JUNE 1971

                     OF THE
                COLORADO, WYOMING
An evaluation of the Bureau of Reclamation's pro-
posed Savery-Pot Hook Project reveals that with
adequate treatment municipal and other minor waste
loadings will not significantly affect water quality
for present and projected water uses in the Project
area.  Therefore, no storage in Savery and Pot Hook
Reservoirs is needed to provide flow regulation for
maintaining satisfactory organic water quality in
the Colorado River.  The use of Project water for
irrigation purposes will result in a 2.5 mg/1 in-
crease annually in the total dissolved solids con-
centration of the Colorado River at Lake Mead.  The
economic impact of this salinity increase upon water
users below Lake Mead is estimated to be $165,600
annually, based on 1970 economic conditions.  This
appraisal provides an estimate of the effect of
salinity increases resulting from the Project and
will be useful in evaluating and justifying control
measures for water quality improvement.  Control
measures are recommended for incorporation into the
construction and development of the Project to mini-
mize the adverse effects of salinity.
         Environmental Protection Agency
                   Region VIII
                Denver, Colorado

                    June 1971

                    TABLE OF CONTENTS


Introduction 	   1

Water Quality in the Project Area	   2

Project Impact on Water Quality	   4

Storage for Streamflow Regulation	   6

Waste Source Control 	   7

Conclusions	10

Recommendations	10

References Cited 	  12

                         EVALUATION REPORT
                              on the
                      SAVERY-POT HOOK PROJECT
                             June 1971


     This report on the Definite Plan of the Bureau of Reclamation's

 (USBR) Savery-Pot Hook Project supplements the Public Health Service

report entitled, "Public Health Aspects of the Savery-Pot Hook Project,"

dated December 1957 and revised in April 1960.  The previous report

pertained to the USBR feasibility studies for this Project.

     A supplemental report was considered necessary because the

following events have occurred since April 1960:

      (1)  The enactment of the Water Pollution Control Act, as amended

          (33 U.S.C. 466 et seq.) and issuance of Executive Order 11507,

          dated February 5, 1970; transfer of the Federal Water

          Quality Administration (FWQA) to the Department of the

          Interior; and subsequent transfer of the Federal Water Quality

          Administration to the Environmental Protection Agency

          on December 2, 1970;

      (2)  The USBR requested an updated water quality report;

      (3)  Changes have been made by the USBR in the proposed

          Project plan; and

      (4)  The Environmental Protection Agency has completed a study

          of the economic impact of salinity in Colorado River water.

     The Savery-Pot Hook Project will provide water for irrigation,

recreational, and fishery purposes.  Principal Project features in-

clude two reservoirs;  Savery Reservoir on Savery Creek in Wyoming

and Pot-Hook Reservoir on Slater Creek in Colorado.   Both creeks

are tributaries of the Little Snake River, an interstate stream.

The Project reservoirs will supply 66/000 acre-feet of irrigation

water for full service to 17,920 acres and supplemental service to

14,330 acres, in both Colorado and Wyoming.

                 Water Quality in the Project Area

     A limited water quality survey was conducted by FWQA in

July 1970 along the Little Snake River from Slater, Colorado to

Baggs, Wyoming to check reported low dissolved oxygen concentrations

and high pH values.  The survey revealed dissolved oxygen concen-

trations ranging between 6.5 mg/1 and 7.7 mg/1 and pH values ranging

between 7.5 and 8.0.  The discharge ranged between 37 cubic feet per

second and 42 cubic feet per second.  It can be observed from the

tabulation shown below that the values for these parameters meet the

water quality standards criteria of the States of Colorado and

Wyoming for this reach of the Little Snake River.  Water quality

standards criteria for other parameters are also being met in the

Project area.

        Water Quality Standards for the Little Snake River

                                  Standards of Quality I/
 Designated Water      Bacteria   Dissolved                Dissolved
   Use for the          (Count/     Oxygen    Temp.          Solids
Little Snake River2/    100 ml)     (mg/1)     oF     pH      (mg/1)

                         State of Colorado

Public Water Supply   < 1,000*      >4       	   6.0-9.0    500

Cold Water Fishery    <1,000       >6      < 70   6.5-8.5    	

                         State of Wyoming

No use designated     <2,000**     >6       <78   6.5-8.5    	
Basic standards
I/ Adapted from State Water Quality Standards documents; refer to state
   standards for specific language and additional criteria.
2/ Little Snake River - from the source to intersection with county roads
   east of Powder Wash, Colorado (About 3 miles south of the Wyoming-
   Colorado stateline).

*Fecal coliforms (log mean value).
**Fecal coliforms (mean value).
   The minimum flow through the Baggs-Dixon area required to assimilate

domestic wastes and maintain a minimum dissolved oxygen content of 6.0

mg/1 is 1.0 cubic feet per second (cfs).   The assumptions used in cal-

culating the minimum flow requirements are as follows:

   1.  The Dixon and Baggs, Wyoming populations in 2010 will be

       200 and 400, respectively.

   2.  Each population equivalent contributes 0.17 pounds of five-

       day 20°C biochemical oxygen demand (BOD5).

   3.  Waste treatment facilities in the  Project area will remove 85

       percent of the BODg contributed by the entire population.

There are no industrial wastes in the area.   Examination of the U.S.

Geological Survey flow records for a 37-year period at a station near

Dixon indicates that the streamflow is greater than 1 cfs over 95 per-

cent of the time.  Generally, the low-flow periods occur during August

and September.

   The Project will cause a change in the low-flow pattern.  Presently

the irrigators divert most of the seasonal irrigation supply during the

spring runoff period because storage is not available.  During the latter

part of the irrigation season the irrigators divert most of the available

streamflow.  After the Project is built/ a fairly constant supply of

water will be available throughout the growing season.  Because of the

complex pattern of water rights, diversions, and return flows in the

Baggs-Dixon area, it is difficult to determine the precise flow of the

Little Snake River in that area during the irrigation season.  However,

since high priority water rights downstream from Dixon will be met after

the Project is built, it is anticipated that the minimum flows during

August and September will exceed those occurring before the Project is

built.  Therefore, these flows will be more than adequate to meet the
minimum flow required to assimilate domestic wastes.  A discussion of

the mineral quality of water in the Project area is included in the

following sections.

                  Project Impact on Water Quality

   The major impact of the proposed Project on water quality will re-

sult from increases in salinity (total dissolved solids) concentrations

of the Colorado River.  A comparison of the average annual pre-project

and post-project flows and total dissolved solids (TDS) concentrations

at three locations downstream from the Project area is shown in the

tabulation below.
River Location
in TDS
Little    Near Lily,    451,000    196       424,400    224      + 28
Snake     Colorado

Green     Ouray,      4,505,500    382     4,478,900    386      +  4

Colorado  Lake Mead  10,288,500    729.5  10,261,900    732      +2.5
Post-project TDS concentrations are based on an annual Project depletion

of 26,600 acre-feet from the Little Snake River and its tributaries and

an estimated annual Project salt load contribution of 8,960 tons from

irrigation water use.  This amounts to 0.5 tons of salt per acre from

the new lands.  The annual increase in TDS concentrations of 28 mg/1

and 4 mg/1 near Lily, Colorado and Ouray, Utah, respectively, will have

no significant economic impact within and between the Project area and

Lake Mead because:   (1) the quantity of water used in these reaches

is small, and (2) the magnitude of the salinity increase in the range

of mineral quality existing in these reaches of the rivers will have

very little effect on beneficial uses.

      The estimated 2.5 mg/1 increase in the TDS concentration at Lake

Mead resulting from use of Project water will have a detrimental effect

on all Colorado River waterusers below that point.  Data developed by

FWQA's Colorado River Basin Water Quality Control Project indicate

that a 2.5 mg/1 annual increase in the TDS concentration at Lake Mead


will result in an average annual direct equivalent penalty cost—  of

about $109,000 and an average annual indirect equivalent penalty cost

of about $56,600.  These figures are based on a 100-year period of

analysis, beginning in 1970, at 3-1/8 percent interest rate and include

the direct and indirect effects upon agricultural, municipal, and

industrial water users below Hoover Dam.

                 Storage for Streamflow Regulation

      Mineral water quality will be degraded as a consequence of irri-

gation on the Savery-Pot Hook Project.  This degradation will have no

significant economic impact in the Project area or between the Project

area and Lake Mead.  Therefore, no flow regulation for mineral quality

control to protect water uses above Lake Mead is necessary.

      Below Lake Mead, mineral quality deterioration will cause down-

stream water users to suffer an annual economic loss estimated at

$165,600, which clearly indicates the need to incorporate all possible

water quality controls in the Project area or any other area in the

Colorado River Basin.  The large volumes of water stored in both Lakes

Powell and Mead result in the releases from Lake Mead being fairly
I/ A penalty cost is defined as the difference between the detriments
   associated with the use of two different levels of water quality;
   thus, it is based on similar economic conditions which permits the
   cost effect of water quality to be isolated.  Detriments are user
   costs incurred when a specific quality of water is used.


uniform in mineral quality regardless of any seasonal or annual fluc-

tuations in flow and quality of the Colorado River and its tributaries

above the reservoirs.  Therefore,  any regulation of flow achieved by

storage of presently available water in the Project's two reservoirs

(Savery and Pot-Hook) would not change the quality of water discharged

from Hoover Dam.

     In lieu of providing storage in the Project reservoirs for mineral

quality control, salinity control features should be included as part

of the proposed project to mitigate the expected adverse effect of the

project on mineral quality.  These salinity control features should

be installed and operated in the Project area or any other area in

the Colorado River Basin where they are found to be effective and


     Present and projected municipal, industrial and rural organic

waste loads within and below the Project area can be controlled with

adequate treatment at the source.   Therefore, inclusion of separable

storage in Project reservoirs for regulation of streamflow for the pur-

pose of water quality control is not needed.

                       Waste Source Control

     Potential salinity control measures may be divided into two

categories: water-phase and salt-phase.  The former comprises possi-

bilities for improving water quality by augmenting the water supply,

while the latter includes prospects for improving water quality by

reducing the salt input.

     Several water-phase control measures described below appear to

have some technical merit and should be incorporated in the Project.

     CD  Phreatophyte eradication on Project lands and along canals

          and drains could prevent loss of water and make more water


          available for dilution.  It should be recognized, however,

          that phreatophyte eradication may result in loss of wild-

          life habitat and winter protection for cattle and sheep.

     (2)  Better control of the quality of water applied through

          conservation irrigation; the use of irrigation and crop-

          ping methods that best fit a particular soil, slope, crop and

          water supply also offer possibilities for controlling

          mineral quality.

     (3)  Installing closed conveyance systems or lining canals and

          major laterals can result in higher delivery efficiencies

          and consequently improved water quality.  The reduction in

          water loss would prevent unnecessary leaching of salts from

          non-project soils.  Proper land preparation by grading and

          leveling also conserves water.

     Potential salt-phase control measures include the careful

selection of land to be irrigated and the provision of better land

drainage.  Because of the high water table in the Project area, improved

land drainage is especially needed.  Those lands naturally high in

alkaline or sodic salts should be eliminated from consideration in

favor of soils having low natural salt content.  The leaching of

irrigated lands can be assisted by installing subsurface drainage

systems for lands to be newly irrigated on terraces or mesas and

alluvial fans above the river flood plains.  Also protective or cut-

off drains could be provided at the base of the escarpments to prevent

return flows from these higher lands from encroaching on lower flood

plain lands.  With installation of such a drainage system, the salt

load over a number of years may be reduced.  Other measures could in-

clude sealing of saline wells and springs, interception and transport

of highly saline waters to impervious evaporation ponds, and desalting.

Some of these measures are included in the project plan.  Lands naturally

high in alkaline or sodic salts were eliminated from consideration during

normal land classification procedures.  The project plan provides for

the inclusion of drains and the lining of canals and major laterals.

     In order to minimize water quality problems associated with

Project construction activities, the Project contract documents should

contain clauses making it the responsibility of the contractor to comply

with all applicable Federal, state, county and local laws concerning

pollution of rivers and streams.  This would require the contractor to

give careful attention to pollution problems such as disposal of sani-

tary wastes and production of sediment during construction.

     It is anticipated that both Project Reservoirs will provide diversi-

fied recreational opportunities, such as picnicking, camping, fishing

and boating.  Recreational uses expected at the reservoirs are potential

sources of pollution that, if not properly controlled, could create local

water quality problems both in the reservoir and in downstream reaches

of the Little Snake River.  Sanitary waste disposal systems with no

surface effluent discharges will be required at all recreation areas.

In addition, facilities to 'receive and treat the contents of boat waste

holding tanks and containers should be provided at appropriate locations.

Provisions should also be made to require that fuel dispensing equipment

on docks be provided with safety features that will prevent the acci-

dental discharge of petroleum products to the reservoirs.  The essential

features of waste disposal facilities for recreational areas should be

submitted to the Environmental Protection Agency during the early stages

of planning.



1.  Releases and bypasses from Project reservoirs to serve project and

    non-project lands below the Baggs-Dixon area in addition to natural

    flows of the Little Snake River will be adequate to assimilate

    tributary wastes after adequate treatment.  Therefore, inclusion

    of separable storage in the Project reservoirs for regulation of

    stream flow for the purpose of water quality control is not needed.

2.  Irrigation by Project developed water will increase the salinity

    (total dissolved solids) concentration in the Colorado River at

    Lake Mead by 2.5 mg/1.  This increase in salinity will result in

    an estimated average annual total equivalent penalty cost of


3.  Regulation of flow achieved by storage of presently available water

    in Savery and Pot-Hook Reservoirs would not change the mineral

    quality of water discharged from Hoover Dam.

4.  Project construction activities and wastes generated by recreational

    activities may cause water quality degradation in the Project

    reservoirs and the Little Snake River unless adequate water pollution

    control measures are provided.


    To mitigate the potential losses to downstream water users resulting

from the proposed Project, it is recommended that:

1.  The proposed Project be operated in coordination with all other

    Federally-funded water resources projects in the Colorado River

    Basin to meet State-Federal water quality standards.


2.   Additional salinity control features be included as a part of the

    proposed project to mitigate the expected adverse effects of the

    project on water quality.   Some salinity control features are in-

    cluded in the project plan.  Other measures that should be con-

    sidered are the sealing of saline wells and springs, interception

    and transport of highly saline waters to impervious evaporation

    ponds, desalting, and phreatophyte control.  The Project Definite

    Plan should provide for installation and operation of salinity

    control measures in the Project area or any other area in the

    Colorado River Basin where they are found to be effective and


3.   Provisions be included in Project construction specifications to

    assure that appropriate steps are taken by the contractor during

    Project construction to protect the quality of the Little Snake

    River; and

4.   The wastes associated with recreational activities at the proposed

    Savery and Pot-Hook Reservoirs be adequately treated in systems

    that will not discharge treated effluent to the reservoirs.

                References Cited
1.  U.S. Department of the Interior, "Quality of Water,
    Colorado River Basin," Progress Report No. 4,
    January, 1969.

2.  W. V. lorns, C. H. Hembree, and G. L. Oakland, "Water
    Resources of the Upper Colorado River Basin - Technical
    Report," Geological Survey Professional Paper 441, 1965.

3.  W. V. lorns, C. H. Hembree, D. A. Phoenix, and G. L.
    Oakland, "Water Resources of the Upper Colorado River
    Basin-Basic Data," Geological Survey Professional
    Paper 442, 1964.
                                             GPO 836-687