U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
TRINIDAD LAKE
HENDERSON COUNTY
TEXAS
EPA REGION VI
WORKING PAPER No, 665
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
699-440
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REPORT
ON
TRINIDAD LAKE
HENDERSON COUNTY
TEXAS
EPA REGION VI
WORKING PAPER No, 665
WITH THE COOPERATION OF THE
TEXAS WATER QUALITY BOARD
AND THE
TEXAS NATIONAL GUARD
MARCH, 1977
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i
CONTENTS
Page
Foreward ii
List of Texas Study Reservoirs iv
Lake and Drainage Area Map vi
Sections
I. Introduction 1
II. Conclusions 1
III. Lake and Drainage Basin Characteristics 3
IV. Lake Water Quality Summary 4
V. Literature Reviewed 10
VI. Appendices 11
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n
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 freshwater 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)J, 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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Ill
Beyond the single lake analysis, broader based correlations
between nutrient concentrations (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 Texas Water Quality Board
for professional involvement, to the Texas National Guard for
conducting the tributary sampling phase of the Survey, and to
those Texas wastewater treatment plant operators who voluntarily
provided effluent samples.
Hugh C. Yantis, Jr., Executive Director of the Texas Water
Quality Board, and John B. Latchford, Jr., Director, and the staff
of the Field Operations Division provided invaluable lake documen-
tation and counsel during the Survey, reviewed the preliminary
reports, and provided critiques most useful in the preparation of
this Working Paper series.
Major General Thomas Bishop, the Adjutant General of Texas,
and Project Officer Colonel William L. Seals, who directed the
volunteer efforts of the Texas National Guardsmen, are also grate-
fully acknowledged for their assistance to the Survey.
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1v
NATIONAL EUTROPHICATION SURVEY
STUDY RESERVOIRS
State of Texas
NAME
Amistad
Bastrop
Bel ton
Braunig
Brownwood
Buchanan
Caddo
f
Calaveras
Canyon
Colorado City
Corpus Christ!
Diversion
Eagle Mountain
Fort Phantom Hill
Houston
Kemp
Lake O'The Pines
Lavon
Lewisville (Garza-Little Elm)
Livingston
COUNTY
Val Verde
Bastrop
Bell, Coryell
Bexar
Brown
Burnet, Llano
Harrison, Marion, TX;
Caddo Parish, LA
Bexar
Comal
Mitchell
Jim Wells, Live Oak, San
Patricio
Archer, Baylor
Tarrant, Wise
Jones
Harris
Baylor
Camp, Marion, Morris,
Upshur
Coll in
Denton
Polk, San Jacinto, Trinity,
Walker
-------
Lyndon B. Johnson
Medina
Meredith
0. C. Fisher (San Angelo)
Palestine
Possum Kingdom
Sam Rayburn
Somerville
E. V. Spence
Stamford
Still house Hollow
Tawakoni
Texoma
Travis
Trinidad
Twin Buttes
White River
Whitney
Wright Patman (Texarkana)
Burnet, Llano
Bandera, Medina
Hutchinson, Moore,
Potter
Tom Green
Anderson, Cherokee,
Henderson, Smith
Palo Pinto, Stephens,
Young
Angelina, Jasper
Nacogdoches, Sabine, San
Augustine
Burleson, Lee, Washington
Coke
Haskell
Bell
Hunt, Rains, Van Zandt
Cooke, Grayson TX; Bryan,
Johnston, Love, Marshall, OK
Burnet, Travis
Henderson
Tom Green
Crosby
Bosque, Hill
Bowie, Cass
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vi
TRWtDAD LAK£
TRINIDAD LAKE
X Lake Sampling Site
Vz 1
1/4
3/4
Scale
]V2 Km.
_i
Mi.
32' 08'—|
32'06'—|
96'05'
I
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TRINIDAD LAKE
STORE! NO. 4836
I. INTRODUCTION
Trinidad Lake was included in the National Eutrophication Survey as
a water body of interest to the Texas Water Quality Board. Tributaries
and nutrient sources were not sampled, and this report relates only to the
lake sampling data.
Trinidad Lake, built in 1925, is owned by the Texas Power and Light
Company. Located immediately south of Trinidad, Texas, it is used as a
source of cooling water for power generation. The lake level is main-
tained by diversion of water from the Trinity River (Wyatt, 1975).
II. CONCLUSIONS
A. Trophic Condition:
Survey data indicate that Trinidad Lake is eutrophic; i.e.,
well supplied with nutrients and quite productive. Whether
nutrient enrichment is beneficial or deleterious depends on the
actual or potential effect on the uses of the lake. In this
regard, no nuisance conditions are known to personnel of the
Texas Water Quality Board and there is little or no impairment of
the designated beneficial uses of this water body.
Trinidad Lake ranked thirty-fifth in overall trophic quality
when the 39 Texas reservoirs sampled in 1974 were compared using
a combination of six parameters*. All of the other water bodies
had less median total and dissolved phosphorus, 14 had less and
two had the same median inorganic nitrogen, 36 had less mean
chlorophyll a^, and 34 had greater mean Secchi disc transparency.
* See Appendix A.
-------
Survey limnologists noted that the lake was extremely turbid
in March and reported emergent macrophytes in the shoreline shal-
lows in November.
B. Rate-Limiting Nutrient:
The algal assay results indicate that primary productivity
in Trinidad Lake was nitrogen-limited at the times the samples
were collected (03/11/74 and 11/01/74). The lake data indicate
nitrogen limitation at all sampling times.
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III. LAKE CHARACTERISTICS1"
A. Lake Morphometry :
1. Surface area: 2.99 kilometers2.
2. Mean depth: 3.1 meters.
3. Maximum depth: >2.4 meters.
4. Volume: 9.269 x 106 m3.
B. Precipitation*:
1. Year of sampling:. 120.8 centimeters.
2. Mean annual: 117.4 centimeters.
t Table of metric equivalents--Appendix B.
tt Latchford, 1975.
* See Working Paper No. 175, "...Survey Methods, 1973-1976",
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IV. LAKE WATER QUALITY SUMMARY
Trinidad Lake was sampled four times during 1974 by means of a
pontoon-equipped Huey helicopter. Each time, samples for physical
and chemical parameters were collected from two or more depths at
one station on the lake (see map, page vi). During each visit, a
single depth-integrated (near bottom to surface) sample was collected
for phytoplankton identification and enumeration; and a similar sample
was taken for chlorophyll a^ analysis. During the March and November
visits, single 18.9-liter depth-integrated samples were collected for
algal assays. The maximum depth sampled was 2.4 meters.
The sampling results are presented in full in Appendix C and are
summarized in the following table (nutrient samples collected in August
were not preserved properly and were not analyzed).
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PARAMETER
TEMP (C)
DISS OXY (MG/L)
CNOCTVY (MCROMO)
PH (STAND UNITS)
TOT ALK (MG/L)
TOT P (MG/L)
ORTHO P (MG/L)
N02«N03 (MG/L)
AMMONIA (MG/L)
KJEL N (MG/L)
INORG N (MG/L)
TOTAL N (MG/L)
CHLRPYL A (UG/L)
SECCHI (METEPS)
A. SUMMARY OF PHYSICAL AND
1ST SAMPLING ( 3/11/74)
1 SITES
RANGE MEAN MEDIAN
22.7 - 23.6 23.1 23.1
7.0 - 7.0 7.0 7.0
965. - 965. 965. 965.
8.8 - 8.9 8.8 8.8
199. - 200. 200. 200.
0.282 - 0.295 0.288 0.288
0.087 - 0.095 0.091 0.091
0.070 - 0.090 0.080 0.080
0.060 - 0.070 0.065 0.065
1.700 - 2.000 1.850 1.850
0.130 - 0.160 0.145 0.145
1.790 - 2.070 1.930 1.930
2.3 - 2.3 2.3 2.3
0.3 - 0.3 0.3 0.3
CHEMICAL CHARACTERISTICS FOR TRINIDAD
STORE.T CODE 4836
2ND SAMPLING ( 5/17/74)
1 SITES
RANGE
26.8 - 26.9
5.0 - 5.0
1037. - 1038.
8.4 - 9.0
203. - 203.
0.382 - 0.467
0.225 - 0.304
0.050 - 0.090
0.040 - 0.070
1.900 - 2.100
0.090 - 0.160
1.950 - 2.190
34.9 - 34.9
0.4 - 0.4
MEAN
26.9
5.0
1038.
8.7
203.
0.424
0.264
0.070
0.055
2.000
0.125
2.070
34.9
0.4
MEDIAN
26.9
5.0
1038.
8.7
203.
0.424
0.264
0.070
0.055
2.000
0.125
2.070
34.9
°0.4
3RD SAMPLING ( 8/12/74)
1 SITES
RANGE MEAN MEDIAN
30.4 - 32.0 31.3 31.5
7.<» - 10.8 9.5 10.2
1227. - 1260. 1246. 1252.
8.9 - 9.1 9.0 9.1
oocoeo -oooooooooooooooooo »ooo
27.4 - 27.4 27.4 27.4
0.8 - 0.8 0.8 O.d
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A. SUMMARY OF PHYSICAL AND CHEMICAL CHARACTERISTICS FOR TRINIDAD
STORET CODE 4836
4TH SAMPLING
l/7<»>
PARAMETER
TEMP (C)
DISS OXY (MG/L)
CNDCTVY (MCROMO)
PH (STAND UNITS)
TOT ALK (MG/L)
TOT P (MG/L)
ORTHO P (MG/L)
N02«N03 (MG/D
AMMONIA (MG/D
KJEL N (MG/L)
INORG N (MG/D
TOTAL N (MG/D
CHLRPYL A •
i7
1
0
0
0
'0
10
6
6
26.6
8.7
1032.
8.9
219.
0.426
0.288
0.025
0.055
1.700
0.080
1.725
32.6
0.6
MEDIAN
26.6
8.7
1032.
8.9
219.
0.426
0.288
0.025
0.055
1.700
0.080
1.725
32.6
0.6
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B. Biological characteristics:
1. Phytoplankton -
Sampli ng
Date
03/11/74
05/17/74
08/12/74
11/01/74
Dominant Algal Units
Genera per ml
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
Scenedesmus sj).
Cosmarium sp.
Centric diatoms
Golenkinia sp.
Nitzschia sj).
Other genera
Total
Dactyl ococcopsis sp.
Golenkinia sp.
Scenedesmus sp.
Cyclotella sp.
Merismopedia sp.
Other genera
Total
Merismopedia sp.
Lyngbya sp.
Nitzschia sp.
Scenedesmus sp.
Cyclotella sp.
Other genera
Total
Ankistrodesmus sp.
Scenedesmus sp.
Nitzschia sp.
Merismopedia sp.
Kirchneriella sjj.
Other genera
13,306
11,416
10,926
7,214
3,082
11,415
57,359
3,752
2,047
1,933
1,402
1,213
5,229
15,576
7,025
6,818
4,821
3,720
3,444
14,395
40,223
6,583
5,596
3,950
3,456
3,127
12,014
Total
34,726
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8
2. Chlorophyll a -
C.
Sampl i ng
Date
03/11/74
05/17/74
08/12/74
11/01/74
Station
Number
1
1
1
1
Chlorophyll a
(yg/1 )
2.3
34.9
27.4
32.6
Limiting Nutrient Study:
1. Autoclaved, fil
a. March sample
Spike (mg/1 )
Control
0.050 P
0.050 P + 1.0 N
1.0 N
tered, and nutrient spiked -
-
Ortho P
Cone, (mg/1)
0.015
0.065
0.065
0.015
Inorganic N
Cone, (mg/1)
0.059
0.059
1.059
1.059
Maximum yield
(mg/1 -dry wt.)
6.0
6.9
21.9
19.1
b. November sample -
Spike (mg/1 )
Control
0.050 P
0.050 P + 1.0 N
1.0 N
2. Discussion -
The control
Ortho P
Cone, (mg/1)
0.270
0.320
0.320
0.270
yields of the
Inorganic N
Cone, (mg/1)
0.113
0.113
1.113
1.113
0
Maximum yield
(mg/1 -dry wt.)
4.4
4.2
22.7
22.1
assay alga, Selenastrum capri-
cornutum, indicate that the potential primary productivity
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of Trinidad Lake was moderately high at the times the assay
samples were collected (03/11/74 and 11/01/74). Also, the
increase in yield when nitrogen alone was added and the lack
of significant increase when only orthophosphorus was added
indicate the lake was nitrogen limited at those times.
The lake data also indicate nitrogen limitation; i.e.,
the mean inorganic nitrogen/orthophosphorus ratios were 2/1
or less at all sampling times, and nitrogen limitation would
be expected.
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10
V. LITERATURE REVIEWED
Latchford, John B., Jr., 1974. Personal communication (lake mor-
phometry). TX Water Qual. Bd., Austin.
Wyatt, Linda B., 1975. Personal communication (general lake infor-
mation). TX Water Qual. Bd., Austin.
-------
11
VI. APPENDICES
APPENDIX A
LAKE RANKINGS
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LAKE UATA TO Bf
LAKE
CODE LAKE NAME
4601 AMISTAD LAKE
4802 BASTROP LAKE
4803 BELTON RESERVOIR
4804 BRAUNIG LAKE
4805 BROWNWOOD LAKE
4806 LAKE BUCHANAN
4807 CADDO LAKE
4808 CALAVERAS LAKE
4809 CANYON RESERVOIR
4810 LAKE COLORADO CITY
4811 CORPUS CRISTI LAKE
4812 DIVERSION LAKE
4813 EAGLE MOUNTAIN LAKE
4814 FT PHANTOM MILL LAKE
4815 GARZA LITTLE ELM RESERVO
4816 KEMP LAKE
4817 HOUSTON LAKE
4818 LAKE OF THE PINES
4819 LAVON RESERVOIR
4820 LIVINGSTON LAKE
4821 LYNDON B JOHNSON LAKE
4822 MEDINA LAKE
4823 LAKE MEREDITH
4824 PALESTINE LAKE
4825 POSSUM KINGDOM RESERVOIR
4826 SAN ANGELO RESERVOIR
4827 SAM RAY8URN RESERVOIR
4828 E V SPENCE RESERVOIR
MEDIAN
TOTAL P
0.013
0.02?
0.016
0.134
0.027
0.036
O.OS5
0.038
0.010
0.042
0.113
0.025
0.024
0.060
0.045
0.023
0.097
0.031
0.063
0.196
0.042
0.010
0.021
0.031
0.023
0.098
0.029
0.036
MEDIAN
INORG N
0.500
0.090.
0.185
0.150
0.100
0.250
0.070
0.060
0.450
0.090
0.130
0.080
0.070
0.105
0.380
0.110
0.260
0.090
0.180
0.555
0.420
0.600
0.070
0.180
0.070
0.140
0.150
0.080
500-
MEAN SEC
371.474
419.917
378.312
461.625
470.375
437.625
463.333
461.667
384.812
473.625
475.187
470.111
469.625
474.909
475.782
455.000
486.187
440.000
485.333
465.469
456.500
403.562
439.312
442.625
419,045
481.000
439.458
462.583
MEAN
CHLOKA
2.042
li.392
8.025
22.762
4.887
8.606
14.808
22.500
2.500
12.675
19.756
15.867
5.662
6.317
14.156
10.217
16.650
12.919
5.400
16.112
8.100
12.944
3.037
10.619
9.495
24.675'
6.267
11.775
15-
MIN DO
14.900
15.000
15.000
14.800
14.400
15.000
11.400
13.000
14.800
10.200
14.000
9.000
11.000
9.800
14.600
10.400
12.400
15.000
8.800
15.000
14.900
15.000
14.VOO
14.800
15.-000
1 0 . 200
15.000
15.000
MEDIAN
DISS OSTHO P
0.009
0.007
0.007
0.062
0.007
0.012
0.013
0.007
0.006
0.012
0.050
0.009
. 0.008
0.022
0.018
0.007
0.036
0.011
0.018
0.128
0.013
0.004
0.009
0.010
0.009
0.011
0.009
0.008
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LAKE DATA TO BE USED IN RANKINGS
LAKE
CODE LAKE NAME
4829 SOMERVILLE LAKE
4830 STAMFORD LAKE
4631 STILLMOUSE HOLLO* RESEKV
4832 TAWAKONI LAKE
4833 TEXARKANA LAKE
4834 TEXOMA LAKE
4835 TRAVIS LAKE
4836 TRINIDAD
4837 TWIN BuTTES RESERVOIR
4838 WHITE RIVER RESERVOIR
4839 WHITNEY LAKE
MEDIAN
TOTAL P
0.053
0.073
o.oia
0.046
0.106
0.042
0.018
0.389
0.029
0.020
0.028
MEDIAN
1NOWG N
0.115
O.C60
0.160
0.100
0.120
0.160
0.250
0.110
0.250
0.110
0.120
500-
MEAN SEC
473.833
482.714
406.250
466.417
478.500
451.321
389.913
479.500
454.917
434.500
430.500
MEAN
CHLOfiA
24.491
18.457
3.917
18.246
19.119
12.493
5.595
24.300
8.708
4.333
6.912
1S-
MIN DO
13.000
10.600
15.000
13.200
12.400
15.000
15.000
10.000
14.800
15.000
15.000
MEDIAN
DISS OrtTrtO P
0.013
0.012
0.010
0.013
0.030
0.018
0.007
0.240
0.009
0.009
0.008
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LAKE
CODE LAKE NAME
4801 AMISTAD LAKE
4802 BASTROP LAKE
4803 8ELTON RESERVOIR
4804 8RAUNIG LAKE
4805 BROrtNWOOD LAKE
4806 LAKE BUCHANAN
4807 CAODO LAKE
4808 CALAVERAS LAKE
4809 CANYON RESERVOIR
4810 LAKE COLORADO CITY
4811 CORPUS CRISTI LAKE
4812 DIVERSION LAKE
4813 EAGLE MOUNTAIN LAKE
4814 FT PHANTOM HILL LAKE
4815 GARZA LITTLE ELM RESERVO
4816 KEMP LAKE
4817 HOUSTON LAKE
4818 LAKE OF THE PINES
4819 LAVON RESERVOIR
4820 LIVINGSTON LAKE
4821 LYNDON B JOHNSON LAKE
4822 MEDINA LAKE
4823 LAKE MEREDITH
4824 PALESTINE LAKE
4825 POSSUM KINGDOM RESERVOIR
4826 SAN ANOELO RESERVOIR
4827 SAM RAYBURN RESERVOIR
4828 E V SPENCE RESERVOIR
MEDIAN
TOTAL P
95
79
92
5
66
47
26
45
99
39
8
68
71
24
34
76
16
54
21
3
39
99
82
5*
74
13
59
50
( 36)
( 30)
( 35)
I 2)
< 25)
( 18)
( 10)
( 17)
( 37)
( 14)
( 3)
( 26)
( 27)
( 9)
( 13)
( 29)
( 6)
( 20)
( 8)
( D
( 14)
< 37)
( 3D
( 20)
( 28)
( 5)
( 22)
( 19)
MEDIAN
INORG N
5 (
76 1
26 1
42 (
70 <
21 <
91 1
100 1
8 <
76 (
47 <
83 <
91 1
66 <
13 <
61 1
16 <
76 1
29 (
3 I
11 i
0 i
91 i
32
91 .
45 i
39 *
83 '
: 2)
1 28)
10)
: 16)
: 26>
; 7)
: 33)
; 38>
: 3)
( 28)
; ia>
: 3D
[ 33)
; 25)
1 5)
1 22)
I 6)
! 28)
I ID
! D
1 4)
1 0)
( 33)
1 12)
( 33)
( 17)
t 15)
( 3D
500-
MEAN SEC
100
82
97
50
29
74
42
47
95
26
18
32
34
21
16
55
0
66
3
39
53
89
71
63
84
8
68
45
( 38)
( 3D
( 37)
( 19)
( ID
( 28)
( 16)
( 18)
( 36)
( 10)
( 7)
( 12)
( 13)
( 8)
( 6)
( 21)
( 0)
( 25)
( 1)
( 15)
( 20)
( 34)
( 27)
( 24)
( 32)
( 3)
( 26)
( 17)
MEAN
CHLOHA
100
47
68
8
87
63
32
11
97
42
13
29
79
74
34
55
24
39
84
26
66
37
95
53
58
0
76
50
( 38)
( 18)
I 26)
( 3)
( 33)
( 24)
( 12)
( 4)
(37)
( 16)
( 5)
( ID
( 30)
( 28)
( 13)
I 2D
( 9)
( 15)
( 32)
( 10)
( 25)
( 14)
( 36)
(20)
( 22)
( 0)
( 29)
( 19)
15-
MIN UO
39 I
17 I
17 1
49 1
58 1
17 1
76 1
67 1
49 1
88 1
61 1
97 (
79 1
95 1
55 <
84 I
72 i
17 i
100 i
17 i
39
17
39
49
17
88
17
17
1 14)
I 0)
1 0)
I 17)
1 22)
[ 0)
( 29)
I 25)
1 17)
I 33)
[ 23)
I 37)
1 30)
[ 36)
I 21)
1 38)
1 27)
1 0>
1 38)
I 0)
I 14)
( 0)
( 14)
( 17)
( 0)
( 33)
( 0)
( 0)
MEDIAN
OISS OHTHO P
63
92
84
5
84
39
30
92
97
39
8
63
76
16
21
92
11
46
21
3
30
100
63
51
63
46
63
76
( 21)
( 34)
( 3D
( 2)
( 3D
( 14)
( 10)
( 34)
( 37)
( 14)
( 3)
( 21)
( 28)
( 6)
( 7)
( 34)
( 4)
( 17)
( 7)
( 1)
( 10)
( 38)
( 21)
( 19)
( 21)
( 17)
( 21)
( 28)
INDEX
NO
40<>
393
3B4
159
394
261
297
362
445
310
155
372
430
296
173
423
139
298
258
91
238
342
441
302
387
200
322
321
-------
PERCENT or LAKES KITH HIGHER VALUES (NUMBER OF LAKES *ITH HIGHER VALUES)
LAKE
CODE LAKE NAME
4829 SOMERVILLE LAKE
4830 STAMFORD LAKE
4831 STILLHOUSE HOLLOW
4832 TAWAKONI LAKE
4833 TEXARKANA LAKE
4834 TEXOMA LAKE
4835 TRAVIS LAKE
4836 TRINIDAD
4837 TWIN auTTES RESERVOIR
4838 WHITE RIVER RESERVOIR
4839 WHITNEY LAKE
MEDIAN
TOTAL P
29
18
88
32
11
39
88
0
59
84
63
( ID
( 7)
< 33)
( 12)
( 4)
( 14)
< 33)
< 0)
( 22)
< 32)
( 24)
MEDIAN
INORG N
55
*7
37
70
51
34
21
61'
21
61
51
( 21)
( 37)
( 14)
( 26)
( 19)
( 13)
( 7)
( 22)
< 7)
( 22)
( 19)
500-
MEAN SEC
24
5
87
37
13
61
92
11
58
76
79
( 9)
( 2)
( 33)
( 14)
( 5)
( 23)
( 35)
( 4)
( 22)
( 29)
( 30)
MEAN
CHLORA
3
18
92
21
16
45
82
5
61
89
71
( 1)
( 7)
< 35)
( 8)
( 6)
( 17)
( 3D
< 2)
< 23)
( 34)
( 27)
15-
MIN DO
67
82
17
63
72
17
17
92
49
17
17
( 25)
< 3D
( 0>
( 24)
( 27)
( 0)
( 0)
( 35)
( 17)
( 0)
( 0)
MEDIAN
DISS URTHO V
30
39
51
30
13
21
84
0
63
63
76
( 10)
( 14)
( 19)
( 10)
( 5)
I 7)
( 3D
( 0)
( 21)
( 21)
< 28)
INDEX
NO
208
259
372
2S3
176
217
384
169
311
390
357
-------
RANK LAKE CODE LAKE NAME
i 4809 CAMros RESERVOIR
2 4823 LAKE MEREDITH
3 4813 EAGLE MOUNTAIN LAKE
4 4816 KEMP LAKE
5 4801 AMISTAD LAKE
6 4805 BROrfNWOOD LAKE
7 4802 BASTRUP LAKE
8 4838 WHITE RIVER RESERVOIR
9 4825 POSSUM KINGDOM RESERVOIR
10 4835 TRAVIS LAKE
11 4803 BELTON RESERVOIR
12 4831 STILLHOUSE HOLLOW RESERV
13 4812 DIVERSION LAKE
14 4808 CALAVERAS LAKE
15 4839 WHITNEY LAKE
16 4822 MEDINA LAKE
17 4827 SAM RAYBURN RESERVOIR
18 4828 E V SPENCE RESERVOIR
19 4837 TWIN 8UTTES RESERVOIR
20 4810 LAKE COLORADO CITY
21 4824 PALESTINE LAKE
22 4818 LAKE OF THE PINES
23 4807 CADDO LAKE
24 4814 FT PHANTOM HILL LAKE
25 4806 LAKE BUCHANAN
26 4830 STAMFORD LAKE
27 4819 LAVON RESERVOIR
28 4832 TAWAKONI LAKE
INDEX NO
445
441
430
423
402
394
. 393
390
387
384
384
372
372
362
357
342
322
321
311
310
302
298
297
296
261
259
258
253
-------
LAKES RANKED BY INDEX NOS.
RANK LAKE CODE LAKE NAME INDEX NO
29 4821 LYNDON B JOHNSON LAKE 238
30 4834 TEXOMA LAKE 217
31 4829 SOMEHVILLE LAKE 208
32 4826 SAN AN6ELO RESERVOIR 200
33 4833 TEXARKANA LAKE 176
34 4815 GARZA LITTLE ELM RESERVO 173
35 4836 TRINIDAD 169
36 4804 8RAUNIG LAKE 159
37 4811 CORPUS CRISTI LAKE 155
38 4817 HOUSTON LAKE 139
39 %820 LIVINGSTON LAKE 91
-------
APPENDIX B
CONVERSION FACTORS
-------
CONVERSION FACTORS
Hectares x 2.471 = acres
Kilometers x 0.6214 = miles
Meters x 3.281 = feet
-4
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
t
Kilograms x 2.205 = pounds
Kilograms/square kilometer x 5.711 = Ibs/square mile
-------
APPENDIX C
PHYSICAL and CHEMICAL DATA
-------
STORET RETRIEVAL DATE 76/02/11
483601
32 06 55.0 096 05 45.0
TRINIDAD
48213 TEXAS
DATE
FROM
TO
74/03/11
74/05/17
74/08/12
74/11/01
DATE
FROM
TO
74/03/11
74/05/17
74/08/12
74/11/01
TIME DEPTH
OF
DAY FEET
14 15 0000
14 15 0008
10 05 0000
10 05 0007
15 05 0000
15 05 0003
15 05 0007
16 15 0000
16 15 0005
TIME DEPTH
OF
DAY FEET
14 15 0000
14 15 0008
10 05 0000
10 05 0007
15 05 0000
15 05 0005
16 15 0000
16 15 0005
00010
WATER
TEMP
CENT
23.6
22.7
26.9
26.8
32.0
31.5
30.4
26.6
26.5
00665
PHOS-TOT
MG/L P
0.295
0.282
0.467
0.382
0.457
0.396
00300
DO
MG/L
7.0
5.0
10.8
10.2
7.4
9.0
8.4
32217
CHLRPHYL
A
UG/L
2.3
34.9
27.4
32.6
00077
TRANSP
SECCHI
INCHES
12
17
30
23
00031
INCDT LT
REMNING
PERCENT
1.0
00094
CNDUCTVY
FIELD
MICROMHO
965
965
1038
1037
1260
1252
1227
1033
1031
11EPALES
3
00400
PH
SU
8.90
8.80
9.00
8.40
8.95
9.07
9.06
8.91
8.90
00410
T ALK
CAC03
MG/L
200
199
203
203
236
201
211
0012
00610
NH3-N
TOTAL
MG/L
0.060
0.070
0.070
0.040
0.060
0.050
1202
FEET DEPTH
00625
TOT KJEL
N
MG/L
2.000
1.700
2.100
1.900
1.800
1.600
00630
N02&N03
N-TOTAL
MG/L
0.070
0.090
0.090
0.050
0.030
0.020
00671
PHOS-DIS
ORTHO
MG/L P
0.095
0.087
0.304
0.225
0.321
0.255
------- |