampled during 1974,  1975, and 1976   	   339

 C-7      Standing Crop Estimates of Benthic Macroinvertibrates
          listed by Family for Lonely  Gulch Creek  for all Stations
          Sampled during 1975 and 1976	   345

 C-8      Summarized Monthly Flows and Suspended Sediment Loads
          Projected by Water Quality Model for Gage No. 1, West
          Martis Creek 	   347

 C-9      Summarized Monthly Flows and Suspended Sediment Loads
          Projected by Water Quality Model for Gage No. 2, West
          Martis Creek	   349

 C-10     Summarized Monthly Flows and Suspended Sediment Loads
          Projected by Water Quality Model for Gage No. 3, West
          Martis Creek 	   351
                                      324

-------
Number
 C-ll
 C-12
 C-13
Summarized Monthly Flows and Suspended Sediment Loads
Projected by Water Quality Model for Gage No.  4, Unnamed
Tributary to Martis Creek  	
Summarized Monthly .Flows and Suspended Sediment Loads
Projected by Water Quality Model for Gage  No.  5, Lonely
Gulch Creek  	

Summarized Monthly Flows and Suspended Sediment Loads
Projected by Water Quality Model for Gage  No.  6, Lonely
Gulch Creek	
                                                           Page
                                                                     353
                                                                     354
                                                                     358
                                       325

-------
                                  APPENDIX C

               WATER QUALITY AND'ENVIRONMENTAL MONITORING DATA
INTRODUCTION

The material in Appendix C is  a more extensive presentation of much of the
hydrologic and water quality data which is only briefly referred to Section
VII of the main report.   Included on the following pages are the following
Tables:

Table C-l:     Water Stored as Snow for each 105 Meter (500 Feet) Contour
               Interval  at Northstar.  Presented is a summarization of the
               water content of snow pack measurements taken at six sampling
               sites at  Northstar during 1975 and 1976.  The original data
               at each site is assumed to be representative of conditions
               found in  succeeding  150 meter contour intervals from the
               lowest elevation of  the Northstar development to the top of
               Mt. Pluto.   Estimate of total water content of snow pack at each
               sampling  date is also included.

Table C-2:     Suspended Sediment Sampling Site Locations in West Martis
               Creek Watershed.  Presented is a brief description of
               suspended sediment sampling stations located in the West Martis
               Creek (Northstar) watershed.  Included is description of
               drainage  area above  sampling site listing types of
               disturbances, if any.

Table C-3:     Summarized Suspended Sediment Data Collected at Northstar
               October 1974 through September 1976.  Presented is a
               summarization of the suspended sediment samples collected at
               Northstar at each sampling site for each runoff type:
               Lowflow,  Stage  I Snowmelt, Stage II Snowmelt, and Rainfall.  A
               total of  571 samples were collected and analyzed.

Table C-4:     Suspended Sediment Sampling Site Locations in Lonely Gulch
               Creek Watershed.  Presented is brief description of
               suspended sediment sampling stations located in the Lonely
               Gulch Creek (Rubicon Properties) Watershed.
                                      326

-------
 Table C-5:
Table C-6:
Table 0-7:
Table C-8:
  (through
Table C-13:)
 Summarized  Suspended  Sediment Data  Collected  at Lonely  Gulch
 Creek  (Rubicon  Properties) October, 1972  through September.
 1976.  Presented is a summarization of  the suspended
 sediment samples collected at Norths tar at each sampling site
 for each runoff type:  Lowflow, Stage I Snowmelt, Stage II
 Snowmelt, and Rainfall.  A total of 301 samples were collected
 and analyzed.

 Standing Crop Estimates (number of individuals/m2) of Benthic
 Macroinvertebrates listed by Family for West Martis Creek
 (Northstar) for all Stations Sampled during 1974, 1975 and
 1976'  Summarized data for nine sampling stations in West
 Martis Creek.

 Same as above for four stations in Lonely Gulch Creek
 (Rubicon Properties) during 1975 and 1976.

 Summarized Monthly Flows arid Suspended Sediment Loads
 Projected by Water Quality Models.   Based upon
 suspended sediment concentration vs. streamflow relationships,
 and continuous streamflow records  at four West Martis Creek
 and two Lonely Gulch Creek gaging  stations.   Estimated
suspended sediment loads for the four different runoff types
during each month of record,  at each gage is  presented.
                                    327

-------






























rH
QJ)

s
s

























a
o
H



vo
EH
CO
o


5!

1 ^
H
H
52
M
ei
S3 VO
g s
z; _.
o fx;
CO •*
£• S •*=
E-> O
W H
W N--'
O <2
0 W
in EH
o
(g CJ
w
EH pd
S tj =S=
o Js
m
r-l X
O
5 CM
w s
o
P4 2:
O CO
CM
O
CO

CO

Q
r^i
o
H
CO
Pd =«=
8
3


CM
e
AS
oo m
CM CM
rH
CM""
A!
vo r**«
VD CM
S °



S~i
CM

5 R
CM O
^^




CM
J
OO 00
CM O
^1" rH
"



CM_
e
t*f,
O ""»
CM ooco o-vocor-H ( ^o
rHCMCOCOCOCOrHrH 1 OOrHrH 1 ^
o
M

5-
pi
o
•H
OvocOCOrHvoOO OvOOO •"
SrHintTiOOOOrH CM CO VO VO t ®
O^r^rHrHrHrHl |OOOOICO

•H

rH
M
^,

CO
Sg3cS3^S g 8 3 3 S
Q^rHrHrHrHOI loOOOIg

O

i-l
(U
IH
0)
Pi

COvOicoin
328

-------
                                    TABLE  C-2

                  SUSPENDED  SEDIMENT SAMPLING  SITE LOCATIONS  IN
                         WEST MARTIS  CREEK WATERSHED

 Site  !•    Gage No.  1.  Stevens  gage above 1.22 meter  rectangular weir.
 Located near  the Big Springs  day  lodge on  the west  fork, West Martis  Creek.
 Drainage area above this point is 294 hectares and  extends  to the  summit of
 Mount Pluto at an elevation of 2620 meters.  Approximately  113 acres  of fores
 land have been cleared for ski trails.  Flow over this weir is principally
 overland flow as spring water is  collected via an underground collection
 system above  this point.  Groundwater collected by  this system is  transported
 either to the water treatment plant or through a bypass mechanism  to  the
 V-notch weir  (Site 5).

 Site 2.   Gage No. 2.  Stevens gage above a 90° V-notch weir.  Located
on east fork of West Martis Creek above the confluence with the west fork.
The drainage area .above this point is 471 hectares.  A 2.0 x 105 cubic meter
storage reservoir is located 2.4 kilometers above this sampling site.  All
surface runoff is collected by this reservoir which only briefly overflows
in the spring time of some years.  A groundwater collection system is
located above this reservoir.  A bypass valve spills excess water to the
east fork about one-third of a mile below the reservoir.  Extremely low
flows have been observed in the east fork at this point due to the
limitation of bypass flow from the groundwater collection system when the
treatment plant is on.

Site 3.   Gage No. 3.  Stevens gage above a 1.8.3 meter retangular weir.
 located on West Martis Creek below a bridge approximately one-eighth
mile north, of th.e golf course club Louse.  Samples taken above bridge
crossing the creek.  Drainage area above this point is 1308 hectares.  The
majority of the Northstar development is above this point.

'ite 4.   Gage No. 4.  Stevens gage above 1.22 meter retangular weir.
Located on unnamed tributary to Martis Creek.  Drainage area' above this
point is 220 hectares.  Meadow, pasture, and timber areas are located
above this sampling point.

 ite 5.  'V-notch weir.  Sixty degree V-notch weir located 1.22 meters
east of Gage No. 1.  Flow consists of overflow from the Big Springs
groundwater collection system.  Flows have been seen to range from
approximately 30 liters/sec when the treatment plant is not functioning
to as low as 2.25 liters/sec when the treatment plant is on.

 ite 6.   Village Culvert.  1.22 meter CMP draining Northstar Village
and parking area.  Discharging to the west fork of West Martis Creek
about 100 meters NE of the village center.   The total draining to the
                                     329

-------
 ABLE  C-2 - continued
sriLllage  culvert  is  80 hectares.   70 hectares or 88 percent of the total
 rea does not include any man-made disturbances.  The lower 10 hectares
 f the drainage  contains 0.6 hectare of paved roadway, 2.0 hectare of
 aved parking area, 0.2 hectare of structures, 0.4 hectare of unrevege-
 ated oversteepened cut slopes.   These structures, paved roadways,
 arking  lots, and  cut slope surfaces drain directly  to drop inlets and
 ubsequently  to  the Village Culvert.

 ite 7.   West Fork of West Martis Creek  just above  the discharge point
 f the Village Culvert.
 ite 8.
	      Trapezoidal weir  with staff gauge on the west  fork of West
 artis Creek above the contours with the East  Fork.   The total  drainage
area above the T-weir is 560 hectares including the  ski  area and  village
center.

jite 9.   Overflow or bypass valve from the Sawmill  Flat groundwater
collection system on the east fork of West Martis  Creek  at the  point
 rhere Big Springs Road crosses the creek.

Site 10.  East Fork of West Martis directly above  Big Springs Road.
 lurface drainage is apparent at this point only when there is substantial
overflow from the reservoir.

Site 11.  Drainage from unpaved dirt road into East Fork of West  Martis
Creek.
Site 12.  East fork of West Martis Creek below Big Springs Road and the
sawmill valve.

Site 13.  Rock lined drainage ditch from Unit 1-B discharging to West
 lartis Creek about. 60 meters below the confluence of the east and west
 forks.  The Unit 1-B drainage area is 4.1 hectare.  This drainage area
 has 0.75 hectare of paved surface area and 0.4 hectare of condominiums.
 Hence, approximately 28 percent of this drainage basin is covered with
 impervious surfaces.
 Site 14.
 ^^ J.-T.  A drop inlet collecting drainage from the upper reaches of
 the parking lot across Norths tar Drive from the village.  The drop
 inlet is located at the north end of the parking lot near Big Springs
 Drive.  The entire drainage area is 7.7 hectates.  The total paved
 parking lot surface draining to this drop inlet is 0.6 hectare.' Cut
 slopes adjacent to the parking lot area are approximately .22 hectare.

 Site 15.  A drop inlet collecting drainage from the middle bay  of the
 parking lot across Northstar Drive from the village.  Total area of
                                      330

-------
 TABLE C-2 - continued
  this drainage is approximately 0.80 hectare.  Paved surface  area is  0  4
 hectare and cut slope surface area is 0.1 hectare.  Drainage  to  this
  drop inlet eventually flows to the village culvert and subsequently  to
  the west fork of West Martis Creek.

 S*te 16.-  A drop inlet collecting drainage from the southwest corner of
 the_uPPer reach of the parking lot.  Total surface area of this  drainage
 basin is 9.3 hectare.   Ninety-nine percent of this drainage area is
    nnf?ed>  Cut sl°Pe area at the lower-reach of this drainage basin
 is 0.06 hectare; 'paved surface adjacent to the cut surface is 0.08
 hectare.

     , 17'  Discharge of drainage ditch to the west side of West Martis
 Creek about 30 meters  south of the Northstar Drive.  Total area  of this
 drainage is 108 hectare.   The  only direct discharge from a disturbed
 area to this drainage  ditch is from Site 14.   The Goldbend Condominium
 units of Unit 1-C are  also located within this drainage basin, however
 any discharge from disturbed areas is  spread over undisturbed land
 Site 18.
          West Martis Creek directly ahove Site 17 discharge point.
 S:Lte  19-   Sampling point  is  at  the  end  of  the culvert under Northstar
 Drrve above  confluence with  rock lined  drainage  ditch approximately 100
 meters west  of West Martis Creek.   Drainage  is surface flow from waste
 water treatment plant site.

 Slte  20-   Sampling point  in  rock lined  drainage  ditch above Site 19.
     ?,1'  DrainaSe from Unit 1~A at discharge point  to  each  side  of
     ftrfrt -V- +- •? 1-1 r^t~r*.~1- -2	J_  _ 1     -»T  .-.      	
TT  .  -,,      -,   ~	—~~—C?1- f V/J.J.J.I- i~\j CCH-1JL O_LUfcI U-L
West Martis Creek just above Northstar Drive.  Total drainage area is
1.5 hectares.  Paved surface area which contributes to the majority of
the runoff from this unit is about .26 hectare.

Site 22-   West Martis Creek about 30 meters below Northstar Drive.
Site 23.  Small unnamed creek about 300 meters east of West Martis
Creek just above Northstar Drive.

Site 24-  Small unnamed creek about 1,000 meters east of West Martis
Creek just below Northstar Drive.

S.ite 25-  Small unnamed creek about 120 meters of West Martis Creek
just north of Basque Street
                        i

Site 2.6-/   West Martis Creek just north of Basque Street.
                                     331

-------
TABLE C-2 - continued
Site 27.   West Fork of West Martis  Creek about 10 meters  above the
bridge from the village parking lot to the recreation complex.

Site 28.   Overland drainage from condominium unit and concentrated
across fill slope which forms the ski run at the bottom of the
transport lift.  Drainage is to the west fork of West Martis  Creek at
the recreation complex bridge.   The total area of this drainage is
approximately 10.5 hectares.  Fill area comprising the ski run-out
area at the bottom of the transport lift about 1.2 hectare.  Impervi-
ous paved parking lot and street surface areas from which flow  is
concentrated across the ski run has an areal extent of 0.5 hectare.

Site 29.   Middle Martis Creek above confluence with Martis Creek.
Site 30.  West Martis Creek just above confluence with Martis Creek.

Site 31.  Martis Creek just above confluence with West Martis Creek.
                                       332

-------




.



9
e
CM

:
ON
f-H
OS
S
8
8

§
1


§
u
8
i -
Q
Id
CO


w
CO
CO
a
w
t-H
CO
eo
u
3










M
I-H
c
a








M
s
S3







g
fe
s



a)
•a i
qj 55







I

Q

(j
i
<
H o
CO CH


W
O
<
«

u
• o


CO
s
Bu


1
O
CM to
CO


5

r-.
1
o o
 o
s


ON
•-


en
f-H


en
a
s
o

vO
O ON
f-H CM
CM

t—i
VO

ON
N \O
m in
ON

ON
CM

00



CO O
en f-H
CM

CM
ON


r— I
i-H
O
CO


en
CM
CM


m


00
3 la

0 0
f-H O
•—I

m
in

CM
io
0 -*
f-H

CM
en

in



o o
O CO
-»

00
en
f-H


in
> 0
o
•

sO
CM O
ON
*-H

CM
O

f-H
r-H
1
en I-H
23

0
o
CM

m



CO
0
3


en
f-H


en
CM

i-H
CM

CM
m


*

cj
r- 1
f-H
TT 	
r-.
o
CO
i-H

m
i-H
cn
i-H
I
0
2S
en

o
CO
ON

CO




—i in

VO
en
r-H


£
NO
CO


OO
f-


r-


a


1 O
in vo
VD

en
in
ON
ON

1 CO
f~ O-N
CM

VO
0

0
"*


o
CM O
O
CO


tn
o
CM


f-H
CM
> O
t-H


00
in


CM


• H
f

CO
1 -H
O -H

r.
in

-
io
O P~

in
O
CM

VO



CM
> -*

in
.n


ON
00



CM



VO


I •
1 .i
co ID


1 I


I

0



CO
f-H






1 1


1


O
vd
CM


VO
CM


r-t

CH
CO
3 m f
H f-
» > <
JO 4
H .£» *r
0 < D


1 O
r* CM
fH

^
fV'
CM

1 O
ON r-f.
CM I-H
CM 
-------
 s.
      §
334

-------

































•o
Si
.S
§
CO
0
u
1
H







p





l-l
8
E-i
CO





M
W

S
CO




1
s
2




0)
11








1 1
CO PK


w
o
w
5j
00
1
19

§
Of
8


-5

to
1 *:
!
H
S
5



s











o









0









o







o
B
cd
^
u
5








o



^

s
•*


f-H









o







o
CO'
SS
•°
CO








o

1
-3-
o
i- •*
vO
in

CO
CM

CO









o
s
cs
8




CO


u
CO
1
CO
O CM
i-H

-a-
CO






CO O
-4- CO
CM CO
CM
VO


CM
O
CO

O
CT\
CO





O
CM

8
o
VO



i— 1
09
«

0
1

"1 O
CM -3-
CS


O
*— 1

CM
CO

I
M
CO O
CO ~H
vO
O


-

coS
«-t en

t— t
i-H
CN



cn







o
Jg
o
i
i
CM
in o
^f
CO
CO

o
CO
CM
CO
CO '



-H
CM O
§

O
CO
CM
-

O
CO
o
CO

0

CO










o
4J
U-l
•H
1
E-"
I
-H in
in co
cO

ON
in
.-H






O
CO CM
a
VO
S



CO O
t~ CM
in r.

5
vO




CM
CO
o
CO
•*




-
4J
u

a

CO
Cv

CO
ON







O C7%
i-H i—i
^
st


in
v.
ss
^^
(-H
«— t




~*
CM
CM
VO
5




CO


<8

-3-
m vo
CM

m



en



vD
en co
r-<
vO
cn

CO

m


m




>— i
vO
•-H
•-H
VO




CO

g


















































cs








en
i-H









2











335

-------
                                   TABLE C-4

                SUSPENDED SEDIMENT SAMPLING SITE LOCATIONS IN
                         LONELY  GULCH  CREEK WATERSHED

Site 32 - Above a small reservoir  on Lonely Gulch  Creek and  above  all
          development.

Site 33 - Located 200 meters below Site 32 and just below  the  small
          domestic water supply  reservoir. It was located upstream  of  all
          disturbances  and drainages from Rubicon  Properties Subdivision.
          Gage No. 5 flow recorder located here.

Site 34 - Approximately 130 meters downstream of  Site  33 at  Rubicon  Glen
          Drive and below a third major drainage  swale draining the
          subdivision.

Site 35 - Located 170 meters below Site 34 and immediately above Highway 89
          and below a fourth major drainage swale.

Site 36 - Located 800 meters below Site 35 at Gage No. 6 flow recorder and
          below the majority of Rubicon Properties Subdivision development.

Site 37 - In Lake Tahoe ,at the mouth of Lonely Gulch Creek and about 180
          meters downstream of Site 36.

Site 38 - Brook Street Culvert No. 1 carrying surface drainage from Forest
          View Drive.

Site 39 - Drainage  ditch at  lower end of Highland Drive.

Site 40 - Drainage  ditch at  lower end of Highview Drive.

Site 41  - Brook Street Culvert No.  2  carrying  surface  drainage from Highland
          and Highview Drives.

Site 42  - Brook Street Culvert No.  3  carrying  drainage from Upper Lakeview
          Drive.

 Site 43 - Brook Street Culvert  No. 4  carrying  drainage from Upper Lakeview
          Drive.

 Site 44 - Upper Scenic drainage ditch carrying surface drainage  from North
          Lakeview, South Lakeview, Manzanita and Upper Scenic Drives.
                                       336

-------








vO
r*.
•-H
W
IS
w
CO


CM
O\
~
1
8
55
0
M
§
v^-
I
s

a
3
td
S
§
EH
O
ia
0
%
g
S
Q

§
Z
w
CO
CO
Q
C^3
CO
i
3
ta















H
W
C.
, E-
co










u
E-











1
O
•^

0)
•s i
re z









£




S
2
w
t
a
g


c


[E
i
0

w
o
1



CO
CL


I
Pfi

O
S-
"*

CO
H

,
*^~
^H m
u-i
CM


«> V
•
O 4


1 CO
OO CO
t— 1


00
vO
vO


CM



in
en
in

in




m


o
m
vo
o

o
in




co


1 vo
O CO


CO
vo


S
: «
i) a
J 00
•i re


o



o


t




1 1

1




o


CM
1


CM




CO


CO



CO


-
H
CJ
T 	
CO
CM O
CM



CO
CO


o\




1 1

I




o


o
s§
in


o
in
.— i




r-.


1



1


O
•«=
•g
o


1 O
o o
ON OO
.-H m



8
in
m
CM
vo




1 i

I




o


1


1




o


1



1


o
•a
c
re
r-l
60


i§
CO O
vO —1
CO
CM

O
O
in
VD

00




1 1

1




o


o
in o
t-H •— 1
CO *3-


o
t-H
CM
CM




CM


1



1


O
3

-------
338

-------

o
MH
£
0 VQ
cd r—
rH
G
id cd
cu
1 1 ^
co m
•H i*-
i-J cn
H
CO
cu «
S en
•H
4J 60
!-< 1=1
CU -H
£ 3
•H O
O
H T3
o cu
Cd rH

C3
a cd
•rH W
4J CO
G G
CU O
vQ M -H
1 4J
u m cd
O 4J
M CM rH
< ^ H
co
rH !-l
cd o
3 MH
•PI **"""S
•H cd
T3 4J
G to
4J
MH !H
°§
cu
r\ ^
H CU
3 CU
a !H
CO CO
Q) >rl
1 J 1_J
cd n
CO -U
W CO
0)
g,{3
CJ

60
13
Cu
4-1
CO





in
0

!r
>-
1














er

vC

•CL
rQ
1
•QJ
•01









• •
cu
4-1
•s
G
O
•H
4J
a
cu
rH
rH
O
u
1
go
i
gOO
1
s r~^

S vO
&
1

^•*
^
!
S co
^
1
§ CM
1
pTj Q



^oo
1
§•"
1


i10

,
S"*

I
gn

1
S cs
g
,
i"1


••
&
o
M
a
C/3


OOCM C0r2r^^; •* f^f- t^lrH rHCM CMt~-
OJCM S^0? ^TOOOOrHrHO CM
r~1 I — I i — 1 rH r— ( CM

U3rH  p.)
o IN- rx, 00-3- rx - Cn rH CM

*5riv2'~i0^rH mcM in rnr^- COr^vS-rHOCO CNOO
^oo CM.OCM ,* encMco-* CM
i j— j

CO CO CT\ 1 tf\ vft ro -f fy"i w\
S inrHOrH CM LOCMrxrH rH
oco^cocn00 mooin co rH co.
^
cd cu
O) T3 0) Cd 0)
t5 ^] ^ ^ ^u cU'Hcd'cJ cdcu
H^ rHQ)-H2T:>a'HMn:l'Hro * *" ^
w S O_. 1Q_. »3 r^ ^J «^J ^J rrH "t ^^ '
g o w Ii 3 S rH o"o°rH 8o"o2 cd'oS S |^3 S-n'^'s'oo'cu'^.'a
•—I 53 F**-! rO tTJ pi] pi O S Q-i CU Cu 1— i Cu •_!! e? {^ i_J IT^* Jj r> r i 1^ r ^ S /5 ^
5M E^ , .13 g
339

-------
                                                                    oo
               oo
                                                                                                        oo
                                                                                                               CM
     m
           co
           co
                                                                                                        VO
               VQ
      CO
                                   CM
                                   CM
                                                                    vo
                                                                    ON
                                                                    CM
                                                                                VO
                                                                                OO
                                                                                CO
                                                                                VO
                                                                                                               VO
                                                                                                         vO
                                                                                                         m
                                                                                                         m
                CO
                                                                     CM
                                                                              CM
                                                                                VO
                                                                                I~~
                                                                                m
                                                                                                               CM
                CM
                                                      m
                                                      CM
                                                                                                  CM
                                                                                                         oo
                                                                                                               CM
                                    CM
                                                              CO
                                                                     CM
                                                                     
-------





















^
cu
3
d
•H
4J
d
o
o
v~^
vO
U
W
3
E"1
























vO
O^
H
CO

CU
d
3













m
CT\
rH
ccT
CU
••9
cu
o
cu
Q











*•
(Collection Date
i
a o>

i

i ^

i
&"
2 in
^

I

.
^j CO

j.
S CM

S O-i
12
!
g 00
^
1

^

i


*gj LTJ

|
2 . CM
CJ\ Sf
CO

in in
rH

Sf CO
r^ oo
CM
m vo
m oo
rH

rH m
r-- vo
oo
O> CM
VO VO
in rH

sf in
CO CM
sf r-
sf

o m
in rH
rH

Sf OO
o oo
rH CM

CO CM
VO rH
CM rH
CO
CM

CO
rH
CO

oo r~-
CM
CO

VO I —
CM
rH

CJ\ 1^*
rH Sf
I — I



AKTHROPODA
INSECTA
EPHEMEROPTERA
Baetidae
Heptagenidae
PLECOPTERA

 sf
CM


rH

Sf Sf


sf sf












m
Hydropsy chidai
Limnephll idae
DIPTERA

sf CM
CM

cr\
rH

*^" C3
in

OO OO
rH rH
rH Sf
o in
rH


rH
CO rH
Sf 1 — I

r-~ oo
rH
Sf CO
in

P-N O^
CM

p^



m CM
in rH
rH VO
O^ C3 *vt*
CM CM
CM

T~H r^
iH -






























Heleidae
Ephydridae
341

-------







VO

rH
„
CO
I









T?
0)
a
0
•ti £
cJ o\
8 *
**~S r\
00
vO
I ^
o u
w "s
i_j S
a o
-
CO CO
rH
rH P~
0
rH
^ H *rH pi-l H~i *rH
W «H 0 P'^ScQM'HgQ'^
H'rlpLi }HTH'rlOOQ'O W 00
tn o & &
in
oo
o


vo
00

ON
rH
in
m
i — i
-a-
3

r^



**

oo

"^


CM
rH
rH

,—|



^

m
CM

si-

o
oo

ANNELIDA
Oligochaeta
PLATYHELMINTHES

CM ST ST
CM rH





O CM OO
O\ CM rH

r^


CO CM

VD
0
OO
rH
ON
OO
CO
rH
-vl-
VO
CO
rH
m
oo
rH

-------
T3
 cu

I

•M
 &
 O
 O
vo

i
FQ
       vO
       m
       rH
 CU
,0

s
 O
O
                 oo
                               r-^oo        -*     st o
                                   m        rHrHin
                            in


                        CTi  0-)     OO CM
                                                       oo
                                                                     cy.rofO,r-.o
                                                                     ^ooo-)            in
                                                                            CN
                                                                 5=
                 CM
                               mo
                                                       CM
                                                                           CM

                                                                           rH
                                                                                                              CN
Collection Da
                                            i3
                                            •H
                                                    cd
                                                    n)
                                                   T3
                                                                 cd         cu
                                                                 T3         ca
                                                                 >H|      "^
                                                                 -HOCU-H

                                                                                   td na js -H
                                                                                  Tj-HOrH
 cu
 cd
-a     cu

                                                                                                              CU
                                                                                                              (5     cu
                                                              343

-------
13

^£


|
|s* oo
^E

1
i"

gvo
I
y* iO
5
i
s "*

i-
^ CM

!z
1
g
V


	 . _Q ^-1.
"3" ' | ^-.J
p>. r—1
r^*

_ ~t*
rH r^ v*p
cri ;°
rH CM

l^s rH CO
CM CM

CM C1"1

«^J- VtJ
in •*
CM
° ' rj CM
CM *-l
CM 00 
-------





























•*•»
1
u

w
Q
*3j
E-H
























S-l
O
£
Ctf \O
Pn r-^
o\
K^l T~H
rQ

*T3 pi
(U ctf
4-1
co in
•H r^
r-3 O\
rH
CO
CU 00
•£ s
Cfl -H
,0 d
•rl P
4-1
CU CU
> r-l
C ft
•H S
O ctf
O
^ d
Q
a -H
•H 4-1
4J 4-1
d C/D
CU
pq H
rH

O ^
/-N O
CM m
B
CO CO
rH CU
Cfl -H
3 4-1
13 ^-(
•H CU
> ft
•rl 0
13 rl
•rH
d
<4H O
O 0
•H
CU "3
rS p>j
S v—'
d
d rM
	 CU
cu
CO 5-1
cu o
4-1
•H rH
CO CJ
w
ft£
O CU
M d
C_3 O
^J
oO
cfl .
4-1






Vj

S
o

c










VO
1
oc
1









in
p^^
00
o
1
cs









m

I
oo
o

r*^

cu
4-1
cfl
0
d
0
•H
Collect


O -vt
O  rHLOCO mrH rH
' — 1
VO 00 vo i-^ 00
rHCM CO rH S P! ^S ^ ~*
^^
COO-*CM-^rH O> CT, CO P^-OOO rH
-d-COrH ^^CM00 ^~* ^
VO
CNlOO COiH <±O 2 ^rH ^"^
t~~1 ,— J ^-»- 1
I I "VJ I— 1

1^- m ~* rH ^f rH r^
•* ^0 rH rH rH <)•


cQ3 ~* rH ~* lH"* VO Sf
00 rH

 t^- r^st- •* o-
O OO ! — I CM CT\
rH


r^-cN t^-ooco CM r^ O-CMCM CNO in •* oo -o-
CMl^ -J-rH-a- CO CT\ CMCO CMO in rHu->
^^^ si* i — i
cu
, cu cu cfl. cu
•^5 cflcucucu cflTjcflcu
K CU 13 cfl- cfl ctf TS-HcUTSCfl cU
gJS ^m'^'5'1'-' 'HS-ICO.H13 ctf cU
« , T'S'n'M'1"'-.'"' rH4-ii3rd'H 13 CU ctf CU
< OO)'d'H!:!'HO'H CU-HCUcflcU'O cfl
^ r**t Ctf CU {^ ctf QJ »H CU «H Ctf S £2* rn I 'o M ni "^-1 rS rrS ^ "rf S^ "^
^ ^ el Q, *o »3 2 ^ "Zj 'S "r"'
JCJw'-d-SpMrH O O4JrH So"o3tfl 0lJC! ° ° '"c^'1"1 ° OlHlH>'-|'rl'T:t
^WK CU ftO MrH QrH M CUM >,'ftB >,cfl ftTJ iw'ft-HrH S ftcrfrH^1
S^Pl^^JH^F^-S ® 
-------
346

-------
347

-------
g
H
               348

-------
1
 I
              §
                   349

-------
       8 a
                      I

        ;
        -4
       2i
          8
         Q
         8
                             3

a  i
«
                    1
I
1
                            350

-------
g
ft
s
en
t-
g
s
3







i
!
§1
II
P O
1
it
II
§ a
"
s 8
PI
en
o
5
1

>•
a

*
-


SI
al
u
1








i

| |
Sp

s§
fr* M
%"
si
"1
M
§
a
r
i§
-
6
a
M
^|
>

-
f
•i X ||
gl
*«*
w c 1
o 1
"* II
II
5" '
" i
||
1
O%
in
CO
1 293000

o

0

o

0
3
0
s
^H
eo
o
n
M
n
n
5
•M
N
9\
O
0
if)
CO
10
CM

CO
OO
CM
CM
295000

o

0

o

o


°

"





sS
\o
312000
m
o
en
ro
m
CM
O
CM
CO
to

o

o
:
1
ro

235200





CO
CM
%O
CO
D
N

O

O

o

o
1
1








r*.
CO
CM
243000

o

0

o

o
>
J
CM







00
in
*
361000
CO
CM
O
CM
CM
CM
0
O

o

o
00
CM
|
1 .

182900





OO
CM



r-
0
0
o

0

o
CM
m
r
S







tn
CM
1470000

o

o
*£>
m
n
s
1087000
J
in
CM
|
i
>
CO
CO
CO





eo
CO
00
CM
o
o
0
to
s
CM
(O
00
CM
O
CO
CO
CM
CO
3
tn
%
CM
00
00698S


o







o
—1
o
0
o
0

o

0

o

o










o
r-1
o
0
o
o
n
vD
o
3
CM

o

o










o
m
n
o
o
0
o
CM
CM
CA
".
T)
o
CO
to
CO

0

o


o

o



1


CM
4992000

CO

0
o
f-4
to
CO


-------
352

-------
o
4J


fr*

4J
3

•H

H
 !
\l
         Sz
         ee
                     s
                        353

-------
g
u
      II
    1
       s
      •I
S
§
                          S
                          SI
                     354

-------
s i
                        355

-------
8 8
o
I i
0
i



ml
r—1
CM
w u
1 1

h-
u



tJ IA 3
i 2 1
•B s i
e u i
50
~ 3
3
CVJ
rH
H »
li
38
a
11
* X
SEDIHE
TON/MO
~
i
r
Si
I
x
g
H
i§
-
fl
fc«
U
S c
5

a



















§


















I


















CJ


















3


















1


















1


















1


















1

523000


n
•>
K
4
O
*£>
311700
*
5
CM
S
197800

0

0
2

O
O
o
CO

o

o

o

o

o

o
§
§
§
237000
^

o
o
o
•-H

1
.0
CO
>

o

o

0

o
ON
a
CO
s
i
I

o
o
CO
vO


00
l"t

o

o

o

0
o\
1
CM
O
O
TO
i
g


















356

-------
g
d.
a
c_
cc
g
a
i
1
i












! i
? 55
CVJ
O CO
en
W
3 8
H to








NO
r--
ON
: :
i tl


w
"






ft

is
g-
SEDDI
TON/MO
-
S

||
s=
p
14
E g
«
j
a i
•<
M
S

"g



m
CM
CM
*O
CM
CO
t-H
g
tn
£
167500

o

0


0

o
2
,_J
R
1

en
ON
en
O

o
o
NO
CM

O

0

0

o
o

>
5






i

0
ON
CM
cn

o

o

o

o
g

:







§

O
O
rn

0

o

o

o
o
o

1
g






CM
O
o

o
o

o

0

o

o
>

1







f".
m
r-.
0

§

o

o

o

o
1

1







en
CM
§

o
o
CM
s

0

o

o

o
g









o\
CM
O
t-t
o
o
o
30

o

o
ON
00
tn
CM
ON
>
O
o










0
0

I
•o
en

0

o

o

o










oo
ON
O
O

o
CM
s
s
en
3
o
en
CM
CM

o

=>










in
s
0

0
10
o
00
n
0
ON
NO
NO
i

o

o










m

o
CM
NO
en
5
NO
ON
cn
o
CM

O

o










r-.
NO
r-
O
O
O
CM
NO

I"
0
in

0
t-t
to
f-*

in
CJ
r-l

0
CO
CM


CM
in
cn
CO

0
o
CO
CO
CM

in
o
CO

o
in

357

-------
        3
i
IS
B&
a u

13
 S O
 *a
 ™
    I
                                S
                                CM
                                S
                       358

-------
359

-------
•5  s
   K
   M
   CO
                            360

-------
  	
361

-------
                               APPENDIX D   .

                        SOURCES OF  ESOSION  CONTROL
                           PRODUCTS AND SERVICES
Included in this appendix are lists of  numerous  commercial sources for erosion
control plants, seeds,  products and services which were used as part of the
erosion control demonstration project or may be  suitable for use in the Lake
Tahoe Basin of California and surrounding areas.  The lists are not complete
and do not constitute a guarantee of reliability or  quality of product or
service.  The California State Water Resources Control Board does not endorse
any supplies or providers of services.   No discrimination is intended by
omission.

I.   Plants and Seeds
Parts A, B, C, D, and E are listings of the various grasses,  legumes.
flowers, shrubs and trees, respectively, which were used as part
                                                                     wild-
                                                                    he
erosion'control demonstration project.   Numerical designations following
each plant species refers to the numerical  listing of plant and seed
suppliers contained in Part F.

     A.   Grasses

          1.   Agropyron intermedium (intermediate wheatgrass)

               .  Greenar - 1, 2, 3, 17
               .  Oahe - 1, 2, 3, 8, 14, 15,  16,  17
               .  Tegmar - 27, 35
               .  No variety given - 7, 12, 13,  18,  28,  31, 34

          2.   Agropyron trichophorum (pubescent wheatgrass)
                  Luna
                       - 1, 2, 3, 7, 8, 14,  15, 18,  24,  28,  31,  34,  35
                  Topar - 1, 2, 3, 13, 17, 18, 24, 35
                .  No variety given - 8, 12, 13, 28

                Bromus  enermis  (smooth brome)

                .  Manchar -7,8, 13, 14, 17, 18, 24, 28
                .  Lincoln - 8, 12, 14, 17, 18, 24, 28, 33

                Dactylis glomerata  (orchard grass)

                .  Potomac - 1, 2, 3, 7, 8, 13, 15, 17, 18, 24, 31, 33, 35

                                      362

-------
      5.   Festuca ovina  (hard fescue)




          .  Durar - 1,  2, 3, 7, 8, 13, 15, 17, 18, 24, 31, 33, 35



B.    Legumes




      1.   Astragalus cicer (Cicer milkvetch)




          .  Lutana - 2, 8, 13, 16, 28, 34




      2.   Lotus corniculatus (Birds foot trefoil)




          .   Broadleaf - 1, 2,  3, 10, 12, 13, 14,  15,  17,  18,  31,  33




      3.   Lupinus Spp.  (lupines)




          .   1, 3,  6, 9, 10,  19, 21,  22, 25, 26,  30, 31




     4.   Trifolium repens (white dutch clover)




          .   1, 3,  7, 8, 13,  17, 18,  24, 31, 33




C.   Wildflowers




     !•   Eschscholzia  calif.  (California poppy)




          .   1, 3,  9, 10, 21, 22,  25,  30,  31,  36




     2.   Gilia leptantha (showy blue gilia)




          .   1, 3,  9, 10, 22, 25,  30,  31




     3.   Linum perenne lewisii  (western blue  flax)




          .   1, 3,  9, 10, 22, 25,  30,  31




     4.   Nemophila maculata  (fivespot)




          .   1,  3, 9, 10,  22, 25, 30,  31




     5.    Oenothera hookeri (hooker's  evening primrose)




          .   1,  3, 9, 10,  22, 25, 30,  31




     6.   Wild  flower seed mixtures




          .   1,  3, 9, 10, 21, 22, 25,  30, 31
                                363

-------
D.   Woody Shrubs




     1.   Amelanchier alnifolia (service berry)




          .  11, 19, 25




     2.   Arctostaphylos nevadensis (pinemat manzanita)




          .  11, 22, 25, 26, 30, 34




     3.   Arctostaphylos patula (greenleaf manzanita)




          .  11, 19, 22, 25, 26, 30, 34




     4.   Artemisia tridentata  (basin sagebrush)




          .  3, 5, 11, 21, 22,  25, 26, 30, 31, 36




     5.   Atriplex canescens (fourwing saltbush)




          .  2, 3, 5, 19, 21, 22, 25, 28, 30,  31, 33




    . 6.   Atriplex gardneri  (Gardner's saltbush)




             not commercially available




     7.   Castanopsis sempervirens  (bush chinquapin)




           .  11




     8.   Ceanothus cordulatus  (snowbush)




           .  11, 19,  25,  30




     9.    Ceanothus prostratus  (squaw carpet)




           .  11, 19,  22,  25, 26,  29,  34,  36




     10.    Chrysothamus  nauseosus  (common rabbitbush)




           .  11,  19,  22,  25, 26,  28,  30




     11.    Cornus stolonifera (dogwood)




           .   11,  19,  25




     12.    Eriogonum umbellatum (sulfur flower buckwheat)




           .   3, 19, 22, 25,  26, 30, 31, 36
                                 364

-------
 13.   Lonicera conj ugalis  (double honeysuckle)




       .  11, 25




 14.   Nama lobbii (wooly nama)




          not commercially available




 15.   Penstemon newberryi (mountain pride)




       .   11, 20,  26,  29, 34, 36




 16.   Penstemon strictus (Rocky Mountain penstemon)




       .   not commercially available in California




 17.   Prunus emarginata (bittercherry)




       .   11




 18.   Purshia tridentata (bitter brush)




       .   3,  11, 19, 25,  26,  28,  30,  34




 19.    Rhamnus rubra (Sierra  Coffeeberry)




       .   no  commercially "available




 20.    Ribes  spp.  (Currant, gooseberry)




       .   11,  19,  25, 34




 21.    Rosa woodsia (Wood's rose)




       .   11, 19




 22.   Rubus parviflorus  (thimbleberry)




       .   11, 19




23.   Salix spp.  (willow)




      .  11




24.   Symphoricarpos spp. (snowberry)




      .  11,  19,  25, 34
                           365

-------
E.   Trees

     1.   Abies magnifica (red fir)

          .  3, 4, 9, 10, 11, 18, 19, 24, 25, 30, 31,  32,  34,  36

     2.   Abies concolor (white fir)

          .  3, 4, 9, 10, 11, 18, 19, 24, 25, 30, 31,  32,  34,  36

     3.   Calocedrus decurrens (incense cedar)

          .  3, 4, 9, 10, 11, 18, 19, 24, 25, 30, 31,  32,  34,  36

     4.   Juniperus occidentalis  (western juniper)

          .  3,,4, 9, 10, 11, 18, 19, 24, 25, 30, 31,  32, 34,  36

     5.   Pinus jeffreyi (Jeffrey pine)

           .  3, 4, 9, 10, 11, 18, 19, 24, 25, 30, 31, 32, 34, 36

     6.   Pinus lambertiana  (sugar  pine)

           .  3, 4, 9, 10, 11, 18,  19, 24, 25, 30, 31, 32, 34, 36

 F.   Plant  and Seed  Suppliers

     The suppliers are  listed in alphabetical order with numerical
     designations as referred to in preceeding  parts A, B,  C, D, and E.

     1.   Albright & Company, 3613 Brook St., Lafayette,  CA  94549
           (213) 442-3330

      2.    Arkansas Valley Seeds, Box 270, Rocy  Ford,  CO   81067
           (303) 254-7469

      3.    Berger & Plate Co.,  1 California  St., San Francisco,  CA   94104
           (415) 445-1553

      4.    California Division of Forestry Nursery,  5800  Chiles  Rd.,
           Davia, CA  95616 (916) 753-2441

      5.    Carter, Roy,  P. 0. Box 4006,  Sylmar,  CA  91342 '(213)  367-5811

      6.    Coates,'Leonard Nurseries, Inc.,  400 Casserly Rd.,
           Watsonville,   CA  95076 (408)  724-0651

      7.   Curtis & Curtis, Inc., Star Rt.,  Box 8A,  Clovis, New Mexico
           88101  (505) 762-4759

      8.   Eisenman Seed Co., Fairfield, Montana 59436 (406) 467-2521

                                  366

-------
  9.   Environmental Seed Producers,  Inc.,  P.  0.  Box 5904,  El Monte
       CA  91734 (213)  442-3330

 10.   Ferry-Morse Seed Co.,  Box 100, Mountain View,  CA  94042
       (415)  967-6973

 11.   Forest Farm,  990 Tetherow Rd., Williams, OR  97544
       (503)  846-6963

 12.   Germain's,  Inc.,  P.  0.  Box 12447, Fresno,  CA   93777
       (209)  233-8823

 13.   Jacklin Seed  Co.,  8803  E.  SpragueAve., Spokane, WA  99206
       (509)  926-6241

 14.   Mile-High Seed Co.,  Box 1988, Grand Junction,  CO   81501
       (303)  242-3122

 15.   Miller Seed Co.,  P.  0.  Box 81823, Lincoln, Nebraska  68501
       (402)  432-1232

 16.    Montana Seeds, Inc., Rt. 3, Conrad, Montana  59425
       (406)  278-5547

 17.    North  Coast Seed  Co., P. 0. Box 12185, Portland, OR  97212
       (503)  288-5281

 18.    Northrup King  & Co., P. 0. Box 12123, Fresno, CA  93776
       (209)  237-4731

 19.    Northplan Seed Producers, Box 9107,  Moscow, Idaho  83843
       (208)  882-8040

 20.    Cutwater, Harry, P. 0. Box 13709, South Lake Tahoe, CA  95702
       (916)  544-5160

 21.   Payne, Theodore Foundation, 10459 Tuxford St., Sun Valley,
       CA  91352 (213) 768-1802

 22.   Pecoff Bros., Nursery and Seed, Rt.  5 Box 215R, Escondido,  CA
       92025  (714)  744-3120

 23.   Perry's Plants, Inc. 19362 Walnut Drive, La Puente, CA
      91745  (213)  964-1285

 24.   Ramsey Seed, Inc., P. 0. Box 352,  260 S. Main, Manteca,  CA
      95336  (209)  823-1721

25.   Robin Clyde, P. 0.- Box 2091, Castro Valley, CA  94546 (415)
      581-3467
                            367

-------
        26.   Saratoga Horticultural Foundation,  P.  0.  Box 308,  Saratoga,
              CA  95070 (408) 867-3214

        27.   Sasaki & Sasaki's Farm, Rt. 1,  Box 173-B, Weiser,  ID   83672
              (208) 549-2434

        28.   Sharp Bros. Seed Co., Healy, Kansas  67850 (316)  398-2231

        29.   Siskiyou Rare Plant Nursery, 522 Franquette St.,  Medford,  OR
              97501 (503) 772-6050

        30.   S & S Seeds, 382 Arboleda Rd.,  Santa Barbara, CA  93110
              (805) 967-6927

        31.   Stover Seed Co., 598 Mateo St., Los Angeles, CA  90013
              (213) 626-9668

        32.   Tahoe Tree Company, P. 0. Box 488, Tahoe City, CA  95730
              (916) 583-3911

        33.   Valley Seed Co., P. 0. Box 1110, Phoenix, AZ  85001
              (602) 956-4656

        34.   Wapumne  Native Plant Nursery, 8305 Cedar Crest Way,
              Sacramento, CA  95826  (916) 383-5154

        35.   Winterfeld, Delbert F.,  Box 97,  Swan Valley, Idaho  83449
               (208) 483-2248

        36.   Yerba Buena Nursery,  19500 Skyline Blvd., Woodside, CA  94062
               (415) 851-1668

II.  Erosion Control Products

The following is a partial list of  erosion control products and  manufacturers.
The list is not  complete and does not constitute a guarantee of  reliability
or quality of service  or product.  This list  is not  meant  to endorse any
product, and no  discrimination is intended by omission. Products and
manufacturers listed below are those which were:
                                                             •
     .  used as  part of the  demonstration project,
     .  similar  to product used, or
     .  mentioned elsewhere in this report.
     A.   Wood Fiber Mulch

          Silva-Fiber Mulch
          Weyerhaeuser Co.
          Tacoma, WA
          (206) 924-2345
Conwed & Conwed 2000
Conwed Corp.
St. Paul, MN
(612) 222-3033
                                      368

-------
            Necco  Fiber
            National Erosion  Control  Co.
            Cotati, CA
            (707)  795-9210

      B.,   Straw  and Mulch Tackifiers

            Ecology Controls M-Binder
            Ecology Controls
            No. Hollywood, CA
            (213)  877-7645

            Dow XFS-4163-L
           Dow Chemical, USA
           Midland, MI
            (517) 636-2086

      C.   Mulch Nets and Blankets

           Excelsior
           American Excelsior Co.
           Sheboygan, WI
           (414) 458-4333

           .Conwed  Netting
           Conwed  Corp.
           St.  Paul, MV
           (612) 222-3033

      D.    Fiber Glass Roving

           Glassroot
           Pittsburg Plate Glass Co.
           Pittsburg, PA
           (412) 434-3131

      E.    Gabions

           Bekaert Gabions
           Terra-Aqua Conservation
           Reno, NV
           (702) 329-6262
 Terra Tack II
 Grass Growers, Inc.
 Plainfield, NV
 (201) 755-0923

 Petroset Soil Binder
 Phillips Chemical Co.
 Bartlesville, OK
 (918) 661-6600
 Jute Netting
 Ludlow Textiles
 Needham Heights, MA
 (617)  444-4900

 Hold-Gro
 Gulf States  Paper'
 Tuscaloosa,  AL
 (810)  729-5831
Landglas
Owens-Corning Fiberglass
Toledo, OH
(419) 248-8000
Maccaferri Gabions
Bellevue, WA
(206) 455-4567
       Erosion Control Contractors

The following is a partial list of erosion control contractors who have
hydromulching and/or mechanical straw mulching capability in northern
California and northern Nevada.  The list is not complete and does not
constitute a guarantee of reliability of quality or service.   This list
is not meant to endorse any contractor,  and no discrimination is  intended
                                    369

-------
by omission.  Generally, other local landscape or nursery contractors are
also available to perform other erosion control activities besides hydro-
mulching or mechanical straw mulching.
     A.   Northern California

          Cagwin and Dorward
          San Rafael
          (415) 454-3122

          Valley Crest Landscaping, Inc.
          Hayward
          (415) 489-1179

          Bibens
          Modesto
          (209) 545-1621

          Coberly-Plumb
          Visalia
          (209) 732-2216

          Enterprise Gardens
          Redding
          (916) 243-7170

          North State Nursery
          Ukiah
           (707) 462-0553

          Selby Soil Erosion Control
          Vacaville
           (707) 448-1664

      B.  Northern Nevada

          P & S Hardware
          Reno
           (707) 329-1392

          Angelo  Pecorilla
           Carson City
           (702) 883-1119
Contra Costa Landscaping
Martinez
(415) 229-1060

Sunshine Landscapes
San Rafael
(415) 924-2844

Cal-Kirk
Eureka
(707) 822-1168

Econo-Garden
Oakland
(415) 638-4161

Gary Justice
San Ramon
(415) 837-2787

Sci-Soil
Tulare
(209) 586-0117
 Howe Landscape
 Reno
 (702) 358-2888

 Unrue Turf Farm
 Minden
 (702) 782-3146
                                        370

-------
                                  APPENDIX E

                                   GLOSSARY



 abundance,  species  (richness):  A measure of  the variety  of biologic  species
      present  in  a community.


 angle of  internal friction:  The  maximum slope  that an unconsolidated soil
      may  assume.


 angle of  repose:  The angle between the  horizontal and the maximum slope that
      an unconsolidated soil material assumes  through natural'processes.

 annual plant:  A plant that normally lives  for  one year or less.

 aspect:   The  direction that a slope faces.


 asphaltic concrete  (A - C):  Asphalt and  aggregate construction material for
      roadway  pavement, shoulders, and dikes.

 bed load:  The sediment that moves by sliding,  rolling, or bounding on or
     very near the stream bed.


 bench:  Gently sloping stable area at the toe of a steeper slope.

 benthic:  Of or pertaining to the bottom of streams,  rivers,  lakes,  or oceans.

 berm:  ^A  raised and elongated area of earth for erosion control intended to
     direct the flow of water or suspended sediment.

 breast wall:  A short retaining wall used for stabilizing  the  toe  of eroding
     cut slopes.


 Caltrans:   California Department of Transportation;  the branch of  California
     State government responsible for the construction and maintenance of
     state and federal highways within California.

 check dam:  A small  dam constructed in a gully or watercourse  to decrease the
     streamflow velocity,  minimize channel scour, and  promote  deposition of
     sediment.


contour:   The shape  of a  land  surface  as expressed by  contour  lines.
                                     371

-------
contour line:  (a)  An imaginary line on the surface of the earth connecting
     points of the same elevation; (b) A line drawn on a map connecting points
     of the same elevation.

crown:  The uppermost edge or edges of a slope.

cut and fill:  A process of earth moving by excavating part of an area and
     using the excavated material for adjacent embankments or fill areas.

deposition:  The lying down of material because of reduction of carrying
     capacity.

detritus:  In aquatic biology, disintegrated or fragmented organic matter
     which is carried to and deposited in a stream, river, lake, or ocean.

diversity  (species):  A measure of the relationship between the number of
     species and  the total population of a biologic community; considered to
     be a very sensitive biological  index of environmental change.

drill  seeding:  Planting seed with a mechanical device which places the  seed
     at variable  depths into the  soil in relatively narrow rows, generally
     less  than one foot apart.

drop-inlet (D.I.):  A  structure  for  collecting surface drainage which  has
     been  directed to  it, and  dropping  the  collected  drainage water to an
      underground  conduit.

 eco-system:   A community  of  organisms,  its  interrelationships,  and the
      surroundings in which they live.

 ecology:   The interrelationship of organisms with other organisms  and their
      environment.

 equivalent cost:   The cost of labor intensive erosion control techniques if
      conducted by skilled landscape laborers with a total labor cost  of
      $16.25 per person-hour.

 erosion:  Detachment and movement of soil or rock by water, wind,  ice, or
      gravity.

 erosion hazard (rating):  A rating  system for determining the Degree which
      land disturbance would increase erosion rate from a particular area.

 evenness, species:  A measure of the equality of apportionment of individuals
       in a biologic community to various species present.

 fertilizer:  Any organic or inorganic material of natural.or synthetic  origin
      which  is added to a soil to supply certain elements  essential to the
       growth of plants.
                                       372

-------
 fertilizer grade:   The guaranteed minimum analysis,  in percent of the major
      plant nutrient elements contained in a,fertilizer material.   A 16-20-0
      fertilizer refers to  the percentage, by weight,  of N - P?0  - K 0,
      respectively.                                              5     *•

 gabions:   Rock filled, heavily galvinized wire mesh baskets used  for the con-
      struction of breast walls,  retaining walls,  revetments,  and  groins.

 grade:   (a)  The slope  of a road,  channel, or  natural  ground surface;  (b)  The
      finished surface  of a canal  bed,  roadbed,  top of embankment,  or bottom
      of excavation;  any surface prepared  for  the  support of constructipn;
      (c)  To  finish  the surface of a  canal bed,  roadbed,  top of embankment,
      or bottom of excavation.

 gradient:  The rate  of regular or graded  ascent or descent.

 ground cover:   Herbaceous  vegetation and  low-growing  woody  plants  that form an
      earth cover.

 grubbing:  The process  of  removing roots,  stumps, and low-growing  vegetation.

 gully erosion:  The  erosion process  whereby water accumulates  in narrow
      channels  and, over short  periods, removes  the soil  from this  narrow
      area  to considerable  depths, ranging from  30 to  60  centimeters to as
      much  as 170 to  250 centimeters.

 hardpan:   A hardened subsurface soil layer caused by  cementation of soil
      particles with  organic matter or with materials  such as silica,
      sesquioxides, or calcium  carbonate.

 herbaceous:  Vegetation that is nonwoody.

 hydromulching:  The mechanical application of a natural or synthetic mulch to
      a soil surface.

 hydroseeding:  The mechanical application of plant seeds to a soil surface in
     a water slurry, with or without fibrous mulch.

 imperveous, impermeable:  A material or device which is incapable  of being
     penetrated or passed through by moisture or water.

 indicator species:   Specific organisms whose individual populations may be
     analyzed to determine the degree of stress on an entire ecosystem.

indigenous:  Produced,  growing, or living naturally in a particular region or
     environment.

infiltration:  The flow of  a liquid into a substance,  such as soil, through
     pores or other  openings;  connoting flow into  a soil in contradistinction
     to  "percolation" which connotes  flow through  a porous substance.
                                     373

-------
innoculation:  The process of adding cultures of symbiotic microorganisms to
     legume seed to enhance atmospheric nitrogen fixation.
Lahontan Regional Board:
     Region.
Regional Water Quality Control Board, Lahontan
Lake Tahoe Basin:  The 1,310 square kilometer watershed of Lake Tahoe (eleva-
     tion 1,898 meters) in the Sierra Nevada Mountains of California and
     Nevada.

legume:  A member of the plant family, Leguminosae, the fruit of which is
     usually a pod that opens along two sutures when ripe, leaves are alter-
     nate, have stipules, and are usually compound.  Includes many valuable
     food and forage species such as peas, beans, peanuts, clovers, alfalfas,
     and vetches.  Practically all legumes are nitrogen fixing plants.

Lonely Gulch Creek:  A small creek draining a 237 hectare watershed on the
     west side of the Lake Tahoe Basin in California; the stream which flows
     through the Rubicon Properties development.

macroinvertibrates:  Invertibrate animals generally larger than .5 millemeters
     which inhabit stream bottoms or are attached to stones or other objects
     in a stream.

mulch:  Natural or artificial material used to provide more desirable moisture
     and temperature relationships for plant growth.

native plants or species:  A plant or species that is a part of an area's
     original flora or fauna.

natural  (background) level:  The natural concentration of potential pollutants
     in  the environment which would occur without the presence of man's
     activities.

Northstar-at-Tahoe:  A well-planned and constructed 1,036 hectare all-year
     residental and recreational development in  the West Martis Creek water-
     shed north of the Lake Tahoe Basin in California.

overhang:  The verticle, near verticle, or overhanging top section of a heav-
     ily eroded  cut slope, usually retained by root systems of plants surviv-
     ing above  the cut slope.

parent material  (soils):  The unconsolidated, relatively unweathered mineral
     or  organic matter,from which the surface soils have developed.

percolation (soil water):  The  downward movement of water  through  soil, espe-
      cially the downward flow of water in saturated or nearly  saturated soil
     at  hydraulic  gradients of  the order of  1.0  or less.
                                      374

-------
 perennial plant:  A plant that normally lives three or more years.

 permeability:  The capacity for transmitting a fluid.

 perveous, permeable:   Having the capability of being penetrated or  passed
      through by moisture or water.

 Porter-Cologne Water  Quality Control Act:   California  state law enacted in
      1970 which'established the State Water Resources  Control Board and estab-
      lished procedures,  including the collection of monitory remedies,  for
      maintaining high quality waters within the State.

 profile,  soil:   A verticle section  of the  soil through all  its horizons and
      extending into the  parent material.

 rainfall  intensity:   The rate at  which rain is falling at any given instant,
      expressed in centimeters/hour.

 retaining walls:   Structure used  to  support and retain  soil  at an angle
      steeper  than the angle of internal friction to  provide  a gently sloping
      soil surface above  the structure.

 Regional  Water  Quality Control Board,  Lahontan Region  (Regional Board):
      A branch of  California State Government,  headed by a nine member board,
      responsible  for  water  quality control,  subject  to  review by the State
      Board, within all watersheds to  the east  of the crest of  the Sierra
      Nevada Mountains  in California.

 revetment:  A facing  of stone or  other material,  either permanent or
      temporary, placed upon a highly  erodible, oversteepened slope to protect
      it from  erosion.

 rhizomatous:  Having a root-like  stem under or along the ground which sends
      out  roots from its lower surface and leafy  shoots from its upper surface.

 riffle:  A shallow portion of a stream with rapid turbulent flow.

 right-of-way:  Right of passage, as over another's property; a route that is
      lawful to use; a strip of land acquired for transport or utility
      construction.

 rill  erosion:  An erosion process in which numerous small channels of only
      several centimeters in depth are formed.

rip rap:   Broken rock, cobbles, or boulders placed on earth surfaces, such as
     the face of an oversteepened slope, for protection against erosion.

rounding,  slope:  The  modeling or contouring of roadside and oversteepened
     slopes to provide a curvilinear transition between several planes;  e.g.,
     tops, bottoms, and ends of cuts and fills.
                                     375

-------
Rubicon Properties subdivision (Unit No. 2):  An extremely poorly planned and
     constructed subdivision development on the west side of the Lake Tahoe
     Basin in California.

runoff:  That portion of the precipitation on a drainage area that is dis-
     charged from the area in swails and stream channels.  Types include sur-
     face runoff, groundwater runoff, or seepage.

scaling  (slope):  The process of reworking eroding cut and fill slopes to
     eliminate  unstable conditions and prepare a surface suitable for the
     establishment of vegetation.

scarify:  To abrade, scratch, or modify the surface; for example, to scratch
     the impervious seed coat of hard seed or to break the surface of the soil
     with a narrow bladed implement.

scour:   The wearing away of channel substrate on stream beds.

sediment:  Solid material, both mineral and organic, that is in suspension, is
     being transported, or has been moved from its site of origin by air,
     water, ice, or gravity.

sediment load:  The quantity of  sediment, measured in dry weight or by volume,
     transported through a stream  cross section  in a given time; sediment load
     consists  of both  suspended  load and bed load.

sedimentation:  The natural geologic or man-made process which includes
     erosion,  transportation, and  deposition of  solid particles by wind,
     water,  ice, or gravity.

seepage:  Water escaping through or  emerging  from  the ground along an exten-
     sive  line or  surface as  contrasted with  a  spring where  the water emerges
      from a  localized  spot.

 settling basin: An enlargement  in the channel  of  a  stream or  dammed area
      to permit' the settling of debris  carried in suspension.

 slope:  The degree of  deviation  of a surface  from the horizontal,  usually
      expressed in a ratio,  percent,  or degrees,  such as Ug:l (horizontal to
      vertical), 67 percent,  or  34  degrees,  respectively.

 slough:  Come off; fall away.

 sprigging:  The planting of a portion of the stem and/or root  of a plant.

 State Board:   State Water Resources Control Board, California.

 State Water Resources Control .Board, California (State Board):  A branch of
      California State Government,  headed by a five member board, responsible
      for water rights, water quality, and water pollution control within the
      State.
                                       376

-------
 standing crop:   In aquatic  biology,  an estimate of  the  number  of  individuals
      per unit area in a  community.

 stilling basin:  An open structure or  excavation above  a  flow  measuring
      device,  such  as a weir,  to  reduce the  kinetic  energy of the  flowing
      water.

 straw blowing:   The application  of straw mulch  to a soil  surface  by means of a
      mechanical  blower.

 stream environment zone:  Riparian area adjacent to streams containing sensi-
      tive vegetation and animal  life.

 subsoil:  The stratum of material beneath the surface soil.

 substrate:  The  bottom or benthic medium which  biologic organisms inhabit.

 swale:  A hollow or  depression.                           "

 tackifier:  A chemical agent used to bind mulch fibers  together.

 tacking:  The process  of binding mulch  fibers together by the addition of a
      sprayed  chemical  compound.

 toe:  The lower  edge or  edges of a slope.

 tolerant  (plants):  Capable of growth and survival  under competitive or
      adverse  conditions.

 topsoil:  The upper layer of soil containing organic matter and usually suited
      for  plant survival  and growth.   On a construction site, the topsoil
      should be saved for  topsoiling.

 topsoiling:   The practice of replacing  temporarily removed topsoil at a con-
      struction site once  construction activities have been completed.

 transpiration:  The process by which water vapor is released to the atmosphere
     by the foliage or other parts of a living plant.

 turbidity:  An expression of the optical property of water which causes light
     to be scattered or absorbed due to the presence of suspended matter.

waste, construction:  Excess sediment,  earth, rocks, vegetation, or other
     materials resulting from roadway,  residential,  commercial, or other
     building construction.

water bars:   Artificial barriers to  divert surface runoff from  erodible
     surfaces and to prevent accumulation of drainage water.

wattling, contour:   Bundles of live,  rooting plant species placed as  partially
     buried "cables" across  an eroding  slope at  regular contour intervals  and
     supported at the lower  side by  stakes.

                                     377

-------
weathering:  All physical, chemical, and biological changes produced in rocks
     at or near the earth's surface.

weir:  An obstruction placed in a stream or channel diverting the water
     through a prepared aperture for measuring the rate of flow.

West Martis Creek:  A small stream draining a 1,308 hectare watershed in the
     Truckee River watershed north of the Lake Tahoe Basin in California;  the
     stream which flows through the Northstar-at-Tahoe development.
                                     378

-------
                                   APPENDIX F

                              CONVERSION FACTORS^/


 Various conversion factors  are included in this  appendix for the convenience
 of the user of this report  in calculating areas, rates,  and volumes.
 Conversion factors are generally  shown for four  significant digits  suitable
 for field use with a slide  rule.   For office calculations,  more precise
 conversion factors of five  or more significant digits may be needed in some
 ins tances.
          To Convert
UNITS AND EQUIVALENTS

  Conversion Factors

         Into
                                                       Multiply By
     acre
     acre-ft
       Cac-ft)
   hectare
   sq feet Csq ft)
   sq meters Csq m)
   sq miles (sq mi)
   cu ft
   cu yds
   gallons Cgal)
   cu meters (cu m)
   tons  (short)
      0.4047
 43,560.0
  4,047.0
      1.562 x 10~3
 43,560.0
  1,613.0
325,850.0
  1,234.0
  1,359.0
     Celsius or
       Centigrade (C)
     centimeters (cm)
     cubic centimeters
       (cc)
  Fahrenheit  (F)
  feet  (ft)
  inches  (in)
  meters  (m)
  millimeters  (mm)
  cu ft
      1.8C + 32
      0.03281
      0.3937
      0.01
     10.0
      3.531 x 10  5
I/   National Engineering Handbook,  Chapter  10,  Section 3,  Soil
     Conservation Service,  USDA,  April 1971.
                                      379

-------
     To Convert
cubic feet
  (cu ft)
cubic feet of
  water
cubic feet/
  sec (cfs)
cu ft/sec/sq
  mi (csm)
cubic ft/sec
  (cfs)
cfs-days
cubic inches
  (cu in)

cubic meters
  (cu m)
cubic yards
  (cu yd)
      Into

cu in
U.S. gallons
  (U.S. gal)
liters (1)
U.S. pints
U.S. quarts
cu cms (cc)

cu in
cu meters (cu m)
cu yards  (cu yd)
U.S. gallons
  (U.S. gal)
liters (1)
pounds (Ibs)

kgs/sq cm
kgs/sq meter
  (kgs/sq m)
pounds/sq ft
  (psf)
pounds/sq in.
  (psi)
acre-ft per day
  (ac-ft/d)
acre-ft per year
  (ac-ft/yr)
million gal's/
  day  (mgd)
liters/sec  (I/sec)
cu m/sec
liters/sec/sq km
  (1/sec/sq km)
g aliens /min (gpm)

cu ft
cu cms (cc)

cu f t
cu ft

U.S. gallons
  (U.S. gal)
cubic yards (cu yd)
cu cms (cc)
  Multiply By

     0.06102
                                                              ,-4
     2.642 x 10

     0.001
     2.113 x 10~3
     1.057 x 10~3
28,320.0

 1,728.0
     0.02832
     0.03704
     7.481

    28.32
    62.43

     0.03048
   304.8

    62.43

     0.4335

     1.984

   724.0

     0.6463

    28.32
     0.02832
     0.0915

   448.8

86,400.0
    16.39

     5.787 x 10~4
    35.32

   264.2

     0.7645
     7.646 x 105
                                 380

-------
                                   APPENDIX F

                              CONVERSION FACTORS^/


 Various conversion factors are included in this appendix for the convenience
 of the user of this report in calculating areas, rates, and volumes.
 Conversion factors are generally shown for four significant digits suitable
 for field use with a slide rule.  For office calculations, more precise
 conversion factors of five or more significant digits may be needed in some
 ins tances.
           To Convert
UNITS AND EQUIVALENTS

  Conversion Factors

         Iii to
                                                        Multiply By
      acre
      acre-ft
        Cac-ft)
   hectare
   sq feet (sq ft)
   sq meters  Csq m)
   sq miles (sq mi)
   cu ft
   cu yds
   gallons (gal)
   cu meters  (cu m)
   tons  (short)
      0.4047
 43,560.0
  4,047.0
      1.562 x 10'
 43,560.0
  1,613.0
325,850.0
  1,234.0
  1,359.0
                                                                    ,-3
      Celsius or
       Centigrade (C)
      centimeters (cm)
     cubic centimeters
       (cc)
  Fahrenheit  (F)
  feet  (ft)
  inches  (in)
  meters  (m)
  millimeters (mm)
  cu ft
      1.8C + 32
      0.03281
      0.3937
      0.01
     10.0
      3.531 x 10~5
_!/   National Engineering Handbook, Chapter 10, Section 3, Soil
     Conservation Service, USDA, April 1971.
                                      379

-------
     To Convert
cubic feet,
  (cu ft)
cubic feet of
  water
cubic feet/
  sec (cfs)
cu ft/sec/sq
  mi (csm)
cubic ft/sec
  (cfs)
cfs-days
cubic inches
  (cu in)

cubic meters
  (cu m)
cubic yards
  (cu yd)
      Into

cu in
U.S. gallons
  (U.S. gal)
liters (1)
U.S. pints
U.S. quarts
cu cms (cc)

cu in
cu meters (cu m)
cu yards (cu yd)
U.S. gallons
  (U.S. gal)
liters (1)
pounds (Ibs)

kgs/sq cm
kgs/sq meter
  Ckgs/sq m)
pounds/sq ft
  (Psf)
pounds/sq in.
  (psi)
acre-ft per day
  (ac-ft/d)
acre-ft per year
  (ac-ft/yr)
million gal's/
  day  (mgd)
liters/sec  (I/sec)
cu m/sec
liters/sec/sq km
  (1/sec/sq km)
g aliens /min (gpm)

cu ft
cu cms (cc)

cu f t
cu ft

U.S. gallons
  (U.S. gal)
cubic yards (cu yd)
cu cms (.cc)
  Multiply By

     0.06102
                                                               ,-4
     2.642 x 10

     0.001
     2.113 x 10~3
     1.057 x 10~3
28,320.0

 1,728.0
     0.02832
     0.03704
     7.481

   ' 28.32
    62.43

     0.03048
   304.8

    62.43

     0.4335

     1.984

   724.0

     0.6463

    28.32
     0.02832
     0.0915

   448.8

86,400.0
    16.39

     5.787 x 10~4
    35.32

   264.2

     0.7645
     7.646 x 105
                                 380

-------
     To Convert
      Into
     Multiply By
days
deg F
cu ft
cu meters (cu m)
U.S. gallons
  (U.S. gal)
aere-ft

       D

second (sec)
deg C (Centi-
  grade or
  Celsius)
                                                    27.0
                                                     0.7646
                                                   202.0

                                                     6.19 x
   86,400.0


(F° - 32).5556
Fahrenheit (F)
feet (ft)
feet/min (fpm)
feet/sec (fps)
gal CU.S.)
gallons of water
  (gal of wtr)
gallons/min
  (gpm)
gallons/acre
  (gal/A)
Centigrade  (C)
centimeters
  (cm)
kilometers
  (km)
meters  (m)
miles (mi)
cms/sec  (.cps)
feet/sec  (.fps)
kms/hour  (km/hr)
miles/hour  (mi/hr)
meters/min  (m/min)
miles/hour  (mph)
km/hour  Ckm/hr)

       G

cubic cms (cc)
cubic feet  (.cu ft)
cubic inches
  (cu in)
gallons Br. Imp.
  (gal Br.  Imp .)
liters  (1)
pounds of water
  (Ibs of wtr)
cu ft/sec Ccfs)

liters/sec  (I/sec)
cu ft/hr
liters/hectare
  (1/ha)
(F°  - 32). 5556
       30.48

        3.048 x 10'

        0.3048
        1.894 x 10'
        0.5080
        0.01667
        0.01829
        0.01136
       18.29
        0.6818
        1.097
    3,785.0
        0.1337
      231.0

        0.8327

        3.785
        8.3453

        2.228 x 10

        0.06308
        8.0208
        9.353
                                                               r4
                                                               ,-4
r3
                                 381

-------
     To Convert
      Into
  Multiply By
grams (g)
gram of water
   (g of wtr)
hectares (ha)

hours  (hr)
pounds  (Ibs)
cu cm of water
  (cc of wtr)

       H

acres
sq feet (sq ft)
days
weeks (wk)
     2.205 x 10~3
     1.0 (at 4°C)
     2.471
     1.076 x 10
     0.04167
                                                     5.952  x 10'
                                                               —3
inches (in)
inches
  (watershed)
kilograms (kg)
kilograms/hectare
  (kgs/ha)
kilograms/sec
  (kg/sec)
kilometers (km)
centimeters  (cm)
cu ft/sec/sq mi
  (csm)

       K

pounds, (lh)
  avoirdupois
tons, short  (T)
pounds/acre
  (Ibs/A)
ton (short)/
  year (T/yr)
miles (mi)
     2.540
    13.584
     2.205

     1.102 x 10'
     0.8921

34,786.0

     0.6214
                                                               ,-3
liters (1)
liters/sec (I/sec)

liters/sec/
  sq km (I/sec/sq km)
liters/hectare
  (1/ha)
meters On)
cubic cm (cc)
gallons U.S.
  (gal U.S.)
cubic foot/sec
  (cu ft/sec)
cubic ft/sec/sq
  mi (csm)
gallons/acre
  (gal/A)

       M

yards (yd)
feet (ft)
inches (in)
 1,000.0
     0.2642

     0.0353

    10.93

     0.1069
     1.094
     3.281
    39.37
                                 382

-------
            To  Convert

      meters (m)

      miles  (U.S.
        stat)  (mi)
      miles/hour  (mph)
      mi 11 igr ams /1 i te r
        (mg/1)    •
      milliliters (ml)
      millimeters (mm)

      million gallons/
        day (mgd)
      minutes (min) (angles)
      ounces (oz)

      ounces/gallon
        (U.S.)
        (oz/gal-U.S.)
                                  Into

                            miles (stat)
                              (mi stat)
                            kilometers (km)
                            )
                            feet/sec (fps)
                            parts/million (ppm)

                            liters  (1)
                            inches  (in)
                            microns  (u)
                            cu ft/sec  (cfs)

                            acre-ft/day
                            cu m/min
                            degrees  (deg)

                                  0

                           grams (g)
                           pounds (Ibs)
                           gms/liter Cgm/1)
  Multiply By

     6.214 x 10~4

     1.609

     1.467
     1.000*

     0.001
     0.03937
     1 x 103
     1.547

     3.069
     2.629
     0.01667
   28.35
    0.0625
    7.489
     parts per million
        (ppm)
     pounds  (Ibs)
     pounds of .water
       (Ibs of wtr)

     pounds of water/min
       (Ibs of wtr/min)
                          milligrams per
                             liter (mg/1)
                          grains
                          grams  (g)
                          kilograms  (kg)
                          ounces  (oz)
                          tons**  (T)
                          cubic feet (cu ft)
                          cubic inches  (cu in)
                          gallons  (gal)
                          cu ft/sec  (cfs)
    1.000*

7,000.0
  453.6
    0.4536
   16.00
    0.0005
    0.01602
   27.68
    0.1198
    2.670 x 10~4
*
**
True within one percent when the concentration is less than 10 000
Throughout this report, tons means metric tons (2,205 Ibs) unless
otherwise indicated as tons (short) or tons (long).
                                     383

-------
         To Convert

    pounds/cu foot
      (pcf)
    pounds/cu in
      (pel)
    pounds/gallon
      (U.S.)
    pounds/acre
      (Ibs/A)
    rods
       Into

grams/cu cm (g/cc)

kgs/cu meter
  (kg/cu m)
pounds /cu in (pci)
gms/cu cm (g/cc)

gins/liter (g/1)

kilograms/hectare
  (kgs/ha)

       R

feet  (ft)
miles (mi)
Multiply By

   0.01602

  16.02

   5.787 x 10"
  27.68

 119.8

   1.121
                                                        16.50
                                                         3.125 x  10
                                                                   ,-3
    sq centimeters
      (sq  cm)
    square feet
      (sq  ft)
    square inches
      (sq  in)
    sq kilometers
      (sq  km)
    square meters
      (sq  m)
    square miles
      (sq  mi)
     square yards
       (sq yd)
     tons* (long)  (T)
square inches              0.1550
   (sq in)
acres (ac)

sq cms

sq miles  (sq

sq ft

acres (ac)

square feet (sq  ft)
square kms  (sq km)
square meters  (sq m)
square yards  (sq yd)
square feet (sq  ft)

square meters  (sq m)

       T

pounds  (Ibs)            2,240.0
   2.296 x 10

   6.452

   0.3861

   10.76

 640.0

   27.88 x 106
   2.590
   2.590 x 10*
   3.098 x 10fc
   9.0

   0.8361
             ,-5
*    Throughout this report, tons means metric tons (2,205 Ibs) unless
     otherwise indicated as tons (short) or tons (long).
                                      384

-------
       To Convert

  tons* (metric)  (T)
  tons* (metric)/
    sq  km
      (T(met)/sq km)
  tons* (short)
  tons  (short) /
   sq mi
 watershed in
 watershed inches
       Into

 kilograms  (kg)
 tons  (short)  (T)
 pounds  (Ibs)
 tons  (short)/
  sq mi

 kilograms  (kgs)
 pounds  (Ibs)
 tons  (long)
 tons  (metric)
 tons  (metric)/
  sq km
 tons (short)/acre

       W

acre-ft/sq mi
acre-ft (total)
 Multiply By

1,000.0
    1.102
2,205.0
    2.854
  907.2
2,000.0
    0.8929
    0.9078
    0.350
                                                                 .-3
                                                       1.5625 x 10
   53.33
   53.33 x drainage
     area (in sq mi)
 years (yr)
                           seconds (sec)
                          31.5576 x 106
^Throughout this report, tons means metric tons  (2,205  Ibs)  unless
otherwxse indicated as tons (short) or tons  (long).
                                 385

-------
                                  TECHNICAL REPORT DATA
                           (Please read Instructions on the reverse before completing)
  REPORT NO.
  EPA-600/2-78-208
                                                          3. RECIPIENT'S ACCESSION-NO.
 , TITLE AND SUBTITLE
 DEMONSTRATION OF EROSION AND SEDIMENT CONTROL
 TECHNOLOGY - Lake Tahoe Region of California
               . REPORT DATE
               December  1978 (Issuing Date)
              6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
  Charles A. White
  Alvin L.  Franks
                                                          8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
 California State Water Resources  Control Board
 Division of Planning and Research
 Sacramento, California  95801
               10. PROGRAM ELEMENT NO.

                 1BC611; SOS #2;  Task 17
               11.XHNXK3C U.S. GOVERNMENT PRINTING OFfICE: 1979-657-060/1568

-------