U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
OKAUCHEE LAKE
WAUKESHA COUNTY
WISCONSIN
EPA REGION V
WORKING PAPER No, 64
PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY
An Associate Laboratory of the
NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON
and
NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA
& GPO—697.032
-------
REPORT
ON
OKAUCHEE LAKE
WAUKESHA COIMY
WISCONSIN
EPA REGION V
WORKING PAPER No, 64
WITH THE COOPERATION OF THE
WISCONSIN DEPARTMENT OF NATURAL RESOURCES
AND THE
WISCONSIN NATIONAL GUARD
JUNE, 1975
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1
CONTENTS
Page
Foreword ii
List of Wisconsin Study Lakes iv, v
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 9
VI. Appendices 10
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11
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 [ 3O3(e)], water
quality criteria/standards review [ 3O3(c)], clean lakes [ 3l4(a,b)],
and water quality monitoring [ lO6 and §305(b)] activities mandated
by the Federal Water Pollution Control Act Amendments of 1972.
* The lake discussed in this report was’ included in the National
Eutrophication Survey as a water body of interest to the Wisconsin
Department of Natural Resources. Nutrient sources were not sampled,
and this report relates only to the data obtained from lake sampling.
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111
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.
ACKNOWLEDGMENT
The staff of the National Eutrophication Survey (Office of
Research & Development, U. S. Environmental Protection Agency)
expresses sincere appreciation to the Wisconsin Department of
Natural Resources for professional involvement and to the Wisconsin
National Guard for conduct of the tributary sampling phase of the
Survey.
Francis H. Schraufnagel, Acting Assistant Director, and Joseph
R. Ball of the Bureau of Water Quality, and Donald R. Winter, Lake
Rehabilitation Program, provided invaluable lake documentation and
counsel during the Survey. Central Office and District Office per-
sonnel of the Department of Natural Resources reviewed the prelim-
inary reports and provided critiques most useful in the preparation
of this Working Paper series.
Major General James J. Lison, Jr., the Adjutant General of
Wisconsin, and Project Officer CW-4 Donald D. Erickson, who directed
the volunteer efforts of the Wisconsin National Guardsmen, are also
gratefully acknowledged for their assistance to the Survey.
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iv
NATIONAL EUTROPHICATION SURVEY
STUDY LAKES
STATE OF WISCONSIN
LAKE NAME COUNTY
Altoona Eau Claire
Beaver Dam Barron
Beaver Dam Dodge
Big Eau Pleine Marathon
Browns Racine
Butte des Morts Winnebago
Butternut Price, Ashland
Castle Rock Flowage Juneau
Como Walworth
Crystal Vilas
Delavan Walworth
Eau Claire Eau Claire
Geneva Walworth
Grand Green Lake
Green Green Lake
Kegonsa Dane
Koshkonong Jefferson, Rock, Dane
Lac La Belle Waukesha
Middle Walworth
Nagawicka Waukesha
Oconomowoc Waukesha
Okauchee Waukesha
Peteriwell Flowage Juneau
Pewaukee Waukesha
Pigeon Waupaca
Pine Waukesha
Poygan Winnebago, Waushara
Rock Jefferson
Rome Pond Jefferson, Waukesha
Round Waupaca
Shawano Shawano
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V
LAKE NAME COUNTY
Sinnissippi Dodge
Swan Columbia
Tainter Dunn
Tichigan Racine
Townline Oneida
Trout Vilas
Wapogassett Polk
Wausau Marathon
Willow Oneida
Winnebago Winnebago, Fond Du Lac,
Cal umet
Wisconsin Columbia
Wissota Chippewa
Yellow Burnett
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vi
,_— 7 43°1O
(II
Map Location
OKAUCHEE LAKE
Direct Drainage Area
Jounda ry
Indirect Drainage Basin
Lake Sampling Site
In butarv Sampi i ng
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OKAUCHEE LAKE
STORET NO. 5558
I. INTRODUCTION
Okauchee Lake was included in the National Eutrophication Survey as
a water body of interest to the Wisconsin Department of Natural Resources.
The inlet and outlet of the lake were sampled (Appendix C), but no waste-
water treatment plants impact the lake. Therefore, this report relates
only to the lake sampling data.
II. CONCLUSIONS
A. Trophic Condition:
Survey data and a report by others (Poff and Threinen, 1963)
indicate Okauchee Lake is in an early eutrophic condition. Of
the 46 Wisconsin lakes sampled, six had less mean total phosphorus,
four had less and one had the same mean dissolved phosphorus, 21
had less mean inorganic nitrogen, 13 had greater mean Secchi disc
transparency, and 20 lakes had less mean chlorophyll a. Depression
of dissolved oxygen with depth (37 feet and deeper) occurred at
station 2 in August and at 74 feet in November.
Submerged aquatic vegetation is a major use-problem (Poff and
Threinen, 1963), and the lake has received chemical treatment for
the control of both weeds and algae for a number of years (Lueschow,
1972).
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2
B. Rate-Limiting Nutrient:
The algal assay results indicate Okauchee Lake was phosphorus
limited at the time the sample was taken (11/11/72). The lake
data indicate phosphorus limitation in August as well but nitrogen
limitation in June.
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3
III. LAKE AND DRAINAGE BASIN CHARACTERISTICS
A. Lake Morphometryt:
1. Surface area: 1,104 acres.
2. Mean depth: 29.6 feet.
3. Maximum depth: 90 feet.
4. Volume: 32,688 acre-feet.
5. Mean hydraulic retention time: 300 days.
B. Tributary and Outlet:
(See Appendix A for flow data)
1. Tributaries -
Drainage area Mean flow
Name ( mi )* ( cfs)*
Oconomowoc River 74.3 48.5
Minor tributaries &
immediate drainage - 7.8 6.5
Totals 82.1 55.0
2. Outlet -
Oconomowoc River 83.8** 55Q**
C. Precipitation***:
1. Year of sampling: 38.7 inches.
2. Mean annual : 30.7 inches.
-I- WI Dept. Cons. lake survey map (1955).
* Drainage areas are accurate within ±0.5%; mean daily flows are accurate
within ±40%; mean monthly flows are accurate within ±35%; and nonnalized
monthly flows are accurate within ±35%.
** Includes area of lake; outflow adjusted to equal sum of inflows.
*** See Working Paper No. 1 , “Survey Methods, 1972”.
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4
IV. LAKE WATER QUALITY SUMMARY
Okauchee Lake was sampled three times during the open-water season
of 1972 by means of a pontoon—equipped Huey helicopter. Each time,
samples for physical and chemical parameters were collected from two
stations on the lake and usually from a number of depths at each sta-
tion (see map, page vi). During each visit, a single depth-integrated
(15 feet or near bottom to surface) sample was composited from the
stations for phytoplankton identification and enumeration; and during
the last visit, a single five-gallon depth-integrated sample was corn-
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 samples were 31 feet at station 1 and 77 feet at
station 2.
The results obtained are presented in full in Appendix B, and the
data for the fall sampling period, when the lake essentially was well-
mixed, are summarized below. Note, however, the Secchi disc summary
is based on all values.
For differences in the various parameters at the other sampling
times, refer to Appendix B.
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5
A. Physical and chemical characteristics:
FALL VALUES
Parameter Minimum Mean Median Maximum
Temperature (Cent.) 6.6 7.2 7.1 7.4
Dissolved oxygen (mg/l) 2.1 8.3 8.9 9.2
Conductivity (pmhos) 485 488 490 495
pH (units) 7.5 7.8 7.8 7.8
Alaklinity (mg/i) 188 202 201 214
Total P (mg/i) 0.015 0.018 0.016 0.033
Dissolved P (mg/i) 0.008 0.010 0.009 0.016
NO 2 + NO (mg/i) 0.140 0.206 0.220 0.250
Ammonia mg/l) 0.100 0.117 0.100 0.270
ALL VALUES
Secchi disc (inches) 12 75 72 113
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6
B. Biological characteristics:
1. Phytoplankton —
Sampling Dominant Number
Date Genera per ml
06/21/72 1. Fragilaria 796
2. Dinobryon 413
3. Stephanodiscus 199
4. Microcystis 127
5. Anabaena 121
Other genera 399
Total 2,055
08/19/72 1. Chroococcus 355
2. Dinobryon 347
3. Merismopedia 239
4. Synura 232
5. Oocystis 224
6. Fragilaria 224
Other genera 861
Total 2,482
11/11/72 1. Fragilaria 298
2. Anabaena 293
3. Dinobryon 195
4. Asterionella 166
5. Microcystis 119
Other genera 347
Total 1,418
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7
01
02
01
02
4.0
4.1
7.7
6.7
Maximum yield
( mg/i-dry wt. )
3.5
6.2
7.7
8.4
9.2
29.6
3.8
2. Chlorophyll a -
(Because of instrumentation problems during the 1972 sampling,
the following values may be in error by plus or minus 20 percent.)
Sampling Station ChlorOphyll a
Date Number ( pg/i )
06/21/72 01 12.7
02 14.9
08/1 9/72
11/11/72
C. Limiting Nutrient Study:
1. Autoclaved, filtered, and nutrient spiked -
Ortho P Inorganic N
Spike (mg/l) Conc. (mg/i) Conc. (mg/i ) _____________
Control 0.014 0.319
0.006 p 0.020 0.319
0.012 P 0.026 0.319
0.024 P 0.038 0.319
0.060 P 0.074 0.319
0.060 P + 10.0 N 0.074 10.319
10.0 N 0.014 10.319
2. Discussion -
The control yield of the assay alga, Selenastrum capri-
cornutum , indicates that the potential primary productivity
of Okauchee Lake was relatively high at the time the sample
was taken (11/11/72). Also, the results indicate that phos-
phorus was the growth-limiting nutrient. Note that the
addition of orthophosphorus resulted in increases in growth
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8
of the test alga, but there was not significant growth
response to the addition of nitrogen alone.
If all lake data are used, including the high nitrogen
values below 22 feet at station 2, phosphorus limitation
would be indicated at all sampling times. However, if only
values from the photic zone (assumed to be from the surface
to 22 feet) are used, the lake data indicate nitrogen limi-
tation in June (N/P = 8/1) and phosphorus limitation in
August (N/P = 19/1) and November (N/P = 18/1).
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9
V. LITERATURE REVIEWED
Lueschow, Lloyd A., 1972. Biology and control of selected aquatic
nuisances in recreational waters. Tech. Bull. No. 57, WI Dept.
Nat. Resources, Madison.
McKersie, Jerome, George Hansel, Floyd Stautz, and Dick Narf; 1969.
Report on an investigation of the pollution in the upper Rock
River drainage basin made during 1967—1968. WI Dept. Nat.
Resources, Madison.
Poff, Ronald J., and C. W. Threinen, 1963. Surface water resources
of Waukesha County, WI Cons. Dept., Madison.
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v. APPENDICES
APPENDIX A
TRIBUTARY FLOW DATA
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TRIBUTARY FLOW INFORMATION FOR WISCONSIN 9/30/74
LAKE CODE 5558 OCKAUCHEE LAKE
TOTAL DRAINAGE AREA OF LAKE 83.80
SUB—DRAINAGE NORMALIZEO FLOWS
TRIBUTARY AREA JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MEAN
5558A1 74.30 27.00 32.00 85.00 110.00 64.00 74.00 34.00 24.00 31.00 31.00 44.00 26.00 48.46
5558A2 83.80 31.20 35.10 93.60 126.70 72.10 85.80 39.00 27.20 35.10 36.10 49.70 30.20 55.10
SSSRZZ 9.50 3.60 4.00 11.00 14.00 8.40 10.00 4.50 3.20 4.00 5.80 5.80 3.50 6.48
SUMMARY
TOTAL DRAINAGE AREA OF LAKE = 83.80 TOTAL FLOW IN = 659.80
SUM OF SUB—DRAINAGE AREAS = 83.80 TOTAL FLOW OUT = 661.80
MEAN MONTHLy FLOWS AND DAILY FLOWS
TRIRUTARY MONTM YEAR MEAN FLOW DAY FLOW DAY FLOW DAY FLOW
SS SRA I 9 72 110.00 23 180.00
10 72 130.00
II 72 99.00
12 72 38.00 9 32.00
I 73 77.00
2 73 56.00 II 56.00
3 73 130.00 18 180.00
4 73 340.00 14 230.00 29 210.00
S 73 P20.00 22 160.00 26 180.00
6 73 87.00 16 78.00
7 73 24.00 I 36.00
8 73 16.00 26 17.00
9 72 130.00 23 200.00
10 72 150.00
II 72 110.00
I? 72 43.00 9 35.00
1 73 89.00
2 73 67.00 ii 67.00
3 73 150.00 18 210.00
4 73 380.00 14 250.00 29 230.00
S 73 250.00 22 180.00 26 200.00
6 73 98.00 16 92.00
7 73 27.00 1 40.00
8 73 18.00 26 19.00
S S SRZZ 9 72 10.00 23 27.00
10 7 20.00
II 72 15.00
I? 72 5.80 9 4.80
1 73 6.00
2 73 1.20 II 3.20
1 71 11.00 16 14.00
4 73 76.00 14 52.00 /9 34.00
5 73 36.00 ?2 26.00 26 29.00
6 73 0.50 16 9.00
7 73 6.30 I 6.40
8 73 3.00 ?6 3.00
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APPENDIX B
PHYSICAL and CHEMICAL DATA
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STDPET RETRIEVAL DATE 74/09/JO
555801
43 07 54.0 088 04 48.0
OKAUCHEE LAKE
55 WISCONSIN
1 IIPAL.ES 2111202
3 0008 FEET DEPTH
DATE
FROM
TO
TIME DEPTH
OF
DAY FEET
7?/06/?1 13 50 0000
7?/OA/19 14 10 0000
14 10 0004
14 10 0009
7?/fl/11 10 30 0000
10 30 0004
10 30 0015
10 30 002?
10 30 0031
00010
00300
00077
00094
00400
00410
00630
00610
00665
00666
WATER
DO
TRANSP
CNOIJCTVY
PH
1
ALK
NO21 NO3
NH3—N
PHOS—TOT
PHOS-DIS
TEMP
SECCHT
FIELD
CACO3
N—TOTAL
TOTAL
CENT
MG/L
INCHES
MICROMHO
SU
MG/L
MG/L
MG/L
MG/L P
MG/L P
15.9
10.0
72
12
385
410
8.50
8.41
187
169
0.020
0.060
0.030
0.090
0.022
0.015
0.009
0.008
26.2
9.8
408
8.45
166
0.070
0.080
0.012
0.007
24.0
10.6
113
410
490
8.40
7.80
166
210
0.060
0.250
0.070
0.110
0.018
0.016
0.007
0.008
7.1
9.2
490
7.80
210
0.240
0.100
0.017
0.009
7.1
9.2
490
7.80
188
0.240
0.110
0.015
0.010
7.1
9.2
490
7.80
206
0.240
0.100
0.017
0.009
7.1
9.0
490
7.80
214
0.250
0.100
0.016
0.010
DATE
FROM
TO
7?/06/21
7?/0 8/19
7?/1 1/11
TIME DEPTH
OF
DAY FEET
13 50 0000
14 10 0000
10 30 0000
32217
C fIL P P H YL
A
UG IL
12.7J
4.OJ
7.7 1
J VALUE KNOWN TO BE IN ERROR
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STORET RETRIEVAL DATE 74/09/30
555802
43 07 12.0 088 05 42.0
OI AUCr1EE LAf E
55 WISCONSIN
I IEPALES
3
2111202
0045 FEET DEPTH
00010
00300
00077
00094
00400
00410
O0’ 30
00610
00665
00666
DATE
TIME
flF°TH
WATER
f)(•)
TRANSP
CNDUCTVY
PH
T
AL <
NO2 NO3
NH3—N
PHOS—TOT
Pr4OS—DIS
FROM
OF
TEMP
cEccHI
FIELD
CACOI
M—TOTAL
TOTAL
TO
DAY
FFET
CENT
‘lr,/L
INCHES
MICPOMHO
SU
MG/L
MG/L
MG/L
MG/I P
MG/I P
72/06/21
14 05
0000
16.5
9.6
72
385
8.60
187
0.030
0.030
0.015
0.006
14 05
0015
20.1
9.6
385
8.60
186
0.030
0.040
0.016
0.008
14 05
0040
6.4
7.2
405
7.80
186
0.300
0.040
0.021
0.008
7?/C8/19
14 40
0000
400
8.45
168
0.060
0.070
0.0 15
0.009
14 40
0004
76.5
8.9
: 98
8.40
174
0.060
0.060
0.011
0.007
14 40
0015
22.5
8.0
410
8.30
179
0.060
0.070
0.011
0.007
!4 40
0022
20.2
8.0
410
8.25
179
0.060
0.050
0.011
0.005
16 ‘0
0027
12.6
6.7
440
7.80
195
0.190
0.050
0.016
0.006
16 40
0037
7.7
3.4
445
7.50
206
0.400
0.040
0.011
0.006
14 40
0047
6.6
3.5
450
7.45
196
0.450
0.050
0.014
0.006
14 40
0057
5.9
4.0
448
7.45
196
0.460
0.040
0.012
0.006
14 40
0067
5.3
4.0
450
7.50
196
0.470
0.050
0.0 11
0.006
14 60
0077
5.1
3.2
450
8.25
198
0.500
0.050
0.0 14
0.007
72/11/11
10 50
0000
107
490
7.80
206
0.220
0.100
0.015
0.008
10 50
0004
7.4
Q•9
485
7.80
202
0.220
0.100
0.016
0.009
10 50
0015
7.4
8.7
480
7.80
200
0.210
0.100
0.0 16
0.009
tO 50
0022
7.4
8.8
480
7.80
199
0.220
0.100
0.017
0.009
tO 50
0035
7.3
8.9
485
7.80
199
0.220
0.110
0.017
0.009
10 50
0050
7.0
8.8
490
7.80
200
0.220
0.100
0.019
0.009
10 50
0074
6.6
2.1
495
7.50
194
0.140
0.270
0.033
0.016
DATE
TIME
DEPTH
32 I?
CHLPPHYL
FROM
OF
A
TO
DAY
FEET
UG/L
72/06/21
14 05
0000
14.9J
72/08/19
14 40
0000
4. IJ
77 /11/11
10 50
0000
6.7J
3 VALUE KNOWN TO BE IN ERROR
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APPENDIX C
TRIBUTARY DATA
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dEl ETPI’ VAL )AT f’./10/’)’
L ’-’ 1
43 0 30.0 0 24 30.0
t CiJ iQ’ 1OW3C -‘1 VE’
15 A)1LA’II)
J/U lK IJCHEE LA F
C l ‘-lw( 1K A1N , . EDG1 STONESANK
11 I PALES 2111204
4 0000 FLET 1jEi. T -4
00’ 30 O Ois?c 0 00 S7I
•3a1F TIME ) [ -‘T-l iO ‘k.NO TOT r(JcL l\j-43—I\ P ,OS—nIS PHOS—JOt
‘J-TOTaL N 1OTAL
T ) lAY FEEt NIG/L 1(/L -) i6/L
7?/0 /23 14 6’ 0.170 1.050 0.010 0.04
7?/11/03 11 30 0.440 0.U70 0.0?? f l.015 0.13 ?
7?/12/0 13 45 0. 70 1.3Pt) 0.0 f u.( 3 0.0
71f0l/Oe 14 00 0.775 1.320 0.0 - 0.0 f- 0.070
7 3/02/ I l 1 15 O. iR’) 0. 3 0 0.0 05 0.026 0. OSS
71/03/1k 09 45 0.RR O 0.750 0.027 0.035
71/04/1k 14 40 0.H00 0.940 0.017 0.0?1 0.055
71/06/?0 14 50 0.7 0 1.700 C.03f 0.011 U.0 5
73/C5/2 13 30 0.240 0. A0 U.0 3 1.007
71/05/ ? 13 30 0.1 ’) 1.000 0.01 0.015 0.040
71/0 /1 1 10 0.5 ’) 1.10’ 0.072 C.03i 0.070
7 /07/0I 10 00 0. ?9 1. C’ (J .fl44 0.011
73/’ /? ’ 1400 0.220 0.0?7 0.013
-( V -LU- .‘iO ’ Tfl t L c
T1 l.E l I 1)ICI TE
-------
5T3 ET PETPIEVAL DATE 7 ./10/O?
41 0’ 0.0 0 28 30.0
OCONOMOWOC J [ P
55 15 -iAPTLAN )
U/OKA’JC’rIEE LAI E
U 16 - PUc, vi OF OKAUCiIEE
11E ALES 2111204
4 0000 FcET DEPTH
00 ’30 00f? 0O 10 00671 00665
DAtE TIME DE-’T -l N0 N01 ior KJEL N’-i3— PrIOS—PIS PHOS—TOT
FPOM OF N—TOTAL N TOTAL Ui ?19O
TO DAY FEET MG/L G/L M(/L /L v MG/L P
72/09/23 15 00 0.297 1.100 (1.140 0.00 K 0.024
72/11/05 13 40 0. P0 0.O 0 0.001 0.016
7?/I?/04 1400 0.250 0.610 0.32? 0.002
73/01/06 15 45 0.29 ’) 0.730 (i.0? 6 0.003 0.0?O
7 3//lI 14 12 0.340 0.720 0.007 (1.005 0.025
71/O1/1 10 45 0.430 1.000 0.026 0.007 0.155
71/04/14 13 45 0.350 O. ’ )40 0.014 0.005K 0.035
71/04/2° 14 15 0.176 1.10 ) 0.016 0.006 0.026
71/05/ ! ? 14 30 0.? 0 0.970 0.026 0.010 0.030
71/05/2 14 50 0.160 1.760 s.05? 0.006 0.U35
71/06/16 11 25 0.O? 1.200 0.048 0.003 O.03u
71/07/01 13 10 0.007 1.000 0.060 0.004 0.031)
73/0 /76 0.013 0.780 0.046 0.008
K V LU NC’.IN 1) U
TH- N 1 ’’D1CCT1
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