U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
LOWER WIN U\KE
MONO COUNTY
CALIFORNIA
EPA REGION IX
WORKING PAPER No, 751
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
-------
REPORT
ON
LOWER TWIN LAKE
1TO COUNTY
CALIFORNIA
EPA REGION IX
WORKING PAPER No, 761
WITH THE COOPERATION OF THE
CALIFORNIA STATE WATER RESOURCES CONTROL BOARD
AND THE
CALIFORNIA NATIONAL GUARD
JUNE, 1978
-------
1
CONTENTS
Page
Foreword i i
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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E o. B. £ w. Q. ft D.
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)j activities mandated
by the Federal Water Pollution Control Act Amendments of 1972.
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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
Crowley
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
® Tributary Sampling Site
X Lake Sampling Site
^» Drainage Area Boundary
1 2 3 4Km.
Scale
2 Mi.
Map Location
3805-
119 30
11925
11920
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LOWER TWIN LAKE
STORE! NO. 0626
I. CONCLUSIONS
A. Trophic Condidion*:
Survey data indicate that Lower Twin Lake is early meso-
trophic. It ranked sixth in overall trophic quality among
the 24 California lakes and reservoirs sampled in 1975 when
compared using a combination of six water quality parameters**.
Five of the water bodies had less and one had the same median
total phosphorus, one had less and two had the same median
dissolved orthophosphorus, none had less but four had the same
median inorganic nitrogen, five had less mean chlorophyll a_,
and one had greater mean Secchi disc transparency. Moderate
depression of dissolved oxygen with depth occurred at station 1
in July (3.6 mg/1 at 27.4 meters).
Survey limnologists did not observe macrophytes or surface
concentrations of algae.
Others indicate the quality of the lake is good and
assess it 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 collected
(03/19/75 and 11/06/75). The lake data indicate nitrogen
limitation in March and phosphorus limitation in July and November.
* Trophic assessment is based on levels of nutrients, dissolved oxygen, and
chlorophyll a; phytoplankton kinds and numbers; and transparency (Allurn
et al., 19771.
** See Appendix A.
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C. Nutrient Controllability:
1. Point sources—No known wastewater treatment plants
impacted the lake during the sampling year. Septic tanks
serving lakeshore dwellings accounted for an estimated 1.2%
of the total phosphorus input, and septic tank contributions
to Upper Twin Lake* may add nutrients to this lake; however
shoreline surveys would have to be done to determine the signi-
ficance of those sources. Failure of septic tank systems around
the lake in the past has resulted in contamination and enrichment
of the adjacent waters (Johns, 1975).
The present phosphorus loading of 0.55 g/mz/year is about
that proposed by Vollenweider (Vollenweider and Dillon, 1974)
as an oligotrophic loading (see page 11). Because the water
body is phosphorus limited much of the time, all phosphorus
loads should be minimized to protect the present water quality.
2. Non-point sources--Non-point sources accounted for 98.8%
of the total phosphorus load during the sampling year. Robin-
son Creek contributed 73.6%, and the ungaged minor tributaries
and immediate drainage contributed an estimated 22.2% of the
total load.
Working Paper No. 762
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II. LAKE AND DRAINAGE BASIN CHARACTERISTICS1"
A. Morphometry1'1':
1. Surface area: 1.52 kilometers2.
2. Mean depth: 15.2 meters.
3. Maximum depth: 45.4 meters.
4. Volume: 23.104 x 106 m3.
5. Mean hydraulic retention time: 157 days.
B. Tributary and Outlet:
(See Appendix C for flow data)
1. Tributaries -
Drainage Mean flow
Name area (km2)* (m3/sec)*
Robinson Creek 76.4 1.303
Minor tributaries &
immediate drainage - 23.4 0.396
Totals 99.8 1.699
2. Outlet -
Robinson Creek 101.3** 1.699
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. LAKE WATER QUALITY SUMMARY
Lower 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 March and 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 39.6 meters at station 1 and 37.8
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
OISS OXY (MG/L)
CNDCTVY (MCROMO)
PH (STAND UNITS)
TOT ALK (MG/L)
TOT P (MG/D
ORTHO P (MG/L)
N02»N03 (MG/L)
AMMONIA (MG/L)
KJEL N (MG/L)
INORG N (MG/L)
TOTAL N (MG/L)
CHLRPVL A
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B. Biological characteristics:
1. Phytoplankton -
Sampling
Date
03/19/75
Dominant
Genera
1. Chroomonas (?) sp.
2. Melosira sjp_.
3. Synedra sp.
4. Stephanodiscus sp.
5. Asterionella sp.
Other genera
Total
Algal Units
per ml
275
78
78
39
39
40
549
07/01/75
1. Melosira sp.
2. Cryptomonas sp.
3. Stephanodiscus sjj.
4. Synedra sp.
5. Fragilaria SJD.
Total
81
33
16
16
16
162
11/06/75
1. Fragilaria sp.
2. Cryptomonas sp.
3. Chroomonas (T) sp.
4. Tabellaria sp.
72
72
72
36
Total
252
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2. Chlorophyll a^ -
Sampling
Date
03/19/75
07/01/75
11/06/75
Station
Number
1
2
1
2
1
2
Chlorophyll a^
(yg/D
3.0
1.7
1.5
4.3
4.0
C. Limiting Nutrient Study:
Due to significant changes in nutrients in the samples during
shipment from the field to the laboratory, the algal assay re-
sults are not considered representative of conditions in the
lake at the time samples were collected (03/19/75 and 11/06/75).
The lake data indicate nitrogen limitation in March and phos-
phorus limitation in July and November. The mean inorganic
nitrogen/orthophosphorus ratios were 11/1 in March, 15/1 in
July, and 18/1 in November. Nitrogen limitation would be ex-
pected when N/P ratios are less than 14/1.
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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 May and July when two samples were collected.
Sampling 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 25A-1/26A-2 and the mean annual ZZ flow.
No known wastewater treatment plants impacted the lake during the
sampling year.
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A. Waste Sources:
1. Known municipal - None
2. Known industrial - None
B. Annual Total Phosphorus Loading - Average Year:
1. Inputs -
kg P/ % of
Source yr total
a. Tributaries (non-point load) -
Robinson Creek 615 73.6
b. Minor tributaries & immediate
drainage (non-point load) - 185 22.2
c. Known municipal STP's - None
d. Septic tanks* - 10 1.2
e. Known industrial - None
f. Direct precipitation**- 25 3.0
Total 835 100.0
2. Outputs -
Lake outlet - Robinson Creek 695
3. Net annual P accumulation - 140 kg.
* Estimate based on 27 lakeshore dwellings and one campground; 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 yj; total
a. Tributaries (non-point load) -
Robinson Creek 36,200 73.6
b. Minor tributaries & immediate
drainage (non-point load) - 11,000 22.4
c. Known municipal STP's - None
d. Septic tanks*- 360 0.7
e. Known industrial - None
f. Direct precipitation** - 1,640 3.3
Total 49,200 100.0
2. Outputs -
Lake outlet - Robinson Creek 51,060
3. Net annual N loss - 1,860 kg.
D. Non-point Nutrient Export by Subdrainage Area:
Tributary kg P/km2/yr kg N/km2/yr
Robinson Creek 8 474
E. Mean Nutrient Concentrations in Ungaged Stream:
Mean Total P Mean Total N
Tributary Cone, (rng/1) Cone, (mg/1)
Unnamed Creek B-l 0.018 1.142
* Estimate based on 27 lakeshore dwellings and one campground; see Working
Paper No. 175.
** See Working Paper No. 175.
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1.1
F. 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/m2/yr 0.55 0.09 32.4 loss*
Vollenweider phosphorus loadings
(g/m2/yr) based on mean depth and mean
hydraulic retention time of Lower Twin Lake:
"Dangerous" (eutrophic loading) 1.12
"Permissible" (oligotrophic loading) 0.56
* 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.
Chun, Robert U. D., 1973. Mammoth Basin water resources environ-
mental study. CA Dept. of Water Res., Southern Dist., Sacra-
mento.
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 Proj.
Rept., EPA Order No. P3J11904-J, Corvallis, OR.
Vollenweider, R. A., and P. J. Dillon, 1974. The application of
the phosphorus loading concept to eutrophication research.
Nat!. Res. Council of Canada Publ. No. 13690, Canada Centre
for Inland Waters, Burlington, Ontario.
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VI. APPENDICES
APPENDIX A
LAKE RANKINGS
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LAKE DATA TO rtE USED IN RANKINGS
LAKE
COOE LAKE NAME
0601 AMADOH RESERVOIR
0603 80CA LAKE
0603 LAKE BPITTON
060* CASITAS RESERVOIR
060-5 CPOhLEY LAKE
0606 DON PEORO RESERVOIR
0607 LAKE ELSINORE
0608 FALLEN LEAF RESERVOIR
0609 LAKE HENNESSEY
0610 LAKE HENSHAW
06ii IRON GATE RESERVOIR
0614 LOPEZ LAKE
0615 LAKE MARY
0616 LAKE MENDOCINO
0617 NICASIO RESERVOIR
0618 LOWER OTAY RESERVOIR
0619 LAKE PILLS8URY
0630 SANTA MARGARITA LAKE
0631 SHASTA LAKE
0633 SHAVER
0633 SILVER LAKE
0634 TULLOCK RESERVOIR
0635 UPPER TWIN LAKES
0636 LOWER TWIN LAKES
MEDIAN
TOTAL P
0.040
0.013
0.067
0.039
0.046
0.013
0.469
0.007
0.037
0.138
0.184
0.371
0.010
0.030
0.055
0.058
0.022
0.037
0.021
0.014
0.013
0.035
0.015
0.014
MEDIAN
INORG !M
0.390
0.040
0.115
0.050
0.045
0.060
0.130
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
44d.500
400.250
374.750
381.733
489.214
24.357
416.000
461.000
440 . 333
372.000
396.000
436.500
482.778
447.250
466.667
400.000
381.542
346.400
356.000
433.000
300.200
248.000
MEAN
22.383
1.700
4.811
3.192
5.800
3.564
70.573
0.786
4.535
36.783
6.317
8.658
3.550
3.100
6.633
15.933
6.389
9.133
4.087
1.700
1.800
13.878
3.340
3.900
15-
MIN 00
14.600
6.800
11.300
14.000
13.300
11.400
8.000
8.800
15.000
9.800
13.800
15.000
10.600
9.400
9.800
15.000
0.200
14. BOO
9.000
7.400
7.000
7.400
7.400
11.400
MEDIAN
OISS OHTHO P
0.030
0.003
0.047
0.014
0.034
0.004
0.093
0.005
0.013
0.073
0.134
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 LftKES WlTrl rllGHEH VALUES (NUMBER Or LAKES *TTn"HIGHEH VALUES/-
LAKE
CODE LAKE NAME
ObOl AMAOOR RESERVOIR
0602 BOCA LAKE
0603 LAKE tiPITTON
060* CASITAS RESERVOIR
0605 CROWLEY LAKE
0606 DON PEO»0 RESERVOIR
0607 LAKE ELSINORE
0608 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
0620 SANTA MARGARITA LAKE
0621 SHASTA LAKE
0622 SHAVER
062J SILVER LAKE
062* TULLOCK RESERVOIR
0625 UPPtR TWIN LAKES
0626 LOWER TWIN LAKES
MEDIAN
TOTAL P
35
89
17
43
30
83
0
100
48
13
9
4
96
65
26
22
57
39
61
78
89
52
70
74
( 8)
( 20)
< 4)
( 10)
( 7)
( 19)
( 0)
( 23)
< 11)
( 3)
( 2)
( 1)
( 22)
( 15)
( 6)
( 5)
< 13)
( 9)
( 14)
( 18)
(20)
( 12)
( 16)
( 17)
MEDIAN
iNORG N
4
98
22
74
78
54
17
87
54
33
0
26
87
70
9
13
41
33
54
41
65
54
98
87
( 1)
( 22)
( 5)
( 17)
( 18)
( 11)
( 4)
( 19)
( ID
( 7)
( 0)
( 6)
( 19)
( 16)
< 2)
( 3)
( 9)
< 7)
( 11)
( 9)
( 15)
( 11)
( 22)
( 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)
t 21)
( 7)
( 1)
( 5)
( 2)
( 12)
( 14)
(. 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)
( ID
( 16)
( 10)
( 1«>
( 0)
( 23>
( 12)
( 1)
( 9)
( 6)
( 19)
( 17)
( 7)
( 3)
( 8)
( 5)
( 13)
( 22)
( 20)
( 4)
( 15)
( 18)
15-
MIN DO
17 (
100 (
43 (
22 (
30 (
37 (
78 (
70 (
4 (
54 (
26 (
4 (
48 (
61 (
54 (
4 (
. 74 (
13 (
65 (
87 (
96 (
87 (
87 (
37 (
4)
23)
10)
5)
7)
8)
18)
16)
0)
12)
6)
0)
11)
14)
12)
0)
17)
3)
15)
19)
22)
19)
19)
8)
MEDIAN
DISS 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
( 6)
( 20)
( 4)
< 8)
( 5)
( 17) .
( 2)
( 16)
( 12)
( 3)
( 1)
( 0)
( 23)
( 14)
( 10)
( 10)
( 14)
( 8)
( 7)
( 17)
( 20)
( 13)
( 17)
( 20)
INDEX
NO
134
539
164
294
268
370
104
527
249
130
104
134
505
363
169
120
279
196
328
463
506
302
485
463
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LAKES RANKED BY INDEX NOS.
RANK LAKE CODE LAKE NAME INDEX NO
1 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 328
11 0624 TULLOCK RESERVOIR 302
12 0604 CASITAS RESERVOIR 294
13 0619 LAKE PILLSBURY 279
14 0605 CROWLEY LAKE 268
15 0609 LAKE HENNESSEY 249
16 0620 SANTA MARGARITA LAKE 196
17 0617 NICASIO RESERVOIR 169
18 0603 LAKE 6RITTON 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
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APPENDIX B
CONVERSION FACTORS
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CONVERSION FACTORS
Hectares x 2.471 = acres
Kilometers x 0.6214 = miles
Meters x 3.281 = feet
Cubic meters x 8.107 x 10 ~4 = 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
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APPENDIX C
TRIBUTARY FLOW DATA
-------
TRIBUTARY FLOW INFORMATION FOR CALIFORNIA
09/24/76
LAKE CODE 0626
LOWER TWIN LAKES
TOTAL OPAINAGE AREA OF LAKE(SQ KM)
SUB-DRAINAGE
101.3
TRIBUTARY APEA(SQ KM)
0626A1
0626A2
0626ZZ
101.3
76.4
23.1
JAN
0.23
0.21
0.12
FEB
0.39
0.28
0.13
MAR
0.41
0.31
0.15
APR
1.39
1.13
0.31
TOTAL DRAINAGE AREA OF LAKE
SUM OF SUB-DRAINAGE AREAS
MAY
2.89
2.49
0.88
101.3
99.5
NORMALIZED FLOWS(CMS)
JUN JUL AUG
MEAN MONTHLY FLOWS AND DAILY FLOWS(CMS)
TRIBUTARY MONTH YEAR MEAN FLOW DAY FLOW DAY
0626A1
0626A2
0626ZZ
11
12
1
2
3
4
5
6
7
8
9
10
11
12
1
?
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
74
74
75
75
75
75
75
75
75
75
75
75
74
74
75
75
75
75
75
75
75
75
75
75
74
74
75
75
75
75
75
75
75
75
75
75
0.152
0.025
0.014
0.023
0.182
0.631
2.798
6.9P4
5.069
2.917
2.263
0.654
0.255
0.008
0.057
0.425
0.453
0.396
2.124
5.607
4.078
1.529
1.557
0.566
0.133
0.122
0.113
0.116
0.130
0.142
0.878
1.586
0.906
0.311
0.204
0.0
15
13
15
14
27
12
6
7
4
11
15
13
15
14
27
12
6
7
4
11
0.215
0.024
0.013
0.018
0.510
2.322
8.014
5.607
2.379
2.350
0.396
0.023
0.045
0.396
0.368
1.048
6.768
4.842
1.699
1.812
15
29
30
24
15
15
30
24
15
5.24
4.67
1.25
4.45
3.82
0.74
2.79
2.41
0.31
SEP
1.46
1.22
0.17
OCT
0.58
0.45
0.13
NOV
0.22
0.16
0.13
DEC
0.14
0.11
0.14
MEAN
1-699
1«303
0. 396
SUMMARY
TOTAL FLOW IN
TOTAL FLOW OUT
21.73
20.24
FLOW DAY
0.023
1.671
4.332
4.304
2.860
FLOW
0.396
4.049
3.341
1.642
-------
APPENDIX D
PHYSICAL and CHEMICAL DATA
-------
STORET RETRIEVAL DATE 76/09/24
DATE
FROM
TO
75/03/19
75/07/01
75/11/06
TIME DEPTH
OF
DAY FEET
10 45 0000
10 45 0005
10 45 0030
10 45 0060
10 45 0090
10 45 0110
12 00 0000
12 00 0005
12 00 0015
12 00 0035
12 00 0060
12 00 0090
12 00 0130
13 25 0000
13 ?5 0005
13 25 0015
13 25 0033
13 25 0070
13 25 0110
00010
WATER
TEMP
CENT
2.6
2.6
2.6
2.6
2.6
2.7
12.5
12.5
12.1
11.9
9.9
6.7
5.9
10.6
10.6
10.5
10.4
10.4
00300
DO
MG/L
10.0
10.0
9.8
10.0
9.9
10.0
8.2
8.2
8.2
H.2
8.4
3.6
6.6
8.0
7.6
7.6
7.4
7.8
8.8
00077 00094
TRANSP CNDOC
SECCHI FIELD
INCHES MICRO
312
240
228
062601
38 09 30.0 119 20 25.0 3
LOWER TWIN. LAKES
06051 CALIFORNIA
150193
11EPALES
Oil* FEET
2111202
DEPTH CLASS 00
'4
VY
HO
18
20
20
20
20
20
53
45
43
31
44
42
50
21
23
23
23
23
00400
PH
SU
6.50
6.80
6.80
7.00
7.20
7.20
7.90
8.40
8.10
7.90
7.75
7.60
7.40
8.90
8.50
8.30
8.20
7.95
7.90
00410
T ALK
CAC03
MG/L
26
26
25
24
25
28
33
31
31
23
25
27
31
19
22
25
25
23
25
00610
NH3-N
TOTAL
MG/L
0.030
0.020
0.020K
0.020
0.020K
0.030
0.030
0.020
0.030
0.020
0.020
0.020
0.040
0.020K
0.080
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.200
0.200K
0.200K
0.200K
0.200
0.300
0.200
0.200
0.200K
0.200
0.200
0.200
0.200
0.200K
0.200K
0.200K
0.200K
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
0.02UK
0.020K
0.020K
0.020
0.030
00671
PHOS-DIS
ORTHO
MG/L P
0.004
0.003
0.002
0.003
0.002
0.008
0.004
0.003
0.003
0.002
0.003
0.003
0.006
0.002
0.002K
0.002
0.002K
0.002
0.003
K VALUE KNOWN TO BE
LESS THAN INDICATED
-------
STORE! RETRIEVAL BATE 76/09/34
062601
38 09 30.0 119 20 25.0 3
LOWE" TWIN LAKES
06051 CALIFORNIA
150193
11EPALES
0114 FEET
2111202
DEPTH CLASS 00
00665 32217 00031
DATE TIME DEPTH PHOS-TOT CHLRPHYL INCDT LT
FROM OF A REMNING
TO DAY FEET MG/L P UG/L PERCENT
3.0
1.7
75/03/19
75/07/01
75/11/06
10
10
10
10
10
10
12
12
12
12
12
12
12
13
13
13
13
13
13
45
45
45
45
45
45
00
00
00
00
00
00
00
25
25
?5
25
25
25
0000
0005
0030
0060
0090
0110
0000
0005
0015
0035
0060
0090
0130
0000
0005
0015
0033
0070
0110
0.011
0.010
0.011
0.010
0.011
0.013
0.017
0.016
0.015
0.017
0.018
0.015
0.028
0.014
0.012
0.009
0.011
0.016
0.016
4.3
-------
STORET RETRIEVAL DATE 76/09/34
DATE
FROM
TO
75/07/01
75/11/06
TIME DEPTH
OF
DAY FEET
12 30 0000
12 30 0005
12 30 0015
12 30 0035
12 30 0060
12 30 0085
12 30 0110
13 05 0000
13 05 0005
13 05 0015
13 05 0035
13 05 0075
13 05 0124
00010
WATER
TEMP
CENT
12.4
12.5
12.4
12.1
8.3
6.2
6.0
10.6
10.6
10.6
10.5
10.1
10.3
062602
3B 10 OC.O 119 19 47.0 3
LOWER THIN LAKES
06051 CALIFORNIA
150193
11EPALES
0115 FEET
2111202
DEPTH CLASS 00
00010
WATER
TEMP
CENT
00300
00
MG/L
00077
TRANSP
SECCHI
INCHES
00094
CNDUCTVY
FIELD
MICROMHO
00400
PH
SU
00410
T ALK
CAC03
MG/L
00610
NH3-N
TOTAL
MG/L
00625
TOT KJEL
N
MG/L
00630
N02&N03
N-TOTAL
MG/L
00671
PHOS-DIS
ORTrtO
MG/L P
8.6
8.6
8.4
8.2
8.0
7.8
7.2
8.2
7.8
7.6
7.6
6.8
5.8
240
240
44
45
39
40
41
42
42
25
23
23
23
24
25
7.90
8.60
8.20
8.05
7.80
7.60
7.40
7.80
7.70
7.70
7.60
7.50
7.45
26
28
27
27
29
32
32
34
25
24
30
20
22
0.020
0.030
0.020
0.020
0.020
0.030
0.030
0.020K
0.300
0.300
0.200
0.200
0.200
0.200
0.300
0.300
0.200K
0.200K
0.200
0.200K
0.200K
0.020K
0.020K.
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020
0.020
0.040
0.004
0.003
0.002
0.002K
0.002
0.003
0.005
0.004
0.002
0.004
o.ooa
0.002
0.005
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/07/01 12 30 0000
12 30 0005
12 30 0015
12 30 0035
12 30 0060
12 30 OOB5
12 30 0110
75/11/06 13 05 0000
13 05 0005
13 05 0015
13 05 0035
13 05 0075
13 05 0124
0665
S-TOT
/L P
0.01S
0.014
0.013
3.015
0.013
0.015
0.017
0.019
0.016
0.014
0.012
0.011
0.015
32217 00031
CHLRPHYL INCDT LT
A REMNING
UG/L PERCENT
1.5
4.0
K VALUE KNOWN TO dE
LESS THAN INDICATED
-------
APPENDIX E
TRIBUTARY DATA
-------
STORET RETRIEVAL DATE 76/09/24
0626A1
38 10 20.0 119 19 25.0 4
ROBINSON CREEK
06 15 MATTERHORN PK
0/LO«E» TWIN LAKES 150193
SEC SO BtfOG .1 Ml N OF T«*IN LKS CAMPGHND
HEPALES 2111204
0000 FEET DEPTH CLASS 00
DATE
FROM
TO
74/11/15
74/12/13
75/01/15
75/03/14
75/03/15
75/04/29
75/05/12
75/05/30
75/06/06
75/07/07
75/07/24
75/08/04
75/08/15
75/09/11
TIME i
OF
DAY 1
12 40
10 ?5
11 15
12 05
11 45
08 30
13 35
10 15
10 30
15 10
11 00
14 41
10 35
17 50
FEET
00630
N02&N03
N-TOTAL
MG/L
0.008
0.032
0.040
0.020
0.024
0.070
0.005
0.010
0.070
0.005
0.025
0.005
0.020
0.005
00625
TOT KJEL
N
MG/L
0.100
0.400
0.650
2.100
0.200
0.650
1.350
2.100
0.800
0.300
3.150
0.300
0.300
0.600
00610
NH3-N
TOTAL
MG/L
0.025
0.015
0.016
0.035
0.008K
0.035
0.010
0.090
0.050
0.040
0.085
0.017
0.020
0.035 •
00671
PHOS-OIS
ORTHO
MG/L P
0.005K
0.005
0.005K
0.005
0.008K
0.005K
0.005K
0.005K
0.005K
0.005K
0.015
0.005K
0.005K
0.005K
00665
PHOS-TOT
MG/L P
0.020
0.010K
0.010K
0.010K
0.010K
0.010K
0.010
0.020
0.020
0.015
0.010
0.020
0.010
K VALUE KMOWN TO 8E
LESS THAN INDICATED
-------
STORET RETRIEVAL DATE 76/09/3*
0626A2
38 09 15.0 119 20 55.0 4
ROBINSON CREEK
06 15 MATTERHORN PK
T/LOWErt TWIN LAKES 150193
UNPVD KD bRDG 1.5 MI E OF MONO VILLAGE
11EPALES 2111204
0000 FEET DEPTH CLASS 00
DATE
FROM
TO
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
TIME
OF
DAY
11 50
10 50
11 30
11 00
09 12
13 10
09 35
OQ 45
14 52
10 30
13 45
10 50
16 30
FEET
00630
N02&N03
N-TOTAL
MG/L
(J.005K
0.012
0.005
0.008
0.010
0.010
0.010
0.050
0.005
0.005
0.005
0.005
0.005
00625
TOT KJEL
N
MG/L
0.100K
1.300
1.280
0.500
1.000
0.800
2.500
0.150
0.050K
0.200
0.350
0.400
00610
NH3-N
TOTAL
MG/L
0.008
0.016
0.025
0.008K
0.020
0.010
0.090
0.010
0.080
0.010
0.010
0.020
0.030
00671
PHOS-DIS
ORTHO
MG/L P
0.005
0.005K
0.005K
C.008K
0.005K
0.005K
0.005K
0.005K
0.005K
0.010
0.005K
0.005K
0.005K
00665
PHOS-TOT
MG/L P
0.025
0.010K
0.010K
0.010K
0.010K
0.020
U.010K
0.020
0.010
0.010K
C.020
0.020
K VALUE KI^OWN TO B£
LESS THAN INDICATED
-------
STORE! RETRIEVAL DATE 76/09/24
DATE TIME DEPTH N024N03
FROM or
TO DAY FEET
74/11/15 12 ?0
75/05/30 09 59
75/06/06 10 10
75/07/07 1* 30
75/07/?4 13 48
75/08/04 11 25
75/08/15 11 00
75/09/U 16 SO
0626B1
38 09 15.0 119 20 30.0 4
UNNAMED CREEK
06 15 MATTERHORN PK
T/LOWtW TWIN LAKES 150193
SEC *D BROG 1.5 MI SW TWIN LKS CAMPGRND
11EPALES 2111204
0000 FEET DEPTH CLASS 00
0630
4N03
OTAL
G/L
0.008
0.005
0.075
0.005
0.005
0.005
0.010
0.020
00625
TOT KJEL
N
MG/L
0.1CO
1.150
2.300
0.100
0.100
0.050
4.200
1.000
00610
NH3-N
TOTAL
MG/L
0.015
0.050
0.260
0.015
0.005
0.005K
0.850
0.025
00671
PHOS-DIS
ORTHO
MG/L P
0.020
0.005K
0.005K
0.0.05
0.010
0.005
0.005K
0.005K
00665
PHOS-TOT
MG/L P
0.040
0.010K
0.020
0.010
0.010
0.010
0.015
0.030
K VALUE KNOWN TO BE
LESS THAN INDICATED
------- |