U.S. ENVIRONMENTAL PROTECTION AGENCY
           NATIONAL EUTROPHICATION SURVEY
                    WORKING PAPER SERIES
                                         REPORT
                                           ON
                                      UPPER TWIN LAKE
                                        MONO COUNTY
                                        CALIFORNIA
                                       EPA REGION IX
                                   WORKING PAPER No, 762
 CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
                             and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA

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                                      REPORT
                                        ON
                                  UPPER TWIN LAKE
                                    MONO COUNTY
                                    CALIFORNIA
                                   EPA REGION IX
                              WORKING PAPER No, 762
          WITH THE COOPERATION OF THE
CALIFORNIA STATE WATER RESOURCES CONTROL BOARD
                    AND THE
          CALIFORNIA NATIONAL GUARD   '
                  JUNE, 1978

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                               CONTENTS
                                                        Page
  Foreword                                               ii
  List of California Study Lakes                         iv
  Lake and Drainage Area Map                             v

  Sections
  I.   Conclusions                                        1
 II.   Lake and Drainage Basin Characteristics             3
III.   Lake Water Quality Summary                         4
 IV.   Nutrient Loadings                                  8
  V.   Literature Reviewed                               12
 VI.   Appendices                                        13

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                                ii
                         FOREWORD
    The National Eutrophication Survey was initiated in 1972 in
 response to an Administration commitment to investigate the nation-
 wide threat of accelerated eutrophication to fresh water lakes and
 reservoirs..

 OBJECTIVES

    The Survey was designed to develop, in conjunction with state
 environmental agencies, information on nutrient sources, concentrations,
 and impact on selected freshwater lakes as a basis for formulating
 comprehensive and coordinated national, regional, and state management
 practices relating to point-source discharge reduction and non-point
 source pollution abatement in lake watersheds.

 ANALYTIC APPROACH

    The mathematical and statistical procedures selected for the
 Survey's eutrophication analysis are based on related concepts that:

        a.  A generalized representation or model relating
    sources, concentrations, and impacts can be constructed.

        b.  By applying measurements of relevant parameters
    associated with lake degradation, the generalized model
    can be transformed into an operational  representation of
    a lake, its drainage basin, and related nutrients.

        c.  With such a transformation, an assessment of the
    potential for eutrophication control  can be made.

LAKE ANALYSIS

    In this report, the first stage of evaluation of lake and water-
shed data collected from the study lake and its drainage basin is
documented.   The report is formatted to provide state environmental
agencies with specific information for basin planning [§303(e)], water
quality criteria/standards review [§303(c)], clean lakes [§314(a,b)],
and water quality monitoring [§106 and §305(b)] activities mandated
by the Federal  Water Pollution Control  Act Amendments of 1972.

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                                m
     Beyond the single lake analysis, broader based correlations
between nutrient concentration (and loading) and trophic condi-
tion are being made to advance the rationale and data base for
refinement of nutrient water quality criteria for the Nation's
fresh water lakes.  Likewise, multivariate evaluations for the
relationships between land use, nutrient export, and trophic
condition, by lake class or use, are being developed to assist
in the formulation of planning guidelines and policies by EPA
and to augment plans implementation by the states.

ACKNOWLEDGEMENT

     The staff of the National Eutrophication Survey (Office of
Research & Development, U.S. Environmental Protection Agency)
expresses sincere appreciation to the California State Water
Resources Control Board and the nine Regional Water Quality
Control Boards for professional involvement, to the California
National Guard for conducting the tributary sampling phase of
the Survey, and to those California wastewater treatment plant
operators who voluntarily provided effluent samples and flow
data.

     The staff of the Division of Planning and Research of the
State Water Resources Control Board provided invaluable lake
documentation and counsel during the Survey, coordinated the
reviews of the preliminary reports, and provided critiques
most useful in the preparation of this Working Paper series.

     Major General Glen C. Ames, the Adjutant General  of Cali-
fornia, and Project Officer Second Lieutenant Terry L. Barrie,
who directed the volunteer efforts of the California National
Guardsmen, are also gratefully acknowledged for their assistance
to the Survey.

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                                IV

                   NATIONAL EUTROPHICATION SURVEY

                          STUDY RESERVOIRS
                        State of California
Name

Amador
Boca
Britton
Casitas
Crowl ey
Don Pedro
Elsinore
Fallen Leaf
Hennessey
Henshaw
Iron Gate
Lopez
Mary
Mendocino
Nicasio
Lower Otay
Pillsbury
Santa Margarita
Shasta
Shaver
Silver
Tahoe
Tulloch
Lower Twin
Upper Twin
County

Amador
Nevada
Shasta
Ventura
Mono
Tuolumne
Riverside
El Dorado
Napa
San Diego
Siskiyou
San Luis Obispo
Mono
Mendocino
Marin
San Diego
Lake
San Luis Obispo
Shasta
Fresno
Mono
El Dorado, Placer, CA;
Carson City, Douglas,
Washoe, NV
Calaveras, Tuolumne
Mono
Mono

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  UPPER and LOWER
      TWIN  LAKES
  <8> Tributary Sampling Site
  X Lake Sampling Site
  o Drainage Area Boundary
 0
 I
—     Map Location
3805-
 119 30
                                         11925
                                                                                 11920

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                             UPPER TWIN LAKE
                             STORE! NO. 0625

I.   CONCLUSIONS
    A.   Trophic Condition*:
            Survey data indicate that Upper Twin  Lake  is  early mesotrophic.
        It ranked fifth in overall  trophic  quality  among  the 24  Cali-
        fornia lakes and reservoirs sampled in  1975 when  compared  using
        a combination of six water quality  parameters**.   Seven  of the
        water bodies had less median total  phosphorus,  four had  less
        and two had the same median dissolved orthophosphorus, none
        had less and four had the same median inorganic nitrogen,  eight
        had less mean chlorophyll  a,, and three  had  greater mean  Secchi
        disc transparency.  Essentially no  depression  of  dissolved
        oxygen occurred at depths as great  as 31.4  meters.
            Survey limnologists  observed some submerged macrophytes but
        no surface concentrations of algae. Extensive macrophyte  growths
        are reported to Occur at the west end of  the lake (Bailey, 1977).
            Others have noted that the water quality of Upper Twin
        Lake is good and have assessed the  lake as  oligotrophic
        (Johns, 1975).
    B.   Rate-Limiting Nutrient:
            The algal assay results are not considered  representative
        of conditions in the lake at the times  samples  were taken.
 *  Trophic Assessment is based on levels of nutrients,  dissolved oxygen, and
   chlorophyll a; phytoplankton  kinds and numbers;  and  transparency (Allurn
   et al., 19777.                            .-—
 ** See Appendix A.

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        The lake data indicate  nitrogen  limitation in June and
    Npyemher and phosphorus  limitation in  July.
C.   Nutrient Controllability:
        1.   Point sources—No known wastewater treatment plants
    impacted Upper Twin Lake during the  sampling year.  Septic
    tanks serving Mono Village  and lakeshore dwellings accounted
    for an estimated 1.2%  of the  total phosphorus load, but a
    shoreline survey would have to be conducted to determine the
    actual  inputs from those sources.  However, septic tank failures
    in the past have resulted in  contamination and enrichment
    of the adjacent waters (Johns, 1975).
        The present phosphorus  loading of  0.84 g/m2/year is less
    than that proposed by  Vollenweider (Vollenweider and Dillon,  1974)
    as a eutrophic loading but  is more than his suggested oli-
    gotrophic loading (see page n).  Because the lake is phos-
    phorus limited much of the  time, all phosphorus inputs should
    be minimized to the greatest  practicable extent to protect
    the existing quality of this  water body.
        2.   Non-point sources—Non-point sources accounted for
    98.9% of the total phosphorus input  during the sampling year.
    Robinson Creek contributed  65.9%, and  the ungaged minor tri-
    butaries and immediate drainage contributed an estimated 30.7%.

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II.  LAKE AND DRAINAGE BASIN CHARACTERISTICS1"
    A.  Morphometry"^:
        1.   Surface area:   1.07 kilometers2.
        2.   Mean depth:  14.3 meters.
        3.   Maximum depth:  34.1  meters.
        4.   Volume:  15.301  x 106 m3.
        5.   Mean hydraulic retention time:   136 days.
    B.  Tributary and Outlet:
        (See Appendix C for flow data)
        1.   Tributaries -
                                            Drainage        Mean flow
            Name                            area (km2)*     (m3/sec)*
            Robinson Creek                    54.4            0.889
            Minor tributaries &
             immediate drainage -             20.9            0.414
                        Totals                75.3            1.303
        2.   Outlet -
            Robinson Creek                    76.4**          1.303
    C.  Precipitation***:
        1.   Year of sampling:  8.1 centimeters.
        2.   Mean annual:  14.5 centimeters.
t Table of metric conversions—Appendix B.
tt Uttormark (in press).
* For limits of accuracy, see Working Paper No. 175, "...Survey Methods,
  1973-1976".
** Includes area of lake.
*** See Working Paper No. 175.
                                 \

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III.    WATER QUALITY SUMMARY
    Upper Twin Lake was sampled three times during the open-water season
of 1975 by means of a pontoon-equipped Huey helicopter.   Each time,
samples for physical and chemical parameters were collected from a
number of depths at one station in June and from two stations in July
and November (see map, page v).  During each visit, a single depth-
integrated (4.6 m to surface) sample was composited from the stations
for phytoplankton identification and enumeration; and during the first
and last visits, a single 18.9-liter depth-integrated sample was com-
posited for algal assays.  Also each time, a depth-integrated sample
was collected from each of the stations for chlorophyll  a_ analysis.
The maximum depths sampled were 28.7 meters at station 1 and 31.4
meters at station 2.
    The sampling results are presented in full in Appendix D and are
summarized in the following table.

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PARAMETER


TEMP 


DISS OXY (MG/L)


CNOCTVY IMCROMOI


Prl (STAND UNITS)


TOT ALK (MG/L)


TOT P (MG/L)


ORTHO P (MG/L)


N02+NO3 (MG/D


AMMONIA (MG/D


KJEL N  (MG/L)


INOftfo N (MG/L)


TOTAL N (MG/L)


CHLR^YL A 
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B.   Biological  characteristics:

    1.   Phytoplankton -
        Sampling
        Date
Dominant
Genera
                                Algal  Units
                                per ml	
        06/10/75
1.   Melosira sp.
2.   Stephanodiscus sp.
3.   Tabellaria sp.
4.   Anabaena sp.

                  Total
                                   122
                                    61
                                    61
                                    31

                                   275
        07/01/75
1.  Synedra sp.
2.  Asterionella sp.
3.  Stephanodiscus sp.
4.  Melosira sp.
5.  Chroomonas (?) sp.

                  Total
                                   265
                                   166
                                    33
                                    33
                                    33

                                   530
        11/06/75
1.  Melosira sp.
2.  Cryptomonas sp.
3.  Dlnobryon sp.
                                   231
                                   115
                                    38
                                              Total
                                   384

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    2.   Chlorophyll  a_ -
Sampling
Date
06/10/75
07/01/75
11/06/75
Station
Number
1
2
1
2
1
2
Chlorophyll a
(yg/D
2.5
2.5
3.1
4.5
4.1
C.  Limiting Nutrient Study:
        The algal  assay results are not considered  representative
    of conditions  in the lake at the times  the  samples were  col-
    lected (06/10/75 and 11/06/75)  due  to  significant changes  in
    nutrient concentrations  in the  samples  during shipment from
    the field to the laboratory. However,  the  lake data  indicate
    that nitrogen  was limiting in June  and  November and phosphorus
    was limiting in July; i.e., the mean inorganic  nitrogen/ortho-
    phosphorus ratios were 5/1 in June, 21/1  in July, and 7/1  in
    November.

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                                    8
IV. NUTRIENT LOADINGS
    (See Appendix E for data)
    For the determination of nutrient loadings, the California National
Guard collected monthly near-surface grab samples from each of the
tributary sites indicated on the map (page v), except for the high
runoff months of March and May when two samples were collected.   Sam-
pling was begun in November, 1974, and was completed in September, 1975.
    Through an interagency agreement, stream flow estimates for the
year of sampling and a "normalized" or average year were provided by
the California District Office of the U.S. Geological Survey for the
tributary sites nearest the lake.
    In this report, nutrient loads for sampled tributaries were
calculated using mean annual concentrations and mean annual flows.
Nutrient loads for unsampled "minor tributaries and immediate drainage"
("ZZ" of U.S.G.S.) were estimated using the mean concentrations in
Robinson Creek at station A-2 and the mean annual ZZ flow.
    The nutrient contributions of the Mono Village wastewater treatment
facilities were estimated at 0.1134 kg P and 4.263 kg N/capita/year; and
the contributing population was estimated on the basis of flow (0/3785 m3/
capita/day).
    A.  Waste Sources:
        1.  Known domestic* -
                        Pop.                  Mean flow     Receiving
            Name        Served    Treatment   (m3/day)      Water	
            Mono Village  55      septic tank/   20.74      Upper Twin Lake
                                   leach field
        2.  Known industrial - none
* Pailey, 1977.

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    B.  Annual  Total  Phosphorus Loading - Average Year:
        1.  Inputs -
                                              kg P/         % of
            Source                            yr            total
            a.   Tributaries (non-point load) -
                Robinson Creek                590            65.9
            b.   Minor tributaries & immediate
                 drainage (non-point load) -  275            30.7
            c.   Known domestic STP's -
                    Mono Village                5             0.6
            d.   Septic tanks* -                 5             0.6
            e.   Known industrial - None
            f.   Direct precipitation** -       20             2.2
                        Total                 895           100.0
        2.   Outputs -
            Lake outlet - Robinson Creek       615
        3.   Net annual P accumulation - 280 kg.
* Estimate based on 12 lakeshore dwellings; see Working Paper No. 175.
** See Working Paper No. 175.

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                                   10
    C.  Annual Total Nitrogen Loading - Average Year:
        1.  Inputs -
                                              kg N/         % of
            Source                            yjr	        total
            a.  Tributaries (non-point load) -
                Robinson Creek                21,505         65.1
            b.  Minor tributaries & immediate
                 drainage (non-point load) -  10,015         30.3
            c.  Known domestic STP's -
                    Mono Village                 235          0.7
            d.  Septic tanks*                    130          0.4
            e.  Known industrial - None
            f.  Direct precipitation** -       1.155          3.5
                        Total                  33,040        100.0
        2.  Outputs -
            Lake outlet - Robinson Creek      36,200
        3.  Net annual N loss - 3.160 kg.
    D.  Non-point Nutrient Export by Subdrainage Area:
        Tributary                 kg P/km2/yr   kg N/km2/yr
        Robinson Creek                11            395
* Estimate based on 12 lakeshore dwellings; see Working Paper No.  175.
** See Working Paper No.  175.

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                                   11

    E.  Yearly Loads:
            In the following table,  the existing phosphorus  loadings
        are compared to those proposed by Vollenweider (Vollenweider
        and Dillon, 1974).   Essentially, his "dangerous"  loading  is
        one at which the receiving water would become  eutrophic or
        remain eutrophic; his "permissible"  loading  is that  which
        would result in the receiving  water  remaining  oligotrophic
        or becoming oligotrophic if morphometry permitted.   A meso-
        trophic loading would be considered  one between "dangerous"
        and "permissible".
            Note that Vollenweider's model may not be  applicable  to
        water bodies with short hydraulic retention  times.
                                  Total  Phosphorus       Total Nitrogen
        	Total    Accumulated     Total   Accumulated
        grams/mVyr              0.84      0.26         30.9     loss*
        Vollenweider phosphorus loadings
         (g/m2/yr) based on mean depth and mean
         hydraulic retention time of Upper Twin Lake:
            "Dangerous"  (eutrophic loading)           1.16
            "Permissible"  (oligotrophic loading)      0.58
* There was an apparent loss of nitrogen during the sampling year.   This
  may have been due to nitrogen fixation in the lake,  solubilization of
  previously sedimented nitrogen,  recharge with nitrogen-rich  ground water,
  underestimation of septic tank contributions, or (possibly)  insufficient
  outlet sampling in relation to the hydraulic retention time  of the lake.
  Whatever the cause, a similar nitrogen loss has  occurred at  Shagawa
  Lake, Minnesota, which has been intensively studied  by EPA's former
  National Eutrophication and Lake Restoration Branch  (Malueg  et al., 1975),

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                                   12
V.  LITERATURE REVIEWED

    Allum, M.O., R.E. Glessner, and J.H. Gakstatter, 1977.   An evalua-
        tion of the National  Eutrophication Survey data.   Working Paper
        No. 900, Corvallis Env. Res. Lab., Corvallis, OR.

    Bailey, Thomas E., 1977.   Personal  communication (reviews of pre-
        liminary report).  CA Water Res. Contr.  Bd., Sacramento.

    Johns, Gerald E., 1975.   Personal  communication (water quality
        data).  CA Water Res. Contr. Bd., Sacramento.

    Malueg, Kenneth W., D. Phillips Larsen, Donald W. Schults, and
        Howard T. Mercier; 1975.   A six-year water, phosphorus, and
        nitrogen budget for Shagawa Lake, Minnesota.  Jour.  Environ.
        Qual., vol. 4, no. 2, pp.  236-242.

    Uttormark, Paul D. (in press).   TSI and LCI:  A comparison of
        two lake classification techniques.  North American Project
        Rept., EPA Order No.  P5J11904-J, Corvallis, OR.

    Vollenweider, R.  A., and  P. J.  Dillon, 1974.  The application of
        the phosphorus loading concept to eutrophication  research.
        Natl.  Res. Council of Canada Publ. No.  13690, Canada Centre
        for Inland Waters, Burlington,  Ontario.

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VI.  APPENDICES
                                13
                                   APPENDIX  A
                                  LAKE  RANKINGS

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LAKE DATA TO BE USED IN BANKINGS
LAKE
CODE  LAKE NAME
ObOl  A^ADOW RESERVOIR
0602  BOCA LAKE
0603  LAKE BPITTON
060*  CASITAS RESERVOIR
0605  CPOhLEY LAKE
0606  DON PE9RO RESERVOIR
0607  LAKE ELSINORE
060S  FALLEN LEAF RESERVOIR
0609  LAKE HENNESSEY
0610  LAKE HENSHAW
0611  IRON GATE RESERVOIR
061*  LOPEZ LAKE
0615  LAKE MARY
0616  LAKE MENOOCINO
0617  NICASIO RESERVOIR
0618  LOWER OTAY RESERVOIR
0619  LAKE PILLSBURY
0630  SANTA MARGARITA LAKE
0621  SHASTA LAKE
0622  SHAVER
0623  SILVER LAKE
062<»  TULLOCK RESERVOIR
0625  UPPER TWIN LAKES
0626  LOWER TWIN LAKES
MEDIAN
TOTAL P
0.040
0.012
0.067
0.029
0.046
0.013
0.469
0.007
0.027
0.138
0.184
0.371
0.010
0.020
0.055
0.058
0.022
0.037
0.021
0.014
0.012
0.025
0.015
0.014
MEDIAN
INORG N
0.390
0.040
0.115
0.050
0.045
0.060
0.120
0.040
0.060
0.070
0.690
0.090
0.040
0.050
0.345
0.180
0.060
0.070
0.060
0.060
0.055
0.060
0.040
0.040
500-
MEAN 5EC
408.667
372.833
446.500
400.250
374.750
381.733
489.214
24.357
416.000
461.000
440.333
372.000
296.000
436.500
482.778
447.250
466.667
400.000
381.542
346.400
356.000
433.000
300.200
248.000
MEAN
CHLOKA
22.383
1.700
4.811
3.192
5.800
3.564
70.572
0.786
4.525
26.783
6.217
8.658
2.550
3.100
6.633
15.933
6.389
9.122
4.087
1.700
, 1.800
13.878
3.340
2.900
15-
MIN 00
14.600
6.800
11.200
14.000
12.200
11.400
8.000
8.800
15.000
9.800
13.800
15.000
10.600
9.400
9.800
15.000
8.200
14.800
9.000
7.400
7.000
7.400
7.400
11.400
MEDIAN
DISS OKTHO P
0.020
0.003
0.047
0.014
0.034
0.004
0.092
0.005
0.012
0.073
0.124
0.343
0.002
0.008
0.013
0.013
0.008
0.014
0.015
0.004
0.003
0.009
0.004
0.003

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PERCENT OF LAKES *ITri niGHEH VALUES  CNUMSEK OF LAKES-„• IT* «16HE£ VALUES)
LAKE
CODE  LAKE NAME
0601  AMADOR RESERVOIR
0602  BOCA LAKE
0603  LAKE HPITTON
0604  CASITAS RESERVOIR
0605  CROWLEY LAKE
0606  DON PEDRO RESERVOIR
0607  LAKE ELSINORE
0608  FALLEN LEAF RESERVOIR
0609  LAKE HENNESSEY
0610  LAKE HENSHAW
0611  IRON GATE RESERVOIR
0614  LOPEZ LAKE
0615  LAKE MARY
0616  LAKE MENDOCINO
0617  NICASIO RESERVOIR
0618  LOWER OTAY RESERVOIR
0619  LAKE PILLSBURY
0620  SANTA MARGARITA LAKE
0621  SHASTA LAKE
0622  SHAVER
062J  SILVER LAKE
0624  TULLOCK RESERVOIR
0625  UPPLR TWIN LAKES
0626  LOWER TWIN LAKES
MEDIAN
TOTAL P
35
89 '
17
43
30 i
83 <
0 i
100 i
48 <
13 i
9 I
4 1
96 1
65 <
26 i
22 i
57 1
39 I
61 I
78 1
89 (
52 1
70 I
74 i
( 8)
I 20)
I 4)
( 10)
t 7)
t 19)
I 0)
I 23)
I ID
I 3)
1 2)
t D
( 22)
1 15)
I 6)
t 5)
1 13)
I 9)
I 14)
:' is)
! 20)
I 12)
I 16)
t 17)
MEDIAN
INOWG N
4 1
98 I
22 i
74 i
78 i
54 i
17 I
87 I
54 i
33 I
0 <
26 I
87 I
70 1
9 1
13 <
41 1
33 1
54 1
41 1
65 (
54 (
98 <
87 1
I 1)
I 22)
! 5)
t 17)
t 18)
I 11)
t 4)
1 19)
t 11)
! 7)
I 0)
! 6)
I 19)
I 16)
t 2)
1 3)
t 9)
; 7)
i ID
; 9)
: 15)
ID
I 22)
I 19)
500-
MEAN SEC
43
70
17
48
65
57
0
100
39
13
26
74
91
30
4
22
9
52
61
83
78
35
87
96
( 10)
( 16)
( 4)
< 11)
( 15)
( 13)
( 0)
( 23)
( 9)
( 3)
( 6)
( 17)
( 21)
( 7)
( 1)
( 5)
( 2)
< 12)
( 14)
U 19)
( 18)
( 8)
( 20)
( 22)
MEAN
CHLORA
9
91
48
7C
43
61
0
100
52
4
39
26
83
74
30
13
35
22
57
96
87
17
65
78
( 2)
( 21)
( 11)
( 16)
( 10)
( 14)
( 0)
( 23)
( 12)
( 1)
( 9)
( 6)
( 19)
( 17)
( 7)
( 3)
( 8)
( 5)
( 13)
( 22)
< 20)
( 4)
( 15)
( 18)
15-
MIN DO
17 i
100 I
43 1
22 I
30 I
37 l
78 1
70 1
4 1
54 1
26 1
4 {
48 1
61 1
54 1
4 1
. 74 (
13 1
65 (
87 (
96 (
87 (
87 (
37 (
t 4)
1 23)
I 10)
1 5)
1 7)
I 8)
I 18)
! 16)
I 0)
1 12)
I 6)
I 0)
! 11)
1 14)
I 12)
I 0)
; 17)
: 3)
: is)
19)
22)
19)
19)
8)
MEDIAN
OISS ORTHO P
26
91
17
37
22
78
9
70
52
13
4
0
100
63
46
46
63
37
30
78
91
57
78
91
( (-1
( 20)
( 4)
( 8)
( 5)
( 17)
( 2)
( 16)
( 12)
( 3)
( 1)
( 0)
( 23)
( 14)
( 10)
( 10)
( 14)
( 8)
( 7)
( 17)
( 20)
( 13)
( 17)
( 20)
INDEX
NU
134
539
164
294
268
370
104
527
249
130
104
134
505
363
169
120
279
196
328
463
506
302
485
463

-------
LAKES RANKED BY INDEX NOS.
RANK  LAKE CODE  LAKE NAME               INDEX NO

   I  0602       BOCA LAKE                  539
   2  0608       FALLEN LEAF RESERVOIR      527
   3  0623       SILVER LAKE                506
   4  0615       LAKE MARY                  505
   5  0625       UPPER TWIN LAKES           485
   6  0626       LOWER TWIN LAKES           463
   7  0622       SHAVER                     463
   8  0606       DON PEDRO RESERVOIR        370
   9  0616       LAKE MENDOCINO             363
  10  0621       SHASTA LAKE                326
  11  0624       TULLOCK RESERVOIR          302
  12  0604       CASITAS RESERVOIR          294
  13  0619       LAKE PILLSBURY             279
  14  0605       CROrtLEY LAKE               268
  15  0609       LAKE HENNESSEY             249
      •
  16  0620       SANTA MARGARITA LAKE       196
  17  0617       NICASIO RESERVOIR          169
  18  0603       LAKE BRITTON               164
  19  0614       LOPEZ LAKE                 134
  20  0601       AMADOR RESERVOIR           134
  21  0610       LAKE HENSHArf               130
  22  0618       LOWER OTAY RESERVOIR       120
  23  0607       LAKE ELSINORE              104
  24  0611       IRON GATE RESERVOIR        104

-------
    APPENDIX B





CONVERSION FACTORS

-------
                CONVERSION FACTORS

Hectares x 2.471 = acres
Kilometers x 0.6214 = miles
Meters x 3.281 = feet
Cubic meters x 8.107 x 10    = acre/feet
Square kilometers x 0.3861 = square miles
Cubic meters/sec x 35.315 - cubic feet/sec
Centimeters x 0.3937 = inches
Kilograms x 2.205 = pounds
Kilograms/square kilometer x 5.711  = Ibs/square mile

-------
    APPENDIX C
TRIBUTARY FLOW DATA

-------
                                   TRIBUTARY FLOW INFORMATION FOR CALIFORNIA

LAKE CODE 0625     UPPER TWIN LAKES
                                       09/24/76
0625A1
0625A2
0625ZZ
.INAGE AREA OF LAKE (SO KM)
DRAINAGE
:A(SO KM) JAN
76.4
54.4
20.7
0.21
0.22
0.10
FEB
0.28
0.24
0.11
76.
MAR
0.31
0.31
0.13
4
APR
1.13
0.79
0.26

MAY
2.49
2.21
0.74



NORMALIZED FLOwS(CMS)
JUN JUL AUG
4.67
3.06
1.05
3.82
1.93
0.62
2.41
0.79
0.26

SEP
1.22
0.37
0.14

OCT
0.45
0.24
0.11

NOV
0.16
0.24
0.11

DEC
0.11
0.25
0.11

MEAN
1.303
0.889
0.414
                        TOTAL DRAINAGE AREA OF LAKE =      76.4
                        SUM OF SUB-DRAINAGE AREAS   =      75.1
     MEAN MONTHLY FLOWS AND DAILY FLOWS
-------
        APPENDIX D





PHYSICAL and CHEMICAL DATA

-------
STORET RETRIEVAL DATE 76/09/34

DATE
FROM
TO
75/07/01





75/11/06





DATE
FROM
TO
75/07/01





75/11/06





TIME DEPTH
OF
DAY FEET
13 30 0000
13 30 0005
13 30 0015
13 30 0030
13 30 0050
13 30 0074
14 15 0000
14 15 0005
14 15 0025
14 15 0055
14 15 0094

TIME DEPTH
OF
DAY FEET
13 30 0000
13 30 0005
13 30 0015
13 30 0030
13 30 0050
13 30 0074
14 15 0000
14 15 0005
14 15 0025
14 15 0055
14 15 0094
00010
WATER
TEMP
CENT
10.1
10.3
10.3
10.2
9.3
8.1
10.5
10.6
10.5
10.4
10.3
00665
PHOS-TOT

MG/L P
0.015
0.013
0.014
0.014
0.015
0.029
0.016
0.013
0.018
0.016
0.018
00300
DO

MG/L
8.8
8.6
8.6
8.8
8.4
8.2
8.4
8.4
8.2
7.8
7.8
32217
CHLRPHYL
A
UG/L
2.5





4.5




00077
TRANSP
SECCHI
INCHES
204





228




00031
INCDT LT
REMNING
PERCENT











00094
CNDUCTVY
FIELD
MICROMHO
48
35
35
37
43
42
17
17
17
17
17















                                                                  062501
                                                                 3d  09  10.0  119 21  15.0  3
                                                                 UPPER  TWIN  LAKES
                                                                 06051    CALIFORNIA
                                                                                          150193
                                                                 11EPALES              2111202
                                                                  0078  FEET   DEPTH   CLASS  00
                                                              00400
                                                               PH

                                                               SU
48
35
35
37
43
42
17
17
17
17
17
7.90
7.80
7.80
7.90
7.70
7.60
7.45
7.45
7.45
7.40
7.40
 00410
T ALK
CAC03
 MG/L
 00610
NH3-N
TOTAL
 MG/L
  00625
TOT KJEL
   N
  MG/L
  00630
N02S.N03
N-TOTAL
  MG/L
  00671
PHOS-OIS
 ORTHO
 MG/L P
20
23
26
25
24
22
37
25
22
21
32
0.030
0.020
0.020
0.020K
0.020
0.020
0.020K
0.020K
0.020K
0.020K
0.020K
0.300
0.300
0.200
0.300
0.200
0.200
0.200K
0.200K
0.200K
0.200K
0.200K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.003
0.002K
0.002K
0.002K
0.002
0.002K
0.006
0.004
0.004
0.007
0.004
           K VALUE KNOWN TO BE
           LESS THAN INDICATED

-------
STORET RETRIEVAL DATE 76/09/24
                                                                  062502
                                                                 38 08 52.0 119 21 52.0 3
                                                                 UPPER TWIN LAKES
                                                                 06051   CALIFORNIA
                                                                 11EPALES  751126     2111202
                                                                  0107 FEET  DEPTH  CLASS 00
DATE
FROM
TO
75/06/10





75/07/01





75/11/06




TIME
OF
DAY
12
12
12
12
12
12
13
13
13
13
13
13
13
13
13
13
13

00
00
00
00
00
00
50
50
50
50
50
50
50
50
50
50
50
DEPTH
FEET
0000
0005
0020
0041
0071
0103
0000
0005
0021
0045
0065
0092
0000
0005
0015
0030
0064
00010
WATER
TEMP
CENT

















10.6
10.8
8.0
5.7
4.3
4.1
9.6
9.6
9.5
8.7
7.6
6.7
10.6
10.6
10.6
10.6
10.5
OC665
DATE
FROM
TO
75/06/10





75/07/01





75/11/06




TIME
OF
DAY
12
12
12
12
12
12
13
13
13
13
13
13
13
13
13
13
13


00
00
00
00
00
OP
50
50
50
50
50
50
50
50
50
50
50
DEPTH

FEET
0000
0005
0020
0041
0071
0103
0000
0005
0021
0045
0065
0092
0000
0005
0015
0030
0064
PHOS-TOT


MG/L P
0
0
0
0
0
0
0
0
0
0
0
0
0
0
•:t
0
0
.013
.010
.009
.011
.010
.023
.015
.017
.015
.015
.016
.027
.013
.018
.018
.018
.029
00300
DO
MG/L
8.
9.
9.
9.
8.
7.
8.
8.
8.
8.
8.
7.
7.
8.
8.
8.
7.
32217
00077 00094
TRANSP CNDUCTVY
SECCHI FIELD
INCHES MICROMHO
8 135
0
2
0
2
6
6 204
6
6
6
0
6
8 228
0
4
0
8
00031
35
34
30
35
37
39
32
29
31
32
32
32
17
17
17
17
17

CHLRPHYL INCDT LT
A
UG/L
2.





3.





4.




REMNING
PERCENT
5





1





1























                                                              00400
                                                               PH

                                                               SU
35
34
30
35
37
39
32
29
31
32
32
32
17
17
17
17
17
7.60
7.90
8.10
7.60
7.50
7.90
8.20
7.90
7.80
7.70
7.60
7.40
7.40
7.45
7.40
7.40
7.40
 00410
T ALK
CAC03
 MG/L

     21
     20
     21
     24
     27
     29
     26
     25
     25
     25
     27
     29
     35
     37
     33
     47
     43
00610
NH3-N
TOTAL
MG/L
0.030
0.030
0.030
0.030
0.030
0.040
0.020
0.020K
0.020
0.020
0.020
0.020
0.020K
0.020K
0.020K
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.200*
0.200K
0.200K
0.200K
0.200K
0.200K
0.400
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200K
0.200
0.200K
0.200K
00630
N02&N03
N-TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00671
PHOS-DIS
ORTriO
MG/L P
0.005
0.011
0.012
0.011
0.013
0.014
0.002K
0.002
0.002K
0.002
0.002
0.003
0.007
0.006
0.010
0.007
0.007
            K VALUE KNOWN TO b£
            LESS THAN INDICATED

-------
  APPENDIX E
TRIBUTARY DATA

-------
STORET RETRIEVAL DATE 76/09/24
  DATE   TIME DEPTH N02&N03
  FROM    OF
   TO    DAY  FEET
74/11/15
75/01/15
75/03/14
75/03/15
75/04/27
75/05/12
75/05/30
75/06/06
75/07/07
75/07/24
75/08/04
75/08/15
75/09/11
11 50
10 52
11 30
11 00
09 14
13 00
09 35
09 55
14 35
12 15
14 10
10 50
16 40
                                                                  0625A1
                                                                 38 09 15.0 119 20 55.0 4
                                                                 KOBINSON CHEEK
                                                                 C6      15 MATTERHORN PK
                                                                 0/UPPER TWIN LAKES       150193
                                                                 UNPVO RD bRDG .6 M SW TlrflN LKS CAMPGWND
                                                                 11EPALES             2111204
                                                                  0000 FEET  DEPTH  CLASS 00
i0630
I&N03
OTAL
IG/L
0.008
0.012
0.005
0.008
0.005
0.005
0.015
0.095
0.005
0.015
0.015
0.005
C.005
00625
TOT KJEL
N
MG/L
0.400
0.400
1.700
0.100K
0.150
1.450
2.500
2.500
0.400
0.300
0.050K
0.100
1.200
00610
IMH3-N
TOTAL
MG/L
0.040
0.012
0.045
0.008K
0.010
G.010
0.080
0.080
0.025
0.005
0.005
0.005K
0.315
00671
PHOS-DIS
ORTHO
MG/L P
0.005K
0.005K
0.005K
0.008K
0.005K
0.005K
0.005
0.005K
0.005K
0.010
0.005
0.005K
0.005K
00665
PHOS-TOT

MG/L P
0.010
0.010K
0.010K
0.010K
0.010K

0.020
0.010
0.025
0.010
0.030
0.010K
0.020
    K VALUE KNOWN TO BE
    LESS THAN  INDICATED

-------
STOKET tftTRIEV-AL DATE  76/0-9/24
  DATE   TIME DEPTH N02&N03
  FROM    OF
   TO    DAY  FEET
74/11/15
74/12/13
75/01/15
75/03/14
75/03/15
75/05/12
75/05/30
75/07/07
75/07/24
75/08/04
75/08/15
75/09/11
11 10
10 00
10 30
11 15
10 45
12 45
09 30
14 05
13 50
13 55
11 10
16 10
                                                                   062SA2
                                                                  33 08 45.0 119 22 30.0 4
                                                                  HfOBINSON CREEK
                                                                  06      is MATTERHORN PK
                                                                  T/UPPER TWIN LAKES       150193
                                                                  tJNK .5 MI S OF MONO VILLAGE
                                                                  I1EPALES             2111204
                                                                   0000 FEET  DEPTH  CLASS 00
0630
&N03
OTAL
G/L
0.02^
0.0^8
0.072
0.055
0.056
0.030
0.020
0.020
0.020
0.020
0.005
0.030
00625
TOT KJEL
N
MG/L
0.100
0.400
0.400
0.300
0.100K
0.700
1.500
3.700
0.050
0.050
0.800
0.700
00610
NH3-N
TOTAL
MG/L
0.020
0.015
0.016
0.030
0.008K
0.005
0.025
0.135
0.005K
0.010
0.010
0.210
00671
PHOS-DIS
ORTHO
MG/L P
0.005K
0.006
0.005K
0.005K
0.008K
0.005
0.005
0.005
0.010
0.005
0.005K
0.005K
006t>5
PMOS-TOT

MG/L P
0.0?0
0.020
0.010K
0.010K
0.010*
0.040
0.020
0.020
0.010
0.040
0.020
0.030
     K VALUE KNOWN TO BE
     LESS THAN INDICATED

-------