U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2009–5089 

In cooperation with the Whitefish Lake Conservation Organization (WILCO) through the 

Town of Wascott, Wisconsin 

Water Quality and Hydrology of Whitefish (Bardon) Lake, 

Douglas County, Wisconsin, With Special Emphasis on 

Responses of an Oligotrophic Seepage Lake to Changes 

in Phosphorus Loading and Water Level 

Water Quality and Hydrology of Whitefish 

(Bardon) Lake, Douglas County, Wisconsin, 

With Special Emphasis on Responses of an 

Oligotrophic Seepage Lake to Changes in 

Phosphorus Loading and Water Level 

By Dale M. Robertson, William J. Rose, and Paul F. Juckem 

In cooperation with the Whitefish Lake Conservation Organization (WILCO) 

through the Town of Wascott, Wisconsin 

Scientific Investigations Report 2009–5089 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2009

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Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Robertson, D.M., Rose, W.J., and Juckem, P.F., 2009, Water quality and hydrology of Whitefish (Bardon) Lake, Douglas 

County, Wisconsin, with special emphasis on responses of an oligotrophic seepage lake to changes in phosphorus 

loading and water level: U.S. Geological Survey Scientific Investigations Report 2009–5089, 41 p. 

Cover photos showing changes in the water level in Whitefish Lake. (All photos by Dale M. Robertson.) 

Upper left–High water near the south shore of Whitefish Lake, August 2004.

Upper right–High water near the small peninsula in the South Basin of Whitefish Lake, August 2004; 

pictured are Fred Anderson, Sandra Anderson, and William Rose. 

Lower left–Low water near the south shore of Whitefish Lake, May 2007.

Lower right–Low water near the small peninsula in the South Basin of Whitefish Lake, May 2007.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................2

Whitefish Lake and Its Watershed.....................................................................................................2

Effects of Changes in Nutrient Loading, Water Level, and Climate on Water Quality ..............4

Purpose and Scope ..............................................................................................................................5

Study Methods and Sampling Sites............................................................................................................5

Lake-Stage and Water-Quality Monitoring.......................................................................................6

Lake Classification................................................................................................................................6

Lake-Sediment Analyses.....................................................................................................................6

Meteorology and Atmospheric Deposition Monitoring..................................................................7

Outlet Monitoring..................................................................................................................................7

Surface-Water Inflow ..........................................................................................................................7

Groundwater Monitoring.....................................................................................................................9

Simulation of Groundwater Flow near Whitefish Lake...................................................................9

Water Quality of Whitefish Lake................................................................................................................11

Inferred Lake Water Quality from Lake-Sediment Analyses ................................................................16

Hydrology and Water Budget ....................................................................................................................16

Change in Storage ..............................................................................................................................17

Precipitation.........................................................................................................................................17

Evaporation and Net Groundwater Inflow......................................................................................19

Surface-Water Inflow ........................................................................................................................20

Surface-Water Outflow......................................................................................................................21

Groundwater Inflow and Outflow.....................................................................................................21

Water-Budget Summary....................................................................................................................22

Sources of Phosphorus...............................................................................................................................23

Precipitation.........................................................................................................................................24

Surface-Water Inflow ........................................................................................................................28

Groundwater........................................................................................................................................28

Septic Systems....................................................................................................................................29

Surface-Water Outflow .....................................................................................................................29

Phosphorus-Budget Summary .........................................................................................................30

Simulated Changes in Water Quality in Response to Changes in Phosphorus 

Loading and Water Level ..............................................................................................................31

Modeling Approach ...........................................................................................................................31

Verification and Adjustments for Model Biases............................................................................34

Sensitivity of Model Predictions to Assumptions in Load Estimations .....................................34

Response in Water Quality to Basinwide Changes in Phosphorus Loading.............................34

Response in Water Quality to Specific Anthropogenic and Natural Scenarios ......................35

Historical Changes in Water Levels and Water Quality in Whitefish Lake ........................................35
iv

Relative Importance of Anthropogenic Changes in the Watershed and Changes 

in Water Level .................................................................................................................................36

Summary and Conclusions.........................................................................................................................38

References Cited..........................................................................................................................................39 

Figures

1–2. Photographs showing:

1. Whitefish (Bardon) Lake, Douglas County, Wis., with data-collection sites 

identified................................................................................................................................3

2. The meteorological station installed on the southwest shore of 

Whitefish Lake......................................................................................................................8

3. Map showing the hydrologic features simulated with the GFLOW 

groundwater-flow model near Whitefish Lake......................................................................10

4–22. Graphs showing:

4. Measured and simulated heads for the calibrated GLFLOW model for the 

area near Whitefish Lake .................................................................................................12

5. Near-surface total phosphorus concentrations, chlorophyll a concentrations, 

and Secchi depths in the South and North Basins of Whitefish Lake, 

1998 to 2008.........................................................................................................................13

6. Near-bottom total phosphorus concentrations in the South and North 

Basins of Whitefish Lake, 1998 to 2006 ..........................................................................15

7. Trophic-state-index values based on surface concentrations of total 

phosphorus and chlorophyll a, and Secchi depths, in the South Basin of 

Whitefish Lake, 1998 to 2008 ............................................................................................16

8. Estimated changes in summer total phosphorus concentrations based 

on changes in the diatom community in the sediment cores from Whitefish 

Lake, and inferred concentrations adjusted to that measured from 

2002 to 2004.........................................................................................................................17

9. Measured and computed daily water levels from the full water budget of 

Whitefish Lake, November 1, 2004, to October 31, 2006..............................................18

10. Precipitation at Whitefish Lake, November 2004 to October 2006, relative 

to long-term average precipitation at Gordon, Wis. ...................................................18

11. Measured and modeled (with the Dynamic Lake Model) distribution of 

water temperature, April 20, 2005, to December 31, 2006...........................................20

12. Daily evaporation from the surface of Whitefish Lake, November 2004 

through December 2006, based on output from the Dynamic Lake Model..............21

13. Simulated groundwater contributing area and flow directions near 

Whitefish Lake, from the GFLOW groundwater-flow model.......................................22

14. Water budgets for Whitefish Lake, for monitoring years 2005 and 2006..................23

15. Monthly total water inputs and outputs plus storage change for Whitefish 

Lake, based on results from the water-balance model...............................................24

16. Measured stage in Whitefish Lake, compared to the estimated stage from 

the water-budget model with no overland flow from nearshore areas for the 

2-day event occurring during October 4–5, 2005..........................................................24
v

17. Total phosphorus concentrations measured during wetfall events and daily 

dryfall deposition rates measured during periods with no precipitation in 

monitoring years 2005 and 2006, near Whitefish Lake ................................................25

18. Monthly atmospheric wetfall and dryfall of total phosphorus into Whitefish 

Lake, during monitoring years 2005 and 2006 ...............................................................28

19. Phosphorus budgets for Whitefish Lake, for monitoring years 2005 and 2006 .......30

20. Measured and simulated average summer near-surface concentrations of 

total phosphorus, chlorophyll a, and Secchi depths in Whitefish Lake, in 

response to various phosphorus-loading scenarios ...................................................33

21. Estimated and measured lake stage in Whitefish Lake and Bluegill Lake, 

Wis., 1900 to 2008...............................................................................................................36

22. Adjusted inferred total phosphorus concentrations in the South Basin of 

Whitefish Lake, compared to the estimated lake stage in Whitefish Lake, 

1900 to 2008.........................................................................................................................37 

Tables

1. Morphometric characteristics of the basins in Whitefish (Bardon) Lake, 

Douglas County, Wis. ...................................................................................................................2

2. Near-surface summer average water quality and trophic-state-index values 

for Whitefish Lake.......................................................................................................................14

3. Water budget for Whitefish Lake for monitoring years 2005 and 2006..............................19

4. Total phosphorus deposition rates for Whitefish Lake and rates for other types 

of land cover................................................................................................................................26

5. Phosphorus budget for Whitefish Lake for monitoring years 2005 and 2006, 

and for a series of dry and wet years......................................................................................29

6. Estimated water quality in Whitefish Lake in response to various phosphorusloading scenarios .......................................................................................................................32 
vi

Multiply By To obtain

Length

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 0.004047 square kilometer (km2

)

Volume

acre-foot (acre-ft) 1,233.5 cubic meter (m3

)

Mass and weight

pound, avoirdupois (lb) 0.4536 kilogram (kg)

Miscellaneous rates and yields

inch per day (in/d) 25.4 millimeter per day (mm/d)

inch per year (in/yr) 25.4 millimeter per year (mm/yr)

foot per day (ft/d) 0.3048 meter per day (m/d)

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

pound per year (lb/yr) 0.4536 kilogram per year (kg/yr) 

pound per square mile (lb/mi2

) 0.1751 kilograms per square kilometer 

(kg/km2

)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

 °F=(1.8×°C)+32 

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25°C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).

*Hydraulic conductivity: The standard unit for hydraulic conductivity is cubic foot per day per 

square foot of aquifer cross-sectional area (ft3

/d/ft2). In this report, the mathematically reduced 

form, foot per day (ft/d), is used for convenience. 

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29). 

Conversion Factors and Abbreviations
vii

Acknowledgments 

Technical Reviewers

Timothy Asplund, Statewide Limnologist, Wisconsin Department of Natural Resources, 

Madison, Wis.

Herbert S. Garn, Hydrologist (Scientist Emeritus), U.S. Geological Survey, Middleton, Wis.

Paul Garrison, Research Scientist, Wisconsin Department of Natural Resources, Madison, Wis.

Pamela Toshner, Lake and River Management Coordinator, Wisconsin Department of 

Natural Resources, Spooner, Wis.

Local Project Coordinators

Sandra Anderson, Whitefish Lake Resident, Past-president of Whitefish Lake Conservation 

Organization, Gordon, Wis.

Fred Anderson, Whitefish Lake Resident, Gordon, Wis.

Pamela Toshner, Lake and River Management Coordinator, Wisconsin Department of 

Natural Resources, Spooner, Wis.

Editorial and Graphics

Elizabeth A. Ciganovich, Technical Editor, U.S. Geological Survey, Madison, Wis.

Michelle M. Greenwood, Reports Specialist, U.S. Geological Survey, Middleton, Wis.

James L. Kennedy, Geographer, U.S. Geological Survey, Middleton, Wis.

Laura L. Nelson, Computer Assistant, U.S. Geological Survey, Middleton, Wis.

Data Collection

Tom Popowski, Hydrologic Technician (retired), U.S. Geological Survey, Rice Lake, Wis.

Josef G. Schuler, Hydrologic Technician, U.S. Geological Survey, Rice Lake, Wis.

Vicki and David Van Ells, Local observers for the weather station, Gordon, Wis.

David and Mary Lou Rossmeisl, Local observers for the weather station, Gordon, Wis.

Fred Anderson, Local observer for discharge from Whitefish Lake, Gordon, Wis. 

Approving Official

Kevin J. Breen, Acting Bureau Approving Official, U.S. Geological Survey, New Cumberland, 

Penn. 
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Water Quality and Hydrology of Whitefish (Bardon) Lake, 

Douglas County, Wisconsin, With Special Emphasis on 

Responses of an Oligotrophic Seepage Lake to Changes 

in Phosphorus Loading and Water Level 

By Dale M. Robertson, William J. Rose, and Paul F. Juckem 

Abstract

Whitefish Lake, which is officially named Bardon Lake, 

is an oligotrophic, soft-water seepage lake in northwestern 

Wisconsin, and classified by the Wisconsin Department of 

Natural Resources as an Outstanding Resource Water. Ongoing monitoring of the lake demonstrated that its water quality 

began to degrade (increased phosphorus and chlorophyll a

concentrations) around 2002 following a period of high water 

level. To provide a better understanding of what caused the 

degradation in water quality, and provide information to better 

understand the lake and protect it from future degradation, 

the U.S. Geological Survey did a detailed study from 2004 

to 2008. The goals of the study were to describe the past and 

present water quality of the lake, quantify water and phosphorus budgets for the lake, simulate the potential effects 

of changes in phosphorus inputs on the lake’s water quality, 

analyze changes in the water level in the lake since 1900, and 

relate the importance of changes in climate and changes in 

anthropogenic (human-induced) factors in the watershed to the 

water quality of the lake.

Since 1998, total phosphorus concentrations increased 

from near the 0.005-milligrams per liter (mg/L) detection limit 

to about 0.010 mg/L in 2006, and then decreased slightly in 

2007–08. During this time, chlorophyll a concentrations and 

Secchi depths remained relatively stable at about 1.5 micrograms per liter (μg/L) and 26 feet, respectively. Whitefish 

Lake is typically classified as oligotrophic.

Because the productivity in Whitefish Lake is limited by 

phosphorus, phosphorus budgets were constructed for the lake. 

Because it was believed that much of its phosphorus comes 

from the atmosphere, phosphorus deposition was measured in 

this study. Phosphorus input from the atmosphere was greater 

than computed based on previously reported wetfall phosphorus concentrations. The concentrations and deposition rates 

can be used to estimate atmospheric loading in future lake 

studies. The average annual load of phosphorus to the lake 

was 232 pounds: 56 percent from precipitation, 27 percent 

from groundwater, and 16 percent from septic systems. During 

a series of dry years (low water levels) and wet years (high 

water levels), the inputs of water and phosphorus ranged by 

only 10–13 percent. 

Results from the Canfield and Bachmann eutrophication 

model and Carlson trophic-state-index equations demonstrated 

that the lake directly responds to changes in external phosphorus loading, with percent change in chlorophyll a being 

similar to the percent change in loading and the change in total 

phosphorus and Secchi depth being slightly smaller. Therefore, changes in phosphorus loading should affect the water 

quality of the lake. Specific scenarios that simulated the effects 

of anthropogenic (human-induced) and climatic (water level) 

changes demonstrated that: surface-water inflow (runoff) 

based on current development has little effect on pelagic water 

quality, changes in the inputs from septic systems and development in the watershed could have a large effect on water 

quality, and decreases in water and phosphorus loading during 

periods of low water level had little effect on water quality. 

Sustained high water levels, resulting from several wet years 

with relatively high water and phosphorus input, however, 

could cause a small degradation in water quality. Although 

high water levels may be associated with a degradation in 

water quality, it appears that anthropogenic changes in the 

watershed may be more important in affecting the future water 

quality of the lake.

Fluctuations in water levels since 1998 are representative 

of what has occurred since 1900, with fluctuations of about 

3 feet occurring about every 15 years. Based on total phosphorus concentrations inferred from sediment core analysis, there 

has been little long-term change in water quality and there 

has been a slight deterioration in water quality following most 

periods of high water levels. Therefore, the recent degradation 

in water quality appears to be consistent with what may have 

occurred several times in the past associated with high water 

levels. 

Whitefish Lake is presently a relatively pristine lake 

and is classified as an Outstanding Resource Water primarily because of the small contributions of phosphorus from its 

watershed. Controls to minimize the phosphorus input to the 

lake are very important because what many would consider a 

small increase in phosphorus loading in most lakes could have 

a large effect on the phosphorus budget and water quality of 

Whitefish Lake.
2 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Introduction

Whitefish Lake, which is officially named Bardon Lake, 

is a soft-water seepage lake in northwestern Wisconsin. The 

Wisconsin Department of Natural Resources (WDNR) has 

classified the lake as an Outstanding Resource Water because 

of the lake’s excellent water quality, high recreational and aesthetic value, and high quality fishing. Outstanding Resource 

Waters are believed to be free from point-source and nonpointsource pollution (Wisconsin Department of Natural Resources, 

2008a). Based on data collected by the Citizen Lake Monitoring Network (Citizen Monitoring; Wisconsin Department of 

Natural Resources, 2008b), it appeared that the water quality 

of the lake was beginning to degrade: phosphorus and chlorophyll a (algae) concentrations measured in 2002–04 were 

higher than those measured in 1998–99. The higher phosphorus concentrations followed several years of relatively high 

water levels in the lake. Local residents were unsure whether 

the increased phosphorus concentrations were caused by 

natural, climatic effects associated with the high water levels 

or some anthropogenic factor(s) in the watershed. To better 

understand the cause of the apparent degradation in water 

quality, a detailed study was conducted from 2004 to 2008 by 

the U.S. Geological Survey (USGS). This study was done in 

cooperation with the Whitefish Lake Conservation Organization (WILCO; http://www.uwsp.edu/cnr/landcenter/whitefish_

lake/) through the Town of Wascott, Wis., and was partially 

funded through the Lake Protection Grant Program of the 

WDNR and the Cooperative Water Program of the USGS. The 

results of this study are described in this report. Specifically, 

the water quality and hydrology of the lake are described, 

sources of phosphorus are quantified, and the effects of past 

and future changes in phosphorus inputs on the water quality 

of the lake are determined, especially with respect to changes 

in the water level of the lake. This study was part of an interdisciplinary project conducted on Whitefish Lake to provide 

information for local managers to develop a comprehensive 

lake-management plan. Other aspects of this project examined 

the lake sediments (paleolimnology), plankton, macrophytes, 

fish, and sociological information to improve the understanding and protection of the lake.

Whitefish Lake and Its Watershed

Whitefish Lake (fig. 1) is a natural seepage lake in Douglas County, in northwestern Wisconsin, which is about 25 mi 

northwest of Hayward, Wis., and 3 mi southwest of Gordon, 

Wis. Seepage lakes are closed-basin lakes that do not have an 

inlet or an outlet, and only occasionally overflow (Wisconsin 

Department of Natural Resources, 1999; Shaw and others, 

2002). Whitefish Lake only rarely overflows into a small 

wetland (Deborah Lake) on the southeast side of lake. Because 

Whitefish Lake is primarily a landlocked waterbody, its principal sources of water are precipitation and groundwater, which 

may be supplemented by direct runoff from its small surrounding drainage area. 

The drainage area of Whitefish Lake is 520 acres (fig. 1). 

The landcover in the watershed is primarily a mixture of 

deciduous hardwood (68 percent) and pine (30 percent) forest 

(Homer and others, 2007). The soil around Whitefish Lake 

consists primarily of Menahga sand with 0–12 percent slope 

(U.S. Department of Agriculture, 2006b). The Menahga series 

consists of very deep, well to excessively drained soils that 

formed in sandy glacial-outwash sediments on valley plains, 

moraines, and drumlins. These soils are very permeable, with 

minimum infiltration rates of 5–10 in/hr (Young and Hindall, 

1973). Therefore, in the absence of anthropogenic compaction 

of the soils, very little surface runoff should reach the lake 

except during extremely large storms and, possibly, during 

spring runoff when the ground may be partially frozen.

The area and volume of Whitefish Lake were given on 

the 1967 Wisconsin Conservation Department lake survey 

map as 831.5 acres and 25,334 acre-ft, respectively. In this 

study, the morphometry of the lake was reevaluated based on 

an aerial image obtained in 2005 by the National Agricultural 

Imagery Program (U.S. Department of Agriculture, 2006a). 

In 2005, the lake was near full volume, similar to when the 

original map was constructed in 1967. The resulting surface 

area of the lake was determined to be 833 acres from the aerial 

image, which results in the drainage basin to lake area ratio of 

only 0.62. All bathymetric contours were then adjusted to the 

new surface area of the lake. The volume was then determined 

to be 24,184 acre-ft (table 1); slightly different values from 

the original estimates. All of the calculations in this study 

are based on the recently estimated morphometry. The lake 

consists of two basins (North and South Basins) connected by 

a narrows (fig. 1). The South Basin has a maximum depth of 

about 102 ft, whereas the maximum depth of the North Basin 

is about 60 ft (table 1). 

Table 1. Morphometric characteristics of the basins in Whitefish (Bardon) Lake, Douglas County, Wis. 

Basin Area 

(acres)

Length 

(miles)

Width 

(miles)

Maximum depth 

(feet)

Mean depth 

(feet)

Volume 

(acre-feet)

North 376 1.42 0.46 60 26.12 9,616

South 457 1.26 .87 102 31.88 14,568

Entire lake 833 2.55 .67 102 29.02 24,184
Introduction 3

Figure 1. Aerial photo of Whitefish (Bardon) Lake, Douglas County, Wis., with its watershed delineated. Surface-water 

and groundwater data-collection sites are identified. 

91°53'30" 91°51'

46°14'

46°12'

Aerial image from U.S. Department of Agriculture, 2006a

Whitefish Lake

Whitefish Lake

EXPLANATION

Near-shore piezometer

and identification number

Surface-water 

drainage basin

Lake-sampling sites

Meteorology and 

lake-stage monitoring site

Outflow monitoring site

6

2

1

3

4

5

19

6

7

8 9

10

18

11

12

20

17

13

16

14

15

Study area

0 0.25 0.5 MILE

0 0.25 0.5 KILOMETER

WISCONSIN

Gordon

Hayward

North Basin

Whitefish Lake

South Basin

Bass Lake

Leader Lake

Deborah

 Lake

Bluegill

Lake
4 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Whitefish Lake is oligotrophic, meaning it does not 

contain an abundance of nutrients and is characterized by 

very clear, deep water (greater than 100 ft), and low primary 

productivity. Whitefish Lake has a two-story fishery with coldwater fish (primarily cisco and trout) and warm-water fish 

(primarily yellow perch and walleye) in the pelagic area of the 

lake (T. Hrabik, University of Minnesota, written commun., 

2007). Oligotrophic seepage lakes are extremely sensitive 

to increases in phosphorus inputs. Only a small increase in 

phosphorus input can increase algal production and organic 

matter that when decomposed may be sufficient to deplete the 

dissolved oxygen in the deep waters of the lake (Newton and 

Jarrell, 1999).

Based on a recent survey of property owners around 

Whitefish Lake (Olson and others, 2006), most of the 100 

property owners (77 percent) have one residential structure. 

The oldest reported residence dates back to 1910, shortly after 

the cutting of the pine forest in the region. A land economic 

inventory (E. Olson, University of Stevens Point, personal 

commun., 2008) found 30 structures on the lake in 1933. 

Based on a Wisconsin Conservation Department lake survey 

map, the number of cottages and permanent homes increased 

to 87 by 1967 (Sather and Johannes, 1973). The number of 

cottages and permanent homes has been relatively stable since 

the 1960s, increasing to about 100 in 2005 (Olson and others, 2006). Several of the residents, however, have replaced 

smaller seasonal structures with larger, year-round structures. 

Residents near Whitefish Lake anticipate further residential 

development near the lake in the coming decades.

In the interest of protecting the water quality of the lake, 

the Whitefish Lake Property Owners Association was formed 

in the 1940’s. This group was originally involved in many 

zoning and political issues. The Association felt the water 

quality in the lake was good, but there was no standard by 

which to judge it or to make future comparisons. Therefore, to 

document the water quality of the lake and develop a baseline 

for future comparisons, the Association began a monitoring 

program with the USGS from 1998 to 2001; the monitoring 

program was partially funded through a WDNR Planning 

Grant and the USGS Cooperative Water Program. Results 

from that study (U.S. Geological Survey, Wisconsin District 

Lake Studies Team, 1999–2002) demonstrated that the lake 

had very low nutrient and chlorophyll a (algae) concentrations, had extremely good water clarity, and that near-surface 

water quality in the North Basin was similar to that in the 

South Basin. As part of political efforts to protect the lake, the 

Whitefish Lake Property Owners Association became a Nonprofit Conservation Organization called the Whitefish Lake 

Conservation Organization (WILCO) in 2000. After the 1998–

2001 USGS study, WILCO members continued to monitor the 

water quality of the lake as part of the WDNR’s Wisconsin 

Citizen Lake Monitoring Network (Wisconsin Department of 

Natural Resources, 2008b). Results from the continued monitoring effort during 2001–04 documented degradation in water 

quality indicated by higher phosphorus and chlorophyll a

concentrations, especially in 2002. During this time, the water 

level in Whitefish Lake, like that of many other lakes in the 

area (Robertson and others, 2009), was higher than normal. To 

determine if the change in water quality documented in Whitefish Lake was a natural phenomenon associated with the high 

water levels during the early 2000s or whether it was caused 

by changes in the watershed, WILCO organized a diverse task 

force of scientists to conduct an interdisciplinary examination 

of the lake. The investigation included an examination of the 

water quality and hydrology of the lake by the USGS, with 

emphasis on examining how changes in hydrology and water 

level affect the water quality of the lake. 

Effects of Changes in Nutrient Loading, Water 

Level, and Climate on Water Quality

Degradation in the water quality (trophic conditions) 

of many lakes is caused by an increase in nutrient loading 

from their watersheds. The effects of nutrient loading (input 

of nutrients over a specified period of time) are sufficiently 

understood, such that empirical eutrophication models have 

been developed that can predict in-lake phosphorus and 

chlorophyll a concentrations and water clarity (Secchi depth) 

from external phosphorus loading (Reckhow and Chapra, 

1983; Cooke and others, 1993; Panuska and Kreider, 2003). 

Most of these models were derived from many lakes with very 

different nutrient loading rates and hydrologic conditions (for 

example, Vollenweider, 1975; Canfield and Bachmann, 1981); 

however, Lathrop and others (1998; 1999) also developed 

response models based on changes in nutrient loading to a 

specific lake––Lake Mendota, Wis. 

Changes in nutrient loading to lakes are usually associated with changes in anthropogenic factors in the watershed, 

such as changes in land use or changes in contributions from 

point sources; however, changes in nutrient loading also occur 

naturally as a function of hydrologic changes. For example, 

more nutrients are usually delivered to a lake during wet years 

than during dry years. Lathrop and others (1998) demonstrated 

that Lake Mendota, Wis., had a larger response to a series of 

wet or dry years than to a single unusual year. Therefore, it 

appears that it can take a few years for a lake to come in equilibrium with inputs from its watershed. After a series of wet 

years, it is also possible that new sources of nutrients develop, 

such as shoreline erosion caused by increased water level, 

increased input from wetland areas around a lake, increased 

nutrient release from nutrient-rich soils, or increased nutrient 

release from old septic systems flooded by rising groundwater 

levels in nearshore areas (Leira and Cantonati, 2008). Persistent fluctuations in precipitation and runoff can, therefore, 

result in changes in water level that can significantly affect the 

water quality of lakes. 

Changes in water levels are natural phenomena for most 

lakes; however, it is believed that global climate change 

can and may have already affected the extent of water-level 

fluctuations in some lakes (Wantzen and others, 2008). Many 

scientists believe, based on results from General Circulation 
Study Methods and Sampling Sites 5

Models, that climate change will either cause systematic 

decreases or increases in hydrologic budgets and water levels, 

or cause water levels to fluctuate more widely than they have 

previously in response to larger fluctuations in precipitation 

and runoff (Mulholland and Sale, 1998; Bates and others, 

2008). It is difficult to predict the effects of climate change 

on a particular lake from large global and regional models 

because a lake’s hydrological cycle involves many interrelated 

components, including precipitation patterns, water temperatures, evaporation rates, groundwater inputs and outputs, and 

surface-water flow rates (Wittman, 2008). It is believed, however, that closed-basin lakes are most vulnerable to changes in 

climate because of their sensitivity to changes in the balance 

of inflows and evaporation (Bates and others, 2008). Results 

from some circulation models indicate that seasonal precipitation patterns will change, resulting in more precipitation in 

winter and less in summer, which in turn may cause groundwater levels to increase and cause a rise in the water levels 

of lakes that have large groundwater inputs. Increases in air 

temperatures, however, may cause an increase in evapotranspiration and cause a decrease in water levels (Wittman, 2008). 

Climate changes can cause increases in air temperatures 

that may affect lake water quality in other ways (Bates and 

others, 2008). Increases in air temperatures will increase 

water temperatures which in turn may stimulate algal blooms. 

Increases in air temperatures will also decrease the period of 

ice cover and, thus, increase the length of the growing season, 

which in turn may result in a longer period of algal and macrophyte growth. The longer growing season, however, may 

result in the available nutrients being depleted and fewer algal 

blooms later in the year. Only a few studies have examined 

how changes in water level affect the water quality of lakes 

(Leira and Cantonati, 2008), and these studies mostly examined changes in common ions and alkalinity (for example, 

Webster and others, 1996; White and others, 2008). 

The recent degradation in water quality of Whitefish Lake 

that has occurred in conjunction with high water levels has 

led to several questions: Are the changes in the lake’s water 

quality caused by changes in the watershed or are they caused 

by changes in water level and the factors causing the changes 

in water levels? Are the recent changes in water level caused 

by global climate change? Are the changes in water level and 

water quality indicative of what may occur in the future? It 

may be difficult to determine if climate change has caused 

the changes in water levels of Whitefish Lake or exactly what 

type of climatic changes may occur in the future; therefore, it 

is important to examine how conditions leading to lower and 

higher water levels affect the water quality of Whitefish Lake.

Several approaches can be used to predict how the water 

quality of a specific lake may respond to hydrologic changes 

and future climate change. One approach examines how the 

lake has responded to past changes in water level, and another 

approach uses numerical models to simulate how the lake 

should respond to specific climate scenarios. A third approach 

is to try to determine how the water quality of the lake 

responds to a range of conditions, such as conditions leading 

to low and high water levels.

Purpose and Scope

The primary purpose of this report is to provide a better 

understanding of what may be causing the apparent degradation in the water quality of Whitefish Lake detected by the 

ongoing Citizen Lake Monitoring Network and, therefore, 

provide information that can be used, in conjunction with 

information from other parts of the interdisciplinary project, to 

better understand and protect this relatively pristine lake in the 

face of increased developmental pressure and possible climatic 

changes. This report describes the water quality of Whitefish 

Lake, quantifies the water and phosphorus budgets for the 

lake based on data collected from November 2004 through 

October 2006, presents the results of model simulations that 

demonstrate the potential effects of changes in phosphorus 

inputs on the lake’s water quality, reconstructs changes in the 

water level in the lake since 1900, and examines the relative 

importance of climatic changes (reflected as changes in water 

level and hydrologic changes in the watershed) and anthropogenic changes in the watershed to the water quality of the lake.

The water-quality data and water and phosphorus 

budgets described in this report improve the understanding 

of the hydrologic system of Whitefish Lake and aid in the 

understanding of how changes in the water levels and nutrient loading affect the water quality of seepage lakes. Results 

of the study, in conjunction with that from other parts of the 

interdisciplinary project, should be useful to local managers in 

the preparation of a comprehensive lake-management plan. In 

addition, results from this study add to the database of lakes 

for which detailed hydrologic, phosphorus loading, and lake 

water-quality information are available to compare with other 

lakes in the region.

Study Methods and Sampling Sites

Personnel from the USGS collected lake, groundwater, 

and meteorological data from 2004 to 2006 as part of this 

study and water-quality data for the lake from 1998 to 2001 as 

part of an earlier study. In addition, water-quality data for the 

lake were collected by volunteers from the community as part 

of the WDNR’s Wisconsin Citizen Lake Monitoring Network 

(Wisconsin Department of Natural Resources, 2008b) from 

2000 to 2008, and by the WDNR from 1973 to 1975 as part 

of a state-wide assessment of lakes (Wisconsin Department 

of Natural Resources, 1974; 1975). Citizen Lake Monitoring 

Network data were obtained from the WDNR’s Web site (Wisconsin Department of Natural Resources, 2008b). All available data, but primarily data on near-surface concentrations of 

total phosphorus and chlorophyll a, and Secchi depths were 

used to describe the water quality of the lake and characterize 
6 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

long-term changes in water quality; however, only data collected from November 1, 2004, to October 31, 2006, were 

used to describe the hydrology and phosphorus inputs to the 

lake. This latter period was divided into two monitoring years 

(MY): November 2004 through October 2005 (hereafter 

referred to as MY 2005) and November 2005 through October 

2006 (hereafter referred to as MY 2006).

Lake-Stage and Water-Quality Monitoring

A continuously recording (at 15-minute intervals) lakestage gage was installed in 2 ft of water just north of a small 

peninsula in the South Basin of Whitefish Lake (fig. 1) and 

operated for the 2-year monitoring period. Lake stage was 

monitored by means of a gas-purge system with a pressure 

transducer. 

Water-quality data for the lake were collected quarterly 

from the South Basin by the WDNR from 1973–75 as part of 

a statewide assessment (Lillie and Mason, 1983). From 2000 

to 2008, Citizen Lake Monitoring volunteers from the community intermittently collected water-quality data including 

total phosphorus and chlorophyll a concentrations, and Secchi 

depths from the South Basin and Secchi depths from the 

North Basin from 2000 to 2008, in accordance with protocols 

described by Betz and Howard (2005). The USGS collected 

data from the deepest locations in the North and South Basins 

(fig. 1) from 1998 to 2001 and from 2005 to 2006 as part of 

this study. From 1998 to 2001, the USGS sampled the lake in 

late winter, spring, and monthly during summer (May through 

September); however, in 2005 and 2006 the lake was not 

sampled during the winter. During each visit, profiles of water 

temperature, dissolved oxygen, specific conductance, and pH 

were collected with a multiparameter data sonde, and water 

clarity was measured with a standard 8-in.-diameter black and 

white Secchi disk (Secchi depth). Lake-water samples were 

collected with a Van Dorn sampler and near-surface samples 

were analyzed for total phosphorus and chlorophyll a concentrations. Near-bottom samples were collected about 1 m 

above the sediment-water interface and were analyzed for total 

phosphorus concentrations. Water samples collected during 

spring were analyzed for nutrients, common ions, and other 

characteristics such as color, turbidity, alkalinity, total dissolved solids, and silica.

The Lake Studies Team of the USGS Wisconsin Water 

Science Center implements a quality-assurance plan that 

involves collecting three types of samples, which include 

blanks, replicates, and spikes, from a subset of the lakes 

studied each year (U.S. Geological Survey, Wisconsin District 

Lake Studies Team, 2006; 2007). During the monitoring 

period, the replicates for total phosphorus were within 

0.006 mg/L over a wide range in concentrations, except for 

one replicate from a eutrophic lake that was within 0.02 mg/L, 

and the replicates for chlorophyll a were within 18 percent 

of each other. Concentrations of total phosphorus and 

chlorophyll a in the blanks analyzed in 2005 and 2006 were 

below the laboratory detection limits of 0.005 mg/L for total 

phosphorus and 0.26 μg/L for chlorophyll a. 

Lake-stage and water-quality data collected by the USGS 

were published in the annual data report series “Water Quality and Lake-Stage Data for Wisconsin Lakes,” water years 

1998–2001 and 2005–06 (U.S. Geological Survey, Wisconsin 

District Lake Studies Team, 1999–2002 and 2006–07).

Lake Classification

One method of classifying the water quality of a lake is 

by computing trophic-state-index (TSI) values based on nearsurface concentrations of total phosphorus and chlorophyll a, 

along with Secchi depths, as developed by Carlson (1977). 

TSI values were developed to place these three characteristics 

on similar scales to allow comparison among lakes. TSI values 

based on total phosphorus concentrations (TSIP), chlorophyll a

concentrations (TSIC), and Secchi depths (TSISD) were computed for each sampling by use of equations 1–3. The individual index values were averaged monthly, and the monthly 

average values were then used to compute average summer 

(May–September) TSI values: 

TSIP = 4.15 + 14.42 [ln total phosphorus 

 (in micrograms per liter)], (1)

TSIC = 30.6 + 9.81 [ln chlorophyll a

 (in micrograms per liter)], and (2)

TSISD = 77.12 – 14.41[ln Secchi depth (in feet)]. (3)

Oligotrophic lakes have TSI values less than 40, a limited 

supply of nutrients, very high clarity, low algal populations, 

and low phosphorus concentrations, and they generally contain 

oxygen throughout the year in their deepest zones (Carlson, 

1977). Mesotrophic lakes have TSI values between 40 and 50, 

a moderate supply of nutrients, moderate clarity, a tendency 

to produce moderate algal blooms, and oxygen is occasionally 

depleted in the deepest zones of the lake. Eutrophic lakes have 

TSI values greater than 50, a large supply of nutrients, and 

severe water-quality problems—such as low clarity and frequent seasonal algal blooms—and oxygen is typically depleted 

in the deeper zones of the lake. 

Lake-Sediment Analyses

A separate paleoecological study of the lake-bottom sediments of Whitefish Lake was done by the WDNR, Bureau of 

Integrated Science Services, to determine the ages of the sediment from specific depths and to quantify historical changes in 

phosphorus concentrations and sedimentation rates in the lake 

(Garrison, 2006). Sediments from deep regions of the North 

and South Basin (fig. 1) were extracted by use of a piston 

coring device in October 2004 and then analyzed to reconstruct the water-quality (phosphorus concentration) history of 

the lake by examining changes in the diatom assemblages at 

different depths in the core. Only information from the core 

collected in the South Basin is discussed in this report.
Study Methods and Sampling Sites 7

Meteorology and Atmospheric Deposition 

Monitoring

A continuously recording (at 15-minute intervals) meteorological station (fig. 2) was installed on the small peninsula 

in the South Basin of Whitefish Lake (fig. 1), and operated 

for the 2-year monitoring period. The meteorological station was installed in a small clearing on the peninsula. The 

meteorological station was equipped with an anemometer, a 

wind direction vane, a total radiation pyranometer, a relative 

humidity sensor, an air-temperature sensor, a precipitation 

tipping bucket that was used during nonfreezing periods, and 

a data recorder. Most of the instruments were 10 to 15 ft off 

the ground. All of the meteorological data were summed into 

daily average or total values. The size of the clearing was large 

enough that all of the instruments, except the anemometer, 

were minimally obstructed. The anemometer was obstructed 

by trees to the west of the station; therefore, wind data from 

the Minong weather station, located 6 mi southwest of the 

lake, were used as the primary data source for wind velocities. 

The Minong weather station is operated by the WDNR (James 

Barnier, Division of Forestry, unpublished data; http://www.

dnr.state.wi.us/forestry/fire/weather/). Data for periods when 

data were missing from the lake meteorological station were 

estimated from data collected at the Minong weather station, 

and missing wind data at the Minong station were estimated 

from data collected at the lake meteorological station. During 

winter, precipitation was estimated by averaging the daily data 

from the National Weather Service (NSW) stations (National 

Climatic Data Center, 2004–2006) at Gordon (about 3 mi 

northeast of the lake) and Solon Springs (about 9 mi north of 

the lake).

Phosphorus deposition on Whitefish Lake was determined from phosphorus concentrations measured in wetfall 

(rain and snow) and phosphorus deposition rates measured in 

dryfall, both of which were measured with a 0.95 ft diameter 

stainless-steel collection bowl mounted on a table about 30 in. 

above ground at the South Basin weather station (figs. 1 and 

2). Netting was placed over the bowl to prevent contamination 

by birds. Local observers serviced the monitoring station and 

collected wet samples and dry samples. Wet samples were collected after a period with rainfall or snowfall. For wet samples, 

the bowl was deployed within a few hours of an imminent 

precipitation event, and the samples were collected as soon 

as possible after the event to reduce evaporation and other 

contamination. Dry samples were those collected after several 

days, usually 7–10 days without precipitation; these samples 

were taken from the bowl by rinsing it twice with 125 mL 

of distilled water. Both types of samples were acidified and 

chilled before they were sent to the laboratory for analysis of 

total phosphorus. The stainless-steel bowl was cleaned with 

phosphorus-free soap before each deployment. Phosphorus 

dryfall deposition rates were computed by determining the 

mass of phosphorus deposited (dry sample concentration x 

0.25 L) per unit area per day of deployment. Samples that 

included insects and other nondepositional material were 

discarded.

Outlet Monitoring

There is no permanent outflow from Whitefish Lake; 

however, intermittent flow does occur into Deborah Lake, a 

small wetland on the southeast side of lake (fig. 1). The outlet 

from Deborah Lake then drains into Leader Lake. Water levels 

(stage) in the stream between Deborah and Leader Lakes at 

South Bass Lake Road were measured by the USGS and a 

local observer whenever flow was present and were used to 

determine flow by use of standard stage-discharge relations 

(Rantz and others, 1982). The phosphorus concentration of 

the water leaving the lake was assumed to be equal to that 

measured in the South Basin of the lake during the period with 

flow. 

Surface-Water Inflow

Daily flows from the area surrounding the lake (surfacewater inflow) were estimated from runoff coefficients of 

0.0015 for grass and developed areas and 0.00015 for forested 

areas (Graczyk and others, 2003), by use of the precipitation 

estimated for the area, and by assuming that 10 percent of 

the watershed was grass and developed areas and 90 percent 

was forested. Phosphorus loads from this nearshore area 

were approximated by multiplying the estimated flow by a 

phosphorus concentration estimated for runoff from the area 

near Whitefish Lake. Because no runoff was observed, the 

concentration in the runoff was estimated from an experiment conducted with soils collected from near the public boat 

landing and from a nearby hillside. About 3 in. of surface soil 

was carefully placed into an 8-ft long eaves trough to resemble 

the area from which it was collected. Distilled water was then 

passed over the soil and allowed to seep through the soil. The 

water that passed over the soil and that flowed through the soil 

(interflow) was collected separately at the downstream end of 

the trough and analyzed for total and dissolved phosphorus. 

The overland flow was in contact with the soil for approximately 2 minutes and the interflow was in contact for at least 

5 minutes. Total phosphorus concentrations were similar for 

both areas; however, overland flow had lower concentrations than interflow; the concentration in overland flow was 

1.6 mg/L and interflow was 3.0 mg/L. Approximately 95 percent of the phosphorus was in the dissolved form for overland 

flow and interflow; therefore, the phosphorus concentrations 

were not significantly affected by particulate matter that was 

washed down the eaves trough.
8

Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Figure 2. Meteorological station installed on the southwest shore of Whitefish Lake, Douglas County, Wis. The location of the meteorological station is identified on figure 1. The atmospheric deposition collector is shown on the right side of the photo. 
Study Methods and Sampling Sites 9

Groundwater Monitoring

Twenty nearshore piezometers (0.5-in. diameter observation wells) were installed around the periphery of the lake 

(fig. 1) to help define areas contributing groundwater to the 

lake, to determine the phosphorus concentration in the groundwater entering the lake, and to help quantify the phosphorus 

loading from groundwater. These piezometers were installed 

approximately 3 ft below the water table, to depths of 4 to 

6 ft. Water levels in the piezometers were measured eight 

times (four times during MY 2005 and MY 2006) and used to 

determine groundwater gradients from the differences in water 

elevation in the piezometers and elevation of the lake surface. 

Dissolved phosphorus concentrations in the groundwater were 

measured once in 2004 (Nov.), twice in 2005 (May and Aug.), 

and once in 2006 (May) for each piezometer. 

All lake, groundwater, and atmospheric-deposition 

samples were analyzed by the Wisconsin State Laboratory of 

Hygiene in accordance with standard analytical procedures 

described in the “Manual of Analytical Methods, Inorganic 

Chemistry Unit” (Wisconsin State Laboratory of Hygiene, 

1993). 

Simulation of Groundwater Flow near Whitefish 

Lake

The two-dimensional, analytic-element, steady-state, 

groundwater-flow modeling computer program, GFLOW 

(Haitjema, 1995) was used to estimate groundwater contributing areas around Whitefish Lake and to estimate exchanges of 

groundwater and lake water. A complete description of the use 

of analytic elements to simulate groundwater flow is beyond 

the scope of this report; however, a brief description is given 

below. A complete discussion of the methods for applying the 

model can be found in Strack (1989) and Haitjema (1995). 

An infinite aquifer is assumed in analytic-element modeling. In GFLOW, the study area (domain) does not require a 

grid or involve interpolation between cells. When an analyticelement model is constructed, features that affect groundwater 

flow, such as surface-water bodies, aquifer characteristics, 

and recharge, are entered as mathematical elements or strings 

of elements. The amount of detail specified for the features 

depends on the distance from the area of interest. Each element is represented by an analytic solution. The effects of 

these individual solutions are added together to arrive at a 

solution for the groundwater-flow system. Because the solution is not confined to a grid, groundwater levels (heads) and 

flows can be computed anywhere in the study area without 

averaging values at specific locations in the model (nodal 

averaging). In the GFLOW model, the analytic elements are 

two dimensional and are used to simulate only steady-state 

conditions (no change in water levels over time). Natural 

groundwater-flow systems are three dimensional; however, 

two-dimensional models can provide reasonable approximations of groundwater flowlines when the lengths of the flowlines are long compared to the aquifer thickness (Haitjema, 

1995, p. 23). In the study area, most groundwater was assumed 

to move through unconsolidated sand deposits that have a 

maximum saturated thickness of 300 ft or less. The lengths of 

the flowlines from recharge areas to discharge areas are typically several thousand feet or more in length.

The GFLOW model for the study area extended up to 

about 30 mi around Whitefish Lake (fig. 3). The geometry 

of the single-layer model included a bottom elevation set at 

850 ft and an average aquifer thickness of about 200 ft, which 

were based on well logs for the study area and additional 

information from Clayton (1984). The sand deposits were 

assumed to have uniform hydraulic conductivity; however, a 

reduced transmissivity zone (transmissivity is the product of 

saturated thickness and hydraulic conductivity) was simulated along the St Croix River downstream of the St. Croix 

Flowage (fig. 3) where the aquifer is very thin and relatively 

impermeable crystalline bedrock is near the land surface 

(Clayton, 1984). In the model, the reduction in transmissivity 

was approximated by reducing the hydraulic conductivity in 

the zone instead of raising the base of the model to improve 

the model’s solution stability. Hydraulic conductivity was 

adjusted as part of the calibration process. Surface-water features such as lakes and streams were simulated using several 

types of linesink elements. The model includes “far-field” and 

“near-field” sources and sinks of water, which are collectively 

referred to as “linesinks” (fig. 3). The far-field area surrounds 

the near-field area of interest. In the far field, streams are 

simulated as coarse linesinks having little or no resistance 

between the surface-water feature and the groundwater-flow 

system. The far field is simulated so that the model explicitly 

defines the regional groundwater-flow field near the area of 

interest. The near field represents the area of interest, and it 

includes Whitefish Lake and other adjacent lakes and streams 

that are in close hydraulic connection with the groundwaterflow system. Base flows measured in near-field streams were 

used to calibrate the model (flux calibration); flows in far-field 

streams were not simulated. Recharge was applied uniformly 

across the model area, while the recharge rate was adjusted 

during model calibration (described below). No high-capacity 

groundwater pumping wells were close enough to Whitefish Lake to have an expected influence on water levels near 

the lake; therefore, no pumping wells were simulated in the 

model. Domestic pumping wells were not included in the 

model because the withdrawal from these wells is widely 

distributed and the withdrawals are relatively small (especially 

where balanced by return flow from septic systems).
10 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Figure 3. Hydrologic features simulated with the GFLOW groundwater-flow model near Whitefish Lake, Douglas County, Wis. 

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Explanation

Whitefish LakeLake-stage target

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Simulated areaLow transmissivityzoneBase-flow target

Ground-waterlevel targets

CityLine sinksCounty boundary

Simulated area

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Namekagon River

St. Cro xi R vi er

Bergen Creek

Figure 3. Hydrologic features simulated with the GFLOW ground-water-flow model near Whitefish Lake, Douglas County, Wis.

0 5 10 2.5 MILES0 5 10 2.5 KILOMETERS

St. Croix

Totagatic River

Flowage

Cranberry

Creek

Gordon

Solon Springs

Wascott BURNETT

DOUGLAS BAYFIELD

WASHBURN SAWYER

ASHLAND

Hayward

Whitefish Lake
Water Quality of Whitefish Lake 11

The stage of Whitefish Lake was simulated as a steadystate value, even though there was a decrease in stage of 

about 0.5 ft during the simulation period. Inputs to the model 

were determined for MY 2005, because the water level of 

the lake changed less dramatically in MY 2005 than in MY 

2006 and the precipitation in MY 2005 was closer to the 

long-term average than in MY 2006. Small cyclic fluctuations 

tend to have minimal effect on regional groundwater flow 

patterns, and the net gains and losses to the groundwater-flow 

system immediately adjacent to the lake are expected to be 

approximated by steady-state conditions for a typical year. 

Whitefish Lake, itself, was simulated with a special type 

of linesink with resistance, called a “lake element,” by use 

of the methodology described by Hunt and others (2003). 

The lake element solves for lake stage based on estimated 

and simulated water inflows to the lake (precipitation and 

groundwater seepage) and outflows from the lake (evaporation 

and groundwater seepage). Small lakes adjacent to Whitefish 

Lake were simulated as high hydraulic conductivity features 

(Hunt and others, 2003). These representations of lakes 

allowed the model to simulate the stage of nearby lakes 

and both the stage and water balance of Whitefish Lake 

directly, which allowed for comparison with measured lake 

levels during calibration. Recharge to the high hydraulic 

conductivity lakes was estimated as total precipitation minus 

evaporation (approximately 5.4 in/yr) from November 2004 

to October 2005 (estimated in the “Hydrology and Water 

Budget” section below). Streambed properties were 

represented by resistance along a linesink. Resistance is 

computed by dividing the bed-sediment thickness by the 

vertical hydraulic conductivity. For this model, resistance 

was set equal to 0.5 ft/(ft/d) for near-field streams and for 

Whitefish Lake. These values indicate a close hydraulic 

connection with the groundwater-flow system and are similar 

to sediment-resistance values used in other nearby GFLOW 

models (Juckem and Hunt, 2007; Hunt and others, 1998; 

Graczyk and others, 2003). The assigned stream widths ranged 

from 10 to 50 ft.

Groundwater levels in 204 wells and elevations in 15 

lakes in the area, base-flow measurements at 4 locations 

on Cranberry and Bergen Creeks, and historical base-flow 

estimates at 7 streamflow gaging stations in the near field 

(fig. 3) were used to calibrate the groundwater-flow model. In 

addition, measured hydraulic gradients from the 20 nearshore 

shallow piezometers around the lake were used to visually 

evaluate the extent of the simulated groundwater capture 

zone along the lake shoreline. The GFLOW model was 

calibrated by varying horizontal hydraulic conductivity and 

groundwater recharge within an expected range until there 

was a reasonable match between measured and simulated 

lake levels, groundwater levels, and base flows for streams in 

the near field (fig. 4). Areal recharge to the groundwater-flow 

system was estimated to be 11 in/yr, and horizontal hydraulic 

conductivity was estimated to be 45 ft/d for the calibrated 

model. These values are within the range of values used to 

simulate groundwater flow in Bayfield County (Lenz and 

others, 2003) and Sawyer County (Juckem and Hunt, 2007). 

The stage of Whitefish Lake was simulated within 0.5 ft of the 

average stage during MY 2005. The mean error (a measure of 

model bias) of all groundwater-level targets is -5 ft (a negative 

value indicates that measured values were less than simulated 

values); the mean absolute difference is 15 ft. These values 

represent about 1–3 percent of the total range in observed 

water levels across the modeled area. Simulated base flows 

were within 0.8 ft3

/s (8 percent) of four synoptic base-flow 

measurements made along Cranberry and Bergen Creeks 

during MY 2005. Simulated base flows were within 8 ft3/s 

(71 percent) of the historical base-flow estimates at the seven 

near-field gaging stations.

Water Quality of Whitefish Lake

Temperature profiles collected in the North and South 

Basins demonstrated that strong thermal stratification developed during summer and thus limited the extent of vertical 

mixing during this period. In both basins, the maximum 

temperature in the upper layer of the lake (epilimnion) reached 

about 26–27°C in early August. Thermoclines in each basin 

developed in May and reached a depth of about 26 to 40 ft in 

July. During summer, near-bottom temperatures reached about 

11–12°C in the North Basin and about 7–8°C in the South 

Basin. Cooler temperatures in the South Basin result from 

that basin stratifying earlier when the water temperatures are 

cooler, and temperatures increase at a slower rate because the 

South Basin is deeper and its hypolimnion has a larger volume 

than the North Basin.

Dissolved oxygen concentrations of about 10–11 mg/L 

were near saturation throughout the lake during nonstratified 

periods in spring and about 8 mg/L throughout the epilimnion during summer. Once stratification developed, dissolved 

oxygen concentrations in the lower layer of the lake (hypolimnion) began to decrease. Near-bottom concentrations reached 

0 mg/L by early-to-mid July in both basins. The maximum 

extent of anoxic conditions (0 mg/L) occurred in September, 

when anoxia occurred from the bottom to about 36 ft from 

the surface in the North Basin and 60 ft from the surface in 

the South Basin. A larger part of the hypolimnion in the North 

Basin became anoxic than in the South Basin, which is a result 

of the smaller hypolimnetic volume in the North Basin.

Dissolved oxygen concentrations throughout the water 

column of the lake were measured in 1973–75, 1998–2001, 

and in 2005–06. Dissolved oxygen profiles collected during 

mid-to-late summer demonstrated interannual variability, but 

no long-term changes in the extent of anoxia in the bottom 

water since the 1970s. 

Whitefish Lake is a soft-water lake, and its alkalinity is 

less than 20 mg/L as calcium carbonate. Specific conductance 

typically is about 35–40 μS/cm throughout the lake; however, 

when the deep areas became anoxic, specific conductance 

increased to about 100 μS/cm near the bottom of the lake. The 

pH in the lake typically was about 7 standard units. 
12 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Figure 4. Measured and simulated heads for the calibrated GLFLOW model for the area near Whitefish Lake, Douglas 

County, Wis. 

Water chemistry in Whitefish Lake is different from that 

in most northwestern Wisconsin lakes, as described by Lillie 

and Mason (1983); the Whitefish Lake has softer water and 

lower concentrations of most constituents than the other lakes. 

Lillie and Mason collected data from a random set of about 

660 Wisconsin lakes, 282 of which were in northwestern 

Wisconsin. The average concentrations for the northwestern 

Wisconsin Lakes were 7 mg/L for calcium, 3 mg/L for magnesium, 4 mg/L for chloride, and 27 mg/L for alkalinity, compared to 4.9, 1.3, 0.9, and 17 mg/L, respectively, for Whitefish 

Lake. The water color in Whitefish Lake ranged from below 

detection to 10 platinum-cobalt units (based on two measurements), which is less colored than the average value of 30 for 

northwestern Wisconsin lakes.

Phosphorus and nitrogen are essential nutrients for 

plant growth, and they are the nutrients that usually limit 

algal growth in most lakes. High nutrient concentrations can 

cause high algal populations (blooms); therefore, increases 

in nutrient inputs can be the cause of accelerated eutrophication (that is, accelerated aging and increased productivity) 

of lakes. Near-surface concentrations of total phosphorus 

less than about 0.012 mg/L indicate oligotrophic conditions, 

whereas concentrations greater than about 0.024 mg/L indicate eutrophic conditions (Carlson, 1977). During MY 2005 

and MY 2006, concentrations ranged from less than the 

0.005‐mg/L detection limit to 0.018 mg/L measured in October 2006 (fig. 5). Near-surface total phosphorus concentrations 

were similar throughout the lake, and they had little seasonality. The near-surface summer (May–September) average 

phosphorus concentration in the South Basin was 0.008 mg/L 

in MY 2005 and 0.010 in MY 2006 (table 2). Therefore, based 

on total phosphorus concentrations, Whitefish Lake would 

usually be classified as oligotrophic.

Since 1998, near-surface total phosphorus concentrations have ranged from less than the 0.005-mg/L detection 

limit to about 0.018 mg/L and were similar between the North 

and South Basins (fig. 5). Concentrations were consistently at 

or near the detection limit in 1998–99, but they increased in 

recent years to about 0.010–0.012 mg/L except for two higher 

concentrations measured in the late summer of 2006. Near-surface, summer average concentrations in both basins gradually 

increased from the detection limit to about 0.008–0.010 mg/L 

in 2006, before decreasing slightly in 2007 and 2008 (table 2). 

900

1,000

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1,500

900 1,000 1,100 1,200 1,300 1,400 1,500

SIMULATED HEAD, IN FEET ABOVE SEA LEVEL

MEASURED HEAD, IN FEET ABOVE SEA LEVEL

Well-construction reports

Nearby lakes

U.S. Geological Survey monitored wells

Whitefish Lake

1:1 Line
Water Quality of Whitefish Lake 13 Figure 5. Near-surface total phosphorus concentrations, chlorophyll a concentrations, and Secchi depths in the South and North Basins of Whitefish Lake, Douglas County, Wis., 1998 to 2008. 

SOUTH BASIN PHOSPHORUS

0.0200.0180.0160.0140.0120.0100.0080.0060.0040.0020.000

TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER

TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER

U.S. Geological Survey > LODU.S. Geological Survey < LODCitizen monitoringSummer average

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 

SOUTH BASIN CHLOROPHYLL a 6

543210

CONCENTRATION, a CHLOROPHYLL 

IN MICROGRAMS PER LITER

 CONCENTRATION, a CHLOROPHYLL 

IN MICROGRAMS PER LITER

U.S. Geological Survey > LODU.S. Geological Survey < LODCitizen monitoringSummer average

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

SOUTH BASIN SECCHI DEPTH

50

4540353025201510

DEPTH, IN FEET

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

NORTH BASIN PHOSPHORUS

0.0200.0180.0160.0140.0120.0100.0080.0060.0040.0020.000

U.S. Geological Survey > LODU.S. Geological Survey < LODSummer average

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

2008

NORTH BASIN CHLOROPHYLL a 6

543210

U.S. Geological Survey > LODU.S. Geological Survey < LOD

Summer average

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

NORTH BASIN SECCHI DEPTH

50

4540353025201510

DEPTH, IN FEET

U.S. Geological Survey Citizen monitoringSummer average

U.S. Geological Survey Citizen monitoringSummer average

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
14 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Table 2. Near-surface summer average (May through September) water quality and trophic-state-index (TSI) values for Whitefish 

Lake, Douglas County, Wis. 

[mg/L milligrams per liter; μg/L, micrograms per liter]

Trophic-state-index values

Year Total phosphorus 

(mg/L)

Chlorophyll a

(μg/L)

Secchi depth 

(feet) Phosphorus Chlorophyll a Secchi depth

1973a

0.020 -- 13.0 47 -- 40

1974b .013 -- 13.0 37 -- 40

1975c .020 -- 13.0 47 -- 40

1998 .005 1.5 24.8 27 35 31

1999 .005 1.0 25.5 26 30 31

2000 .006 1.0 27.1 29 32 30

2001 .006 1.4 26.7 30 34 31

2002 .008 2.6 26.9 33 40 30

2003 .007 1.5 27.6 32 34 29

2004 .007 1.5 27.6 33 34 30

2005 .008 1.4 26.3 33 32 31

2006 .010 1.3 21.2 36 33 33

2007 .006 1.7 28.4 30 35 29

2008 .007 1.1 28.6 32 32 29

Average 1998–99 .0050 1.3 25.2 26 32 31

Average 2002–04 .0073 1.8 27.4 32 36 30

Average 2005–06 .0087 1.3 23.7 34 32 32

Average 2007–08 .0068 1.4 28.5 31 33 29

Average 1998–2007 .0067 1.5 26.2 31 34 30

a

Averages are based on one sample date (Wisconsin Department of Natural Resources) in July (1973).

b

Averages are based on two sampling dates (Wisconsin Department of Natural Resources) in May and August (1974).

c

Averages are based on one sample date (Wisconsin Department of Natural Resources) in May (1975).

Slightly higher concentrations were measured in 2002 and 

2006 compared to other years. In the early 1970s, summer 

average concentrations of 0.013 and 0.020 mg/L were determined from measurements by the WDNR (table 2); however, 

the accuracy of these data were unable to be determined. 

Near-bottom total phosphorus concentrations increased 

after the near-bottom water became anoxic in late summer and 

late winter (fig. 6). Near-bottom concentrations were usually a little higher in the South Basin than in the North Basin. 

Maximum concentrations of about 0.15 to 0.20 mg/L were 

usually measured in late summer (September) and late winter 

(March). The increase in phosphorus concentrations just above 

the bottom indicates that there is a release of phosphorus from 

the deep sediments of the lake (internal phosphorus loading); 

however, because of the strong thermal stratification, this 

phosphorus in the deepest areas is not released into the surface 

water until late fall and near ice break up. 

Maximum annual near-bottom total phosphorus concentrations have been relatively constant from 1998 to 2006, 

reaching about 0.15 to 0.20 mg/L in late summer and late 

winter. Near-bottom total phosphorus concentrations were not 

available in late summer for the 1973–75 samplings; however, 

the concentrations measured in July and early August were 

similar to those collected in similar months in 1998–2006. 

Therefore, there appears to be no long-term trend in near-bottom phosphorus concentrations or internal loading since 1973. 

Near-surface total nitrogen concentrations (computed as 

the sum of Kjeldahl nitrogen and dissolved nitrite plus nitrate) 

were about 0.2 mg/L. Kjeldahl nitrogen represented most of 

the total nitrogen. These values may be a little lower than 

those measured between 1998 and 2001, but all concentrations 

were near the detection limit. 
Water Quality of Whitefish Lake 15

The ratio of the near-surface concentrations of total nitrogen to total phosphorus (N:P ratio) is often used to determine 

the potential limiting nutrient in a lake. The specific value 

of this ratio differs under different ambient conditions such 

as water temperature, light intensity, and nutrient deficiencies (Correll, 1998); however, a ratio greater than about 16:1 

(by weight) usually indicates that phosphorus should be the 

potentially limiting nutrient. The N:P ratios for the 1998–2001 

data ranged from 45:1 to 68:1, and ratios for the 2005–06 

data ranged from 32:1 to 40:1. This indicates that phosphorus 

should typically be the potentially limiting nutrient, and it 

should be the nutrient of concern when management efforts to 

improve or prevent degradation of the water quality in Whitefish Lake are considered.

Chlorophyll a is a photosynthetic pigment found in algae 

and other green plants. Its concentration is commonly used 

as a measure of the density of the algal population in a lake. 

An average concentration less than 2.6 μg/L indicates oligotrophic conditions, and an average concentration greater than 

about 7 μg/L indicates eutrophic conditions. During MY 2005 

and MY 2006, concentrations ranged from less than 1 μg/L to 

5–6 μg/L (fig. 5). The highest concentrations were measured 

in early spring; concentrations during summer were almost 

always less than 3 μg/L. The near-surface summer average 

chlorophyll a concentration in the South Basin was 1.4 μg/L in 

MY 2005 and 1.3 μg/L in MY 2006 (table 2). Based on chlorophyll a concentrations, Whitefish Lake would be classified 

as oligotrophic based on all June through August samples.

Since 1998, near-surface chlorophyll a concentrations 

have ranged from less than 1 μg/L to about 6 μg/L (fig. 5); 

however, concentrations seldom exceeded 3 μg/L during 

summer. Chlorophyll a concentrations may have increased 

slightly since 1998; no concentrations greater than 2 μg/L 

were measured until after 2001. Near-surface, summer average concentrations, however, have remained stable at about 

1.5 μg/L except for the slightly higher concentration of 

2.6 μg/L in 2002 (table 2). 

During MY 2005 and MY 2006, Secchi depths in 

Whitefish Lake ranged from 13 ft in April 2005 to about 

39 ft in July 2005 (fig. 5). Other than the poorer water clarity in spring, little consistent seasonal or spatial variability 

was apparent. The summer average Secchi depth in the 

South Basin was 26.3 ft in MY 2005 and 21.2 ft in MY 2006 

(table 2). Since 1998, Secchi depths have changed very little. 

The poorest clarity was measured in 2006, when the summer 

average depth was 21.2 ft, and the best clarity was measured 

in 2007 and 2008, when the summer average depth was about 

28.5 ft. Secchi depths measured in the lake during 1973–74, 

when the summer average depth was 13 ft, were much shallower than they were after 1998, which is consistent with the 

higher total phosphorus concentrations measured in the early 

1970s. Secchi depths greater than 13 ft indicate oligotrophic 

conditions and those less than 6.6 ft indicate eutrophic conditions; therefore, based on Secchi depths, Whitefish Lake is 

classified as oligotrophic.

All three TSIs, based on near-surface concentrations of 

total phosphorus and chlorophyll a, and on Secchi depths, 

indicate that, in MY 2005 and MY 2006, Whitefish Lake was 

typically oligotrophic except during spring and fall when it 

was classified as mesotrophic based on chlorophyll a concentrations (fig. 7 and table 2). In general, TSI values were consistent among the three parameters except during spring and fall. 

Figure 6. Near-bottom total phosphorus concentrations in the South and North Basins of Whitefish Lake, Douglas County, 

Wis., 1998 to 2006. 

0.000

0.050

0.100

0.150

0.200

0.250

South Basin

North Basin

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 

TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER
16 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Figure 7. Trophic-state-index (TSI) values based on surface concentrations of total phosphorus and chlorophyll a, 

and Secchi depths, in the South Basin of Whitefish Lake, Douglas County, Wis., 1998 to 2008. 

Inferred Lake Water Quality from LakeSediment Analyses

Results of analyses of the sediment cores extracted from 

the deep area of the South Basin in October 2004 were used 

to quantify changes in sedimentation rates and reconstruct 

historical changes in the water quality of Whitefish Lake 

(Garrison, 2006). Only data from the South Basin were used 

because data from the North Basin may have been affected by 

local changes in macrophyte densities (P. Garrison, Wisconsin 

Department of Natural Resources, personal commun., 2007). 

The average annual sedimentation rate for Whitefish Lake 

was 2.7 x 10-6 lb/in2 (0.008 g/cm2), which was the lowest rate 

measured in the 42 lakes examined by the author. The annual 

sedimentation rate steadily decreased from about 2.7 x 

10-6 lb/in2 (0.008 g/cm2

) in 1920 to about 1.7 x 10-6 lb/in2 

(0.005 g/cm2) in 1976, and then increased back to 2.7 x 

10-6 lb/in2 near the top of the core (2002–04). 

Changes in the diatom assemblages in the lake sediments 

were used to infer changes in the phosphorus concentrations 

in the water column of Whitefish Lake from 1800 to 2004 

(fig. 8). The inferred value of 0.013 mg/L for 2002–04 at the 

top of the core overestimated the measured phosphorus concentration of 0.007 mg/L for this period (table 1); therefore, all 

of the values were adjusted for this bias by use of a constant 

percent-bias correction factor (fig. 8). On the basis of changes 

in the diatom assemblages, there has been very little long-term 

change in the phosphorus concentrations in the pelagic area of 

the lake. The adjusted in-lake phosphorus concentrations were

relatively constant at about 0.007 mg/L (similar to the present 

value) from 1800 to 1880, and then increased slightly before 

decreasing to about 0.006 mg/L in 1910. Since 1910, phosphorus concentrations have fluctuated, but they have gradually 

increased to the current value of 0.007 mg/L, which is similar 

to that measured in 1800. 

Hydrology and Water Budget

Because the productivity in Whitefish Lake should be 

limited or potentially limited by the input of phosphorus 

(based on N:P ratios), phosphorus should be the nutrient of 

concern when management efforts to improve or prevent degradation of the water quality of Whitefish Lake are considered. 

Most of the phosphorus entering the lake is transported by 

water inputs; therefore, to quantify phosphorus inputs, it is 

necessary to first quantify the water inputs. Water budgets for 

the lake were quantified for each of the two monitoring years.

The hydrology of Whitefish Lake can be described in 

terms of components of its water budget. The water budget for 

a period of interest may be represented by 

ΔS = (P + SWIn + GWIn) – (E + GWOut+ SWOut), (4)

where ΔS is change in the volume of water stored in the lake, 

which is equal to the sum of the volumes of water entering 

the lake minus the sum of the volumes leaving the lake. Water 

enters the lake as precipitation (P), surface-water inflow (SWIn, 

limited runoff may occur from nearshore areas), and groundwater inflow (GWIn). Water leaves the lake through evaporation 

(E), groundwater outflow (GWOut) and occasionally through 

surface-water outflow (SWOut). Each term of the water budget 

was measured or estimated on a daily basis. Evaporation and 

groundwater often are minor components for many lakes; 

10

20

30

40

50

60

TROPHIC STATE INDEX

Phosphorus 

Chlorophyll a

Secchi depth

Eutrophic

Mesotrophic

Oligotrophic

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Phosphorus, less than detection

Chlorophyll a, less than detection
Hydrology and Water Budget 17

however, they may be very important for a seepage lake, like 

Whitefish Lake. Therefore, evaporation and groundwater 

exchange were examined in detail with numerical models.

Change in Storage

Changes in the storage (volume) of the lake were determined from water-surface elevations measured continuously at 

the lake-stage gage near the southwest side of the lake (fig. 1). 

During the 2-year study period, lake stage declined (fig. 9) 

by 0.44 ft during MY 2005 and 1.10 ft during MY 2006. The 

highest stage recorded was 5.06 ft on June 14–15, 2005, and 

the lowest stage recorded was 3.15 ft on the last day of monitoring, October 31, 2006. Lake stage generally increased from 

late fall through early spring and declined during the summer 

months of both years. To simplify computations of the changes 

in lake volume, an average lake area of 833 acres was used 

in MY 2005 and 823 acres in MY 2006. The amount of water 

stored in the lake decreased by 314 acre-ft during MY 2005 

and by 962 acre-ft during MY 2006 (table 3).

Precipitation

Precipitation on the lake surface during MY 2005 was 

28.4 in. (1,970 acre-ft) and during MY 2006 was 21.8 in. 

(1,500 acre-ft; table 3). Precipitation was 91 percent of the 

long-term average for the period 1971–2000 at Gordon, Wis., 

during MY 2005 and was 70 percent of the long-term average 

during MY 2006. During MY 2005, precipitation totals for 

all months were below normal, except for December, June, 

September, and October (fig. 10). During MY 2006, totals 

for most months were below normal, except for November, 

December, August, and October. 

Figure 8. Estimated changes in summer total phosphorus concentrations based on changes in the diatom 

community in the sediment cores from Whitefish Lake, Douglas County, Wis., (Garrison, 2006), and inferred 

concentrations adjusted to that measured from 2002 to 2004. 

1780

1800

1820

1840

1860

1880

1900

1920

1940

1960

1980

2000

0.004 0.006 0.008 0.010 0.012 0.014 0.016 0.018

INFERRED TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER

YEAR

Garrison, 2006

Adjusted to measured in-lake data
18 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Figure 9. Measured and computed daily water levels (stages) from the full water budget of Whitefish Lake, Douglas 

County, Wis., November 1, 2004, to October 31, 2006. [Altitude of the local datum is 1,029.34 feet above the National 

Geodetic Vertical Datum of 1929.] 

Figure 10. Precipitation at Whitefish Lake, Douglas County, Wis., November 2004 to October 2006, relative to longterm average precipitation at Gordon, Wis. [Altitude of the local datum is 1,029.34 feet above the National Geodetic 

Vertical Datum of 1929.] 

3.0

3.5

4.0

4.5

5.0

11/1/04 3/1/05 7/1/05 11/1/05 3/1/06 7/1/06 11/1/06

STAGE, IN FEET ABOVE LOCAL DATUM

Calculated stage

Measured stage

0

1

2

3

4

5

6

Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct.

PRECIPITATION, IN INCHES

Nov. 2004–Oct. 2005

Nov. 2005–Oct. 2006

1971–2000 average
Hydrology and Water Budget 19

Table 3. Water budget for Whitefish Lake, Douglas County, Wis., for monitoring years 2005 and 2006. 

[MY, monitoring year, November–October; percent, percentage of total]

Budget 

component

MY 2005 

(acre-feet)

MY 2005 

(percent)

MY 2006 

(acre-feet)

MY 2006 

(percent)

Two-year average 

(acre-feet)

Two-year average 

(percent)

Change in storage

Change in storage -314 -962 -638

Inputs to lake

Precipitation 1,970 50.8 1,500 44.0 1,730 47.6

Surface-water inflow .90 .02 .70 .02 .80 .02

Groundwater 1,910 49.2 1,900 56.0 1,910 52.4

Total input 3,880 100 3,400 100 3,640 100

Outputs from lake

Evaporation 1,600 38.0 1,800 41.2 1,700 39.7

Surface-water outflow 20.2 .48 .00 .00 10.1 .24

Groundwater 2,580 61.5 2,580 58.8 2,580 60.1

Total output 4,200 100 4,380 100 4,290 100

Evaporation and Net Groundwater Inflow

Because Whitefish Lake is larger and deeper than many 

nearby lakes, its water temperature increases more slowly 

in spring and decreases more slowly in fall than most other 

lakes; therefore, rates of evaporation from the surface of the 

lake may differ from those of other lakes. In addition, evaporation varies annually depending on meteorological conditions. Therefore, misleading information may result from the 

use of evaporation rates for other nearby lakes or estimation 

of evaporation from nearby evaporation-pan data that are 

typically used to estimate evaporation for small lakes. As an 

alternative for this study, daily evaporation was estimated 

for the 2-year detailed monitoring period by use of a onedimensional hydrodynamic model, the Dynamic Lake Model 

(DLM; McCord and others, 2000; Robertson and others, 

2002). In the process of simulating the hydrodynamics of 

the lake, the model computes detailed energy and hydrologic 

budgets, including the heat transfer associated with evaporation. Therefore, if the detailed energy budget is accurate, then 

the amount of evaporation should be correctly estimated. Net 

groundwater contributions to the lake also can be estimated by 

use of DLM by examining the discrepancies in the modeled 

and measured lake levels. Because Whitefish Lake consists of 

two basins, DLM was used to simulate the hydrodynamics of 

only the South Basin, but the results were extrapolated to the 

entire lake.

DLM is a lake and reservoir model that was modified 

from the DYnamic REservoir Simulation Model, DYRESM 

(Imberger and Patterson, 1981), by McCord and others 

(2000). Both DLM and DYRESM are process-based and 

have been successfully used to simulate vertical changes in 

water temperatures and changes in the timing of ice cover of 

many lakes and reservoirs around the world. DLM is based on 

parameterizations of each of the individual mixing processes, 

so site-specific model calibration is generally not necessary. 

For a more complete description of the DLM model and its 

application to estimate evaporation rates, see Robertson and 

others (2002).

Inputs to DLM included data describing the morphometry 

of the South Basin, meteorological conditions, average light 

extinction in the lake, and initial water temperature and salinity (conductivity) profiles in the lake; inflow and outflow were 

not included in the simulations for Whitefish Lake. Daily average air temperature, vapor pressure, wind speed, and inflow 

characteristics (temperature and specific conductivity/salinity) 

are used in the model, whereas daily total values for inflows, 

outflows, long-wave radiation (or average percentage of clear 

sky), short-wave radiation, rainfall, and snowfall are used. 

Meteorological data were obtained from the meteorological 

station in the South Basin and were supplemented with data 

from the stations operated by the WDNR and the NWS (see 

the “Meteorology and Atmospheric Deposition Monitoring” 

section). An average Secchi depth of 23 ft, the average during 

the open-water period during the 2-year simulation period, 

was used to estimate a light-extinction coefficient of 0.073 ft-1. 

Water temperature and conductivity profiles measured in the 

South Basin on April 20, 2005, were used as the initial conditions for the simulation. Daily evaporation rates, prior to the 

start of the simulation, were assumed to be equal to the average of that estimated in 2005 and 2006 for each calendar day. 

It was assumed that no evaporation occurred when the lake 

was frozen.

To demonstrate that DLM accurately simulated the 

energy balance of the lake, the simulated thermal structure of 

the lake was compared with that measured (fig. 11). During 

the entire simulation period, the model accurately simulated 

the changes in the thermal structure of the lake, specifically 

the onset of stratification, surface and deep temperatures, and 
20 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

the depth of the thermocline; therefore, DLM should have 

correctly simulated the energy and hydrologic balances of 

the lake. Results from the model can also be used to describe 

changes in the thermal structure of the lake during periods 

when the lake was not monitored, such as late fall and winter. 

During the simulation period, the model required an additional 

loss of 0.92 ft3

/s (670 acre-ft/yr) of water to properly simulate 

the water level measured in the lake after the results were 

compensated for the small outflows that occurred in June and 

July 2005. The additional loss of water was assumed to be 

caused by the net loss of water from the lake to groundwater. 

The separation of net inflow into gross inflow and outflow is 

discussed in the “Groundwater Inflow and Outflow” section 

below.

Daily evaporation, computed by DLM from November 1, 

2004, through December 31, 2006, was variable, but it demonstrated a strong seasonal pattern of highest evaporation in 

summer, especially during July and August (fig. 12). The highest daily evaporation was about 0.4 in/d in early August. It was 

assumed that no evaporation occurred when the lake was frozen. The annual evaporation from the surface of the lake was 

23.0 in. (1,600 acre-ft) in MY 2005 and 26.3 in. (1,800 acre-ft) 

in MY 2006 (table 3). These estimates are a little less than the 

average total annual free-surface evaporation estimated for the 

area of approximately 28 in. by Farnsworth and others (1982). 

Surface-Water Inflow

There were no continuously flowing tributaries to the 

lake. Only one channel that could potentially convey surface 

runoff to the lake was identified. This channel was through a 

berm separating the lake from a marsh near the northeast side 

of the lake. No flow was identified through this channel during 

the 2-year study, and, therefore, this area was not included in 

the watershed delineated in figure 1. The only other source of 

surface runoff to the lake is from near-lake hill slopes. Annual 

precipitation and runoff coefficients from Graczyk and others 

(2003) were used to estimate the total surface-water inflow. 

Surface-water inflow is estimated to be 0.9 and 0.7 acre-ft in 

MY 2005 and 2006, respectively (table 3). Although these 

values are very small, the estimated flows may be higher than 

what actually occurred, given the very permeable soils around 

the lake.

Figure 11. Measured and modeled (with the Dynamic Lake Model; McCord and others, 2000) distribution of water temperature, 

April 20, 2005, to December 31, 2006. 

2005 2006

Modeled

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

Jan.

Feb.

Mar.

Apr.

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

Jan.

Feb.

Mar.

Apr.

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

2

8

4

10

12

14

16

18

20

22

24

6

100

60

40

20

0

80

100

60

40

20

0

80

Measured

Missing data Missing data

TEMPERATURE, IN DEGREES CELSIUS

2005 2006

DEPTH, IN FEET DEPTH, IN FEET
Hydrology and Water Budget 21

Figure 12. Daily evaporation from the surface of Whitefish Lake, Douglas County, Wis., November 2004 through December 2006, 

based on output from the Dynamic Lake Model. 

Surface-Water Outflow

There are no continuously flowing outlets from the lake; 

however, flow intermittently occurred into a small channel to 

Deborah Lake and then into Leader Lake (fig. 1). Water levels 

(stages) in the stream (when water was present) between 

Deborah Lake and Leader Lake were used to estimate flow 

from the lake. Flow only occurred in this stream during June 

and July 2005. During these two months, it is estimated that 

20.2 acre-ft of water left the lake (table 3). 

Groundwater Inflow and Outflow

The calibrated GFLOW model was used to define the 

up-gradient groundwater-source areas around Whitefish Lake 

and to estimate the ratio of groundwater inflow and outflow. 

Whitefish Lake is a groundwater flow-through lake: groundwater enters from the east and west sides of the lake and water 

leaves the lake on the north and south ends (fig. 13). The 

groundwater contributing area extends about 0.5 mi to the 

northwest and about 1 mi to the east.

The total annual simulated groundwater flow into Whitefish Lake (GWIn) was 1.77 ft3

/s, and the total annual simulated 

loss from the lake to the groundwater-flow system (GWOut) 

was 2.30 ft3/s. Thus, the net steady-state loss of lake water 

to the groundwater-flow system was 0.53 ft3/s. Although the 

results represent the expected average annual flow rates during 

steady-state conditions (no change in water levels), in actuality, the lake level dropped by 0.44 ft during MY 2005 and by 

1.1 ft during MY 2006. To account for this change in water 

level, and the associated additional loss of lake water during 

the study period, an additional step was performed. That is, net 

annual lake-water outflow was estimated directly in the daily 

water budget calculation (equation 4) and in DLM to match 

the daily change in measured water levels. This updated net 

annual lake-water outflow (0.92 ft3

/s; see the “Evaporation and 

Net Groundwater Inflow” section) was then multiplied by the 

simulated steady-state ratio of groundwater inflow to outflow 

(0.77) from the GFLOW model to compute daily groundwater 

inflow to the lake (2.65 ft3

/s or 1,910 acre-ft) and outflow from 

the lake (3.58 ft3/s or 2,580 acre-ft). This inflow rate was used 

to estimate the phosphorus loading from groundwater. 

The difference between the groundwater inflow rates estimated by the GFLOW model and those estimated with DLM 

and the daily water budget model (equation 4) is attributed to 

calibration of the steady-state GFLOW model to a short calibration period (1 year), when the system was transitioning to 

a drier-than-average condition. That is, changes in lake-water 

storage caused by a declining lake level were incorporated into 

DLM and the water-budget calculation, but they were ignored 

in the GFLOW model. Nevertheless, the ratio of groundwater inflow to lake-water outflow from the GFLOW model is 

expected to remain relatively constant through time because 

groundwater and lake-water levels have similar annual 

fluctuations. 

0.00

0.10

0.20

0.30

0.40

0.50

11/01/04 03/01/05 07/01/05 11/01/05 03/01/06 07/01/06 11/01/06

EVAPORATION, IN INCHES PER DAY
22 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Although this model was considered reasonably calibrated and was sufficient for estimates of groundwater inflow 

to and outflow from Whitefish Lake, local heterogeneities 

that were not simulated with the model may locally alter the 

contributing area to a small degree. In addition, the model was 

calibrated primarily to MY 2005 data; groundwater/lake-water 

interactions for Whitefish Lake during other time periods may 

differ, and such evaluations would likely benefit from recalibration. Also, use of the model for evaluations beyond the 

stated purpose (to estimate groundwater contributing areas 

to the lake and groundwater exchanges with the lake) would 

require reevaluation of the model and likely require recalibration of the model to match new or existing data that correspond to the new purpose. 

Water-Budget Summary

Precipitation and groundwater inflow were the main 

sources of water to Whitefish Lake, and each supplied about 

one-half of the total input during the 2-year study period 

(table 3; fig. 14). Surface runoff supplied less than 1 percent of 

water entering the lake. The total input of water in MY 2005, 

3,880 acre-ft, was more than the 3,400 acre-ft in MY 2006, 

reflecting the near-normal precipitation during MY 2005 and 

much below-normal precipitation in MY 2006. The residence 

time, or the length of time required for water entering the lake 

to completely replace the volume of water in the lake, was 6.2 

and 6.9 years on the basis of the total inflows for MY 2005 

and MY 2006, respectively, or an average residence time of 

6.6 years. 

The total annual outputs of water from the lake were 

greater than total inputs, which resulted in a decrease in storage from the beginning to the end of each monitoring year. 

This amounted to a decrease in lake stage of 1.53 ft or about 

1,290 acre-ft of storage in the lake over the 2-year period. On 

average, groundwater outflow accounted for about 60 percent of the total water output from the lake, and evaporation 

accounted for about 40 percent (table 3; fig. 14).

Figure 13. Simulated groundwater contributing area and flow directions near Whitefish Lake, Douglas County, Wis., from the GFLOW 

groundwater-flow model. 

91°55' 91°47'30"

46°15'

46°10'

EXPLANATION

Flowline

Zone of low 

hydraulic conductivity

Lake

St. Croix

Flowage

Cranberry

Lake

Whitefish

 

Lake

Bergen

Creek

0 0.5 1 MILE

0 0.5 1 KILOMETER
Sources of Phosphorus 23

Figure 14. Water budgets for Whitefish Lake, Douglas County, Wis., for monitoring years (MY) 2005 and 2006. [%, percentage of total 

input or output] 

The quality or accuracy of the water budget was evaluated by comparing the monthly sum of all inputs with the sum 

of all outputs plus the change in storage for the lake, expressed 

in acre-ft (fig. 15). The differences between calculated inputs 

and outputs reflect the cumulative errors in the estimates of all 

of the components in the water budget. The largest monthly 

differences occurred in November 2004 and June 2005, which, 

when expressed as percentages of the total volume of water 

exchanged, were about 16 and 7 percent, respectively. On an 

annual basis, the error was about 1 percent. 

The minimal surface-water inflow into the lake was 

demonstrated by comparison of the measured lake stage with 

that estimated from a mass balance computation that did not 

include surface-water runoff during a 3.92 in. rain event during October 4–5, 2005 (fig. 16). If surface-water inflow from 

the shoreline areas was important, then the measured and computed lake stage would differ. During the rain event, the water 

level of the lake rose 0.310 ft (3.72 in.), which is close to that 

estimated when precipitation, groundwater, and evaporation 

were considered (0.305 ft or 3.67 in.). Therefore, even during 

large rain events, the very permeable soils limited the surfacewater inflow to the lake.

Sources of Phosphorus

To help define where the phosphorus in Whitefish Lake 

originates and how much may be controllable, a detailed 

phosphorus budget was computed on a daily basis for each 

monitoring year. External sources of phosphorus to the lake 

include precipitation, surface-water and groundwater inflow, 

and contributions from septic systems. In addition to these 

external sources, phosphorus can be released from the bottom 

sediments of the lake, which is considered an internal source 

of phosphorus (internal loading). Phosphorus is primarily removed from the lake through deposition to the lake 

sediments. 

Nearshore runoff

0.0%

Nearshore runoff

0.0%

Surface

outflow 0.0%

Precipitation

50.8%

Precipitation

44.0%

Evaporation

41.2%

Evaporation

38.0%

Surface 

outflow 0.5%

Groundwater 

inflow 49.2%

Groundwater 

inflow 56.0%

WATER INPUTS, MY 2005

[3,880 acre-feet]

WATER INPUTS, MY 2006

[3,400 acre-feet]

WATER OUTPUTS, MY 2005 

[4,380 acre-feet]

WATER OUTPUTS, MY 2005 

[4,200 acre-feet]

Groundwater 

outflow 58.8%

Groundwater 

outflow 61.5%
24 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Precipitation 

Atmospheric deposition of phosphorus on Whitefish Lake 

was determined from phosphorus concentrations measured 

in wetfall (rain and snow) and phosphorus deposition rates in 

dryfall measured at the weather station installed on the shore 

of the South Basin of the lake (figs. 1 and 2). Phosphorus 

concentrations measured in 29 precipitation events from both 

years were combined by calendar day (fig. 17). Phosphorus 

concentrations in the precipitation had distinct seasonality 

with lowest concentrations in winter (near the 0.005-mg/L 

detection limit) and highest in early-to-mid summer and late 

fall (near 0.03 mg/L). Monthly average concentrations were 

computed from the individual measurements collected during 

2004–06. Total monthly wetfall deposition was then computed 

by multiplying the monthly average phosphorus concentrations by the estimated precipitation on the lake (fig. 18 and 

table 4). Wetfall deposition was highest during summer when 

concentrations were highest and precipitation was greatest. The total phosphorus contributed by precipitation was 

86.6 lb in MY 2005 and 72.7 lb in MY 2006. From these data, 

an average concentration of 0.009 mg/L was estimated for 

snowfall in winter (December–March) and 0.017 mg/L for 

rainfall in nonwinter months (April–November). The overall 

average annual concentration was 0.016 mg/L. This annual 

concentration is about twice that previously estimated by Rose 

(0.007 mg/L; 1993) for northern Wisconsin. 

Phosphorus deposition rates during 21 periods without 

precipitation (table 4) also had distinct seasonality. The lowest 

daily deposition rates, usually less than 0.1 lb/mi2

, occurred 

in August–March, and the highest rates occurred during 

April–July; the highest daily rate of 1.2 lb/mi2 was in June. 

The highest rates coincided with the release of pollen from 

conifers around the lake. Pollen was observed as distinct 

patches on the shoreline during these periods. The individual 

deposition rates were then combined and used to estimate 

daily dryfall deposition rates for each month. Total monthly 

dryfall deposition (fig. 18) was then determined from the 

number of days without measureable precipitation in each 

month. Because pollen deposition should decrease with the 

distance from the shore, it was assumed that only 33 percent 

of the large increase during March–June actually occurs over 

the entire surface of the lake (this equates to an approximately 

exponential decay to the center of the lake). Therefore, 

approximately 51 lb/yr of phosphorus are deposited on 

Whitefish Lake during periods with no precipitation. 

Figure 15. Monthly total water inputs and outputs plus storage change for Whitefish Lake, Douglas County, Wis., 

based on results from the water-balance model (equation 4). The difference between inputs and outputs indicates the 

cumulative error for all components of the water budget for each month. 

Figure 16. Measured stage in Whitefish Lake, Douglas County, 

Wis., compared to the estimated stage from the water-budget 

model with no overland flow from nearshore areas for the 2-day 

event occurring during October 4–5, 2005. [Altitude of the local 

datum is 1,029.34 feet above the National Geodetic Vertical Datum 

of 1929.] 

0

100

200

300

400

500

600

Inputs

Outputs plus storage change

VOLUME, IN ACRE-FEET

Nov. 04Dec. 04

Jan. 05

Feb. 05

Mar. 05

Apr. 05

May 05

June 05

July 05

Aug. 05

Sept. 05

Oct. 05Nov. 05

Dec. 05

Jan. 06

Feb. 06

Mar. 06

Apr. 06

May 06

June 06

July 06

Aug. 06

Sept. 06

Oct. 06

LAKE STAGE, IN FEET ABOVE LOCAL DATUM

4.1

4.2

4.3

4.4

4.5

10/4/05 

0:00

10/4/05 

6:00

10/4/05

12:00

10/4/05

18:00

10/5/05 

0:00

10/5/05 

6:00

10/5/05

12:00

10/5/05

18:00

Measured stage

Calculated stage
Sources of Phosphorus 25 Figure 17.

A, total phosphorus concentrations measured during wetfall events and 

B, daily dryfall deposition rates measured during 

periods with no precipitation in monitoring years 2005 and 2006, near Whitefish Lake, Douglas County, Wis. Data from both years were combined to estimate the changes in concentrations and loading rates. 

0.040.020.00

AB

0.06

Nov. 1 Jan. 1 May. 1 Aug. 1 Nov. 1

Nov. 1 Jan. 1 May. 1 Aug. 1 Nov. 1

DATE

TOTAL PHOSPHORUS CONCENTRATION, 

IN MILLIGRAMS PER LITER

Sample

Monthly average

1.41.21.00.80.60.40.20.0

DATE

PHOSPHORUS LOADING RATE, 

POUNDS PER SQUARE MILE PER DAY 

Sample100% deposition - conifer area - small lake33% pollen - conifer area - large lake0% pollen - conconifer area
26 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Table 4. Total phosphorus deposition rates for Whitefish Lake, Douglas County, 

Wis., and rates for other types of land cover. (Rates are provided to extrapolate 

results to other areas of northern Wisconsin.) 

[mg/L, milligrams per liter; lb, pound; lb/mi2/d, pounds per square mile per day; %, percent] 

Month/ 

period

Wetfall

Number of 

samples 

into 

averagea 

Average 

concentration 

(mg/L)

Precipitation 

(inches)

Whitefish Lake 

deposition 

(lb)

Nov. 2004 2 0.025 0.80 3.8

Dec. 2004 3 .013 1.28 3.1

Jan. 2005 2 .006 1.41 1.5

Feb. 2005 2 .007 1.12 1.4

Mar. 2005 2 .011 1.59 3.3

Apr. 2005 0 .017 2.09 6.7

May 2005 1 .023 1.95 8.5

June 2005 1 .026 5.64 27.7

July 2005 2 .026 1.03 5.1

Aug. 2005 3 .013 1.37 3.4

Sept. 2005 7 .018 5.05 16.7

Oct. 2005 4 .006 5.10 5.5

Total 29 -- 28.42 86.6

Nov. 2005 2 .025 2.76 13.0

Dec. 2005 3 .013 1.12 2.7

Jan. 2006 2 .006 .99 1.0

Feb. 2006 2 .007 .50 .6

Mar. 2006 2 .011 1.94 4.0

Apr. 2006 0 .017 1.29 4.1

May 2006 1 .023 2.19 9.5

June 2006 1 .026 1.43 7.0

July 2006 2 .026 3.25 16.1

Aug. 2006 3 .013 3.92 9.6

Sept. 2006 7 .018 .99 3.3

Oct. 2006 4 .006 1.45 1.6

Total 29 -- 21.83 72.7

Winter 9 .009 9.94 17.7

Nonwinter 20 .017 40.31 141.6

Annual Total -- -- -- --

Annual 

Average

29 .016 25.12 7.8
Sources of Phosphorus 27

Table 4. Total phosphorus deposition rates for Whitefish Lake, Douglas County, 

Wis., and rates for other types of land covers. (Rates are provided to extrapolate 

results to other areas of northern Wisconsin.)—Continued 

[mg/L, milligrams per liter; lb, pound; lb/mi2/d, pounds per square mile per day; %, percent] 

Month/ 

period

Dryfall Total

Number of 

samples into 

averagea

Number 

of dry 

days

Conifer areas 

(small lake) 

full deposition 

rate 

(lb/mi2

/d)

Conifer areas 

(large lake) 

deposition rate 

33% of pollen 

(lb/mi2

/d)

Nonconifer 

areas 

deposition rate 

no pollen 

(lb/mi2

/d)

Whitefish Lake 

dryfall 

deposition 

(lb)

Whitefish Lake 

total 

deposition 

(lb)

Nov. 2004 3 28 0.058 0.058 0.058 2.10 5.88

Dec. 2004 1 29 .042 .042 .042 1.60 4.74

Jan. 2005 2 27 .020 .020 .020 .69 2.16

Feb. 2005 1 26 .022 .022 .022 .73 2.10

Mar. 2005 2 29 .007 .007 .007 .28 3.57

Apr. 2005 3 28 .462 .257 .154 9.34 16.05

May 2005 3 29 .896 .401 .154 15.12 23.58

June 2005 2 22 .660 .323 .154 9.22 36.90

July 2005 3 29 .133 .133 .133 5.00 10.11

Aug. 2005 0 28 .097 .097 .097 3.54 6.90

Sept. 2005 0 25 .062 .062 .062 2.01 18.76

Oct. 2005 1 27 .027 .027 .058 .93 6.39

Total 21 327 -- -- -- 50.57 137.13

Nov. 2005 3 26 .058 .058 .058 1.93 14.96

Dec. 2005 1 29 .042 .042 .042 1.58 4.33

Jan. 2006 2 29 .020 .020 .020 .74 1.76

Feb. 2006 1 27 .022 .022 .022 .75 1.37

Mar. 2006 2 25 .007 .007 .007 .24 4.25

Apr. 2006 3 27 .462 .257 .154 8.91 13.05

May 2006 3 28 .896 .401 .154 14.44 23.95

June 2006 2 27 .660 .323 .154 11.20 18.19

July 2006 3 28 .133 .133 .133 4.78 20.92

Aug. 2006 0 26 .097 .097 .097 3.25 12.87

Sept. 2006 0 29 .062 .062 .062 2.31 5.58

Oct. 2006 1 28 .027 .027 .058 .96 2.51

Total 21 329 -- -- -- 51.08 123.75

Winter 6 110.5 .023 .023 .023 3.30 20.97

Nonwinter 15 217.5 .299 .169 .109 47.52 189.08

Annual Total -- -- 67.6 39.4 26.1 -- --

Annual 

Average

21 328 .206 .120 .103 5.82 121.60

a

 The number of samples during each month over the 2-year period.
28 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Figure 18. Monthly atmospheric wetfall and dryfall of total phosphorus into Whitefish Lake, Douglas County, Wis., during 

monitoring years (MY) 2005 and 2006. 

Most of the dryfall deposition on the lake in April–June is 

associated with pollen being released from conifers (fig. 18). 

Therefore, it is estimated that the total phosphorus deposited 

on the lake from the atmosphere (wetfall plus dryfall) was 

137 lb in MY 2005 and 124 lb in MY 2006 (tables 4 and 5), 

which is 3.4 times as much as would have been estimated on 

the basis of using only a wetfall concentration of 0.007 mg/L 

from Rose (1993).

The phosphorus concentrations in wetfall and the dryfall 

deposition rates measured at the meteorological station near 

Whitefish Lake can be used to estimate phosphorus deposition 

onto other lakes in northern Wisconsin. Phosphorus in rain and 

snow can be estimated from seasonal average concentrations 

of 0.009 mg/L measured for snow and 0.017 mg/L measured 

for rain if total snowfall and rainfall are measured, or from 

an overall annual average concentration of 0.016 mg/L if just 

total precipitation is measured. The dryfall deposition rates 

can be used to estimate annual phosphorus deposition on 

small lakes where 30–50 percent of the nearby shoreline is 

surrounded by conifers by using the full rate of about 

67.6 lb/mi2

 (fig. 17 and table 4). For large lakes that are similar 

in size to Whitefish Lake and that also are surrounded by a 

high percentage of conifers (about 30–50 percent of the nearby 

shoreline), the rates should be reduced during early summer 

to 33 percent pollen deposition, which results in an annual 

rate of approximately 39.4 lb/mi2. For lakes with few or no 

conifers surrounding the lake, the effects of pollen on the rates 

in April–July should be removed; therefore, the lower curve in 

fig. 17 (0 percent pollen) should be used, which results in an 

annual dryfall deposition rate of 26.1 lb/mi2 (table 4).

Surface-Water Inflow 

The only source of surface inflow is from the nearshore 

areas around the lake, although little signs of overland flow 

were detected except by the public boat landing. The total 

volume of surface runoff to the lake was estimated from daily 

precipitation and published runoff coefficients from Graczyk and others (2003). Because no runoff was observed, the 

concentration in the runoff was estimated from an experiment 

conducted with soils collected near the public boat landing 

and from a nearby hillside. Total phosphorus concentration 

in overland flow was estimated to be 1.6 mg/L and in water 

moving through the upper few inches of the soil was 3.0 mg/L. 

If the maximum concentration of 3.0 mg/L were assumed to 

be the concentration in surface-water inflow, the total phosphorus input from the nearshore areas is estimated to be about 

2–3 lb in MY 2005 and 2006 (table 5). This estimate, although 

very small, is expected to be higher than actual, because little 

runoff would flow horizontally through the upper few inches 

of the soil and very few signs of direct runoff were observed 

except near the boat landing on the southwest shore of the 

lake.

Groundwater

Dissolved phosphorus concentrations in water collected 

from the nearshore piezometers (fig. 1) were used to estimate 

the phosphorus concentration in groundwater entering the 

lake. The concentrations ranged from near the 0.005‐mg/L 

detection limit in piezometers 15 and 18 to 0.08 mg/L 

0

10

20

30

40

PHOSPHORUS LOAD, IN POUNDS

Dryfall

Wetfall

Nov. 04Dec. 04Jan. 05Feb. 05Mar. 05Apr. 05May 05June 05July 05Aug. 05

Sept. 05Oct. 05Nov. 05Dec. 05Jan. 06Feb. 06Mar. 06Apr. 06May 06June 06July 06Aug. 06Sept. 06Oct. 06
Sources of Phosphorus 29

in piezometer 14. The median concentration of all of the 

samples was 0.012 mg/L and the average concentration was 

0.019 mg/L. To estimate the phosphorus input to the lake by 

groundwater, it was assumed that the concentration of groundwater entering the lake was equal to the median concentration measured in the piezometers (0.012 mg/L). An average 

concentration was not used because a few locations may be 

influenced by septic systems, and input from septic systems 

was estimated separately. Thus, the annual input from groundwater was about 63 lb of phosphorus (table 5). 

It was estimated from the nearshore runoff experiments 

that the phosphorus concentration of water seeping through 

the upper few inches of soil quickly increased to about 3 mg/L 

compared to only 0.012 mg/L measured in the groundwater. 

Therefore, most of this phosphorus must be removed by the 

soil in the unsaturated vadose zone prior to reaching the shallow groundwater and being transported to the lake.

Septic Systems

The input of phosphorus from septic systems (M) was 

estimated by use of equation 5 (Reckhow and others, 1980):

M = Es * (number of capita years) * (1 - SR), (5)

where M is a function of a phosphorus export coefficient, 

Es, a soil-retention coefficient, SR, and the number of people 

using the septic systems annually (capita years). In applying equation 5, it was assumed that the most likely value for 

Es was 1.5 lb of phosphorus per capita year. Typical export 

coefficients range from 1.1 lb per capita year (Reckhow 

and others, 1980; Panuska and Kreider, 2003) to 1.8 lb per 

capita year (Garn and others, 1996). Olson and others (2006) 

estimated that 100 properties were around the lake, of which 

89 had septic systems. They also estimated that 25 percent of 

the properties had, on average, 2.5 year-round residents and 

that 75 percent of the properties had, on average, 3.5 threemonth residents. Therefore, the total number of capita years 

was estimated to be 114. A value of 0.7 (70-percent retention 

by the soil) was used for SR. Based on the above assumptions, 

the annual input of phosphorus from septic systems was about 

51 lb; however, not all of the area around the lake contributes 

groundwater to the lake. It is estimated that 70 percent of 

the properties are in areas that contribute groundwater to the 

lake (fig. 13); therefore, the total estimated input from septic 

systems is about 36 lb (table 5). Because inputs from septic 

systems were not directly measured, low and high estimates 

for septic inputs were obtained by applying high and low 

estimates for SR (0.9 and 0.5) in equation 5. The low and high 

estimates for phosphorus inputs from septic systems were 12 

and 60 lb, respectively.

Surface-Water Outflow 

The total phosphorus discharged from Whitefish Lake 

into Deborah Lake through the small outlet on the southeast 

side of the lake was estimated by multiplying the discharge at 

South Bass Lake Road by the average lake phosphorus concentration during the period of flow (0.006 mg/L). Therefore, 

it is estimated that 0.3 lb of phosphorus was discharged from 

the lake in MY 2005 and no phosphorus was discharged in 

MY 2006 (table 5).

Table 5. Phosphorus budget for Whitefish Lake, Douglas County, Wis., for monitoring years 2005 and 2006, and for a series of dry 

and wet years. 

[MY, monitoring year, November–October; all data in pounds or percentage of total] 

Budget 

component

MY 2005 

(pounds)

MY 2005 

(percent)

MY 2006 

(pounds)

MY 2006 

(percent)

2-year 

average 

(pounds)

2-year 

average 

(percent)

Series of 

dry years 

(pounds)

Series of 

wet years 

(pounds)

Inputs to lake

Precipitation 137 57.5 124 55.1 131 56.4 117 162

Surface-water 

inflow

2.9 1.2 2.3 1.0 2.6 1.1 2.6 2.6

Groundwater 

inflow

62.4 26.2 63.0 27.9 62.7 27.0 62.7 62.7

Septic systems 35.9 15.1 35.9 15.9 35.9 15.5 35.9 35.9

Total input 238 100 225 100 232 100 218 264

Outputs from lake

Surface-water 

outflow

.3 100 .0 100 .2 100 .2 .2

Total output .3 100 .0 100 .2 100 .2 .2
30 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Phosphorus-Budget Summary

The average annual load of phosphorus to the lake was 

232 lb, of which 131 lb came from atmospheric deposition 

(56 percent), 63 lb (27 percent) came from groundwater, and 

36 lb (16 percent) came from septic systems (table 5; fig. 19). 

If the high estimates for phosphorus contributions from septic 

systems (60 lb) were used in the budget, then inputs from 

septic systems would increase to about 23 percent of the total 

external phosphorus load, whereas if the low estimate were 

used (12 lb), inputs from septic systems would decrease to 

about 2 percent. The total phosphorus load to the lake ranged 

from 238 lb in MY 2005 to 225 lb in MY 2006. 

In addition to the external sources of phosphorus, the 

increase in phosphorus concentrations just above the bottom 

of the lake (fig. 6) indicates that there is internal phosphorus 

loading to the lake during periods of anoxia. The relatively 

strong thermal stratification that exists when phosphorus is 

released from the deep bottom sediments, however, prevents 

this phosphorus from being released into the surface water 

until late fall and near the time of ice break-up in spring. It 

appears that most of this dissolved phosphorus is rapidly consumed by the biota in the fall or oxidized and removed from 

the water column early in the spring because dissolved and 

total phosphorus concentrations in the lake in April/May are 

usually at or below their respective detection limits, 0.002 and 

0.005 mg/L. Therefore, this additional phosphorus does not 

appear to be available to drive summer productivity and was 

not considered in the phosphorus budget for the lake. There 

appears to be no long-term trend in near-bottom phosphorus 

concentrations; therefore, internal loading of phosphorus does 

not appear to have changed during the period since the lake 

has been monitored.

To determine how the hydrologic and phosphorus loading 

to the lake should vary during a series of dry years and a series 

of wet years, the water and total phosphorus loading to the 

lake was estimated for the 3-year period with the lowest precipitation (1974–76, average precipitation of 22.3 in.) and the 

3-year period with the highest precipitation (1994–96, average 

precipitation of 37.3 in.) since 1915. During these years, phosphorus from wetfall was estimated by multiplying the total 

volume of precipitation by an average phosphorus concentration of 0.016 mg/L, and phosphorus from dryfall was assumed 

to be a constant value of 50.8 lb (table 4). The assumption of a 

constant input from dryfall may be biased slightly high in wet 

years and low in dry years. The total phosphorus from precipitation during the dry years was 117 lb and during the wet years 

was 162 lb. During these years, water and phosphorus from 

the other sources were assumed to be constant: phosphorus 

from surface-water inflow was 2.6 lb, groundwater contributed 

1,910 acre-ft of water and 62.7 lb of phosphorus, and septic 

input was constant at 35.9 lb of phosphorus (table 5). During 

the dry years, the average water loading was 3,450 acre-ft 

and phosphorus loading was 218 lb. During the wet years, the 

average water loading to the lake was 4,500 acre-ft and phosphorus loading was 264 lb. The total water loading to the lake, 

therefore, varies by about 13 percent and the total phosphorus 

loading varies by about 10 percent. If it was assumed that the 

water level of the lake was similar to that at the end of the 

two periods, then the residence time of water in the lake was 

6.8 years during the dry years and 5.5 years during the wet 

years. 

Figure 19. Phosphorus budgets for Whitefish Lake, Douglas County, Wis., for monitoring years (MY) 2005 and 2006. [%, percentage of 

total input.] 

PHOSPHORUS INPUTS, MY 2005

[Total input–238 pounds] 

PHOSPHORUS INPUTS, MY 2006

[Total input–225 pounds]

Groundwater 

26.2%

Precipitation

57.5%

Nearshore 

runoff 1.2%

Septic 

systems

15.1%

Groundwater 

27.9%

Precipitation

55.1%

Nearshore 

runoff 1.0%

Septic 

systems 

15.9%
Simulated Changes in Water Quality in 

Response to Changes in Phosphorus 

Loading and Water Level 

Empirical eutrophication models that relate phosphorus 

loading to specific water-quality characteristics can be used to 

determine how natural and anthropogenic changes in phosphorus loading could modify the water quality of Whitefish 

Lake. These models were developed on the basis of comparisons of hydrologic and phosphorus loading determined for 

many different lake systems, with specific measures describing lake water quality, such as near-surface phosphorus and 

chlorophyll a concentrations, and Secchi depth (Reckhow and 

Chapra, 1983; Cooke and others, 1993; Panuska and Kreider, 

2003). Most of the phosphorus models were derived from 

analyses of many lakes with very different phosphorus-loading 

rates and hydrologic conditions (for example, Vollenweider, 

1975; Canfield and Bachmann, 1981). Most empirical models 

that predict phosphorus concentrations are very sensitive to the 

residence time of water in the lake, and they are not capable 

of accurately simulating water quality in closed-basin seepage 

lakes—lakes without continuous outlets and, therefore, with 

very long residence times. One empirical model that has been 

shown by Robertson and Schladow (2008) to be relatively 

insensitive to residence time is the Canfield and Bachmann 

(1981) natural-lake model. This model has also been shown 

to be one of the best empirical models for predicting the 

phosphorus concentrations of lakes in Wisconsin (Robertson 

and others, 2002; 2005; 2009; Robertson and Rose, 2008). 

Therefore, the Canfield and Bachmann natural-lake model 

(1981; equation 6) was applied to Whitefish Lake to determine 

how changes in phosphorus loading should affect phosphorus 

concentrations in the lake: 

Total phosphorus = L ,

concentration (μg/L) 0.305 *Z (1.62 x (L/Z)0.458 +1/τ) (6)

where

L is the annual phosphorus-loading rate 

(in mg/m2

 = lb/acre x 112.07), 

Z is the mean depth of the lake 

(in meters = ft x 3.2808), and 

τ is the residence time of the water in 

the lake (in years).

In this application, the hydrology and phosphorus loading measured in MY 2005 was used as a base case for other 

comparisons because the water level of the lake changed less 

dramatically than in MY 2006 (fig. 9) and the precipitation in 

MY 2005 was closer to normal than in MY 2006 (table 3).

The total phosphorus concentrations predicted with the 

Canfield and Bachmann model were then used to predict 

chlorophyll a concentrations and Secchi depths through the 

use of Carlson’s (1977) TSI equations (equations 1–3). In 

other words, the chlorophyll a concentrations and Secchi 

depths were computed that yielded a similar TSI value as that 

computed from the predicted total phosphorus concentration. 

There are no true calibration factors when Carlson’s TSI equations are used to estimate chlorophyll a concentrations and 

Secchi depths; however, the output can be adjusted to account 

for model biases by adjusting the results by the percentage of 

bias in the results for the base scenario.

Modeling Approach 

To estimate how the water quality of Whitefish Lake 

should respond to changes in phosphorus loading, 20 scenarios were simulated with the Canfield and Bachmann model 

and Carlson TSI equations (table 6 and fig. 20). Scenario 1 

simulated the conditions for MY 2005 and established a base 

condition (concentration) to which results from the other simulations/scenarios can be compared. Eight simulations (2–9) 

were used to determine the general response of the lake to 

basinwide changes in phosphorus loading: simulated decreases 

in controllable external phosphorus loading by 75, 50, and 

25 percent and increases in controllable external phosphorus 

loading by 25, 50, 75, 100, and 200 percent. Controllable 

external loading includes phosphorus from septic systems and 

surface-water inflow, and it represents only a small part of the 

total phosphorus load to the lake. Two scenarios (10 and 11) 

were then used to evaluate the effects on model results of the 

two estimates made in the phosphorus-budget computations, 

the soil retention estimate used in the computation of inputs 

from septic systems and the percentage of pollen reaching the 

lake in atmospheric dryfall. 

Seven scenarios (12–18) were then used to determine 

how changes in phosphorus loading caused by anthropogenic 

and natural (climatic) changes associated with changes in 

water level could have modified or could modify the water 

quality of the lake in the future. Four scenarios (12–15) were 

used to simulate the effects of anthropogenic changes in the 

watershed: removal of all surface-water inflow, removal of all 

septic inputs, doubling of all septic inputs, and uncontrolled 

development in the watershed. To simulate the effects of 

uncontrolled development in the watershed, it was assumed 

that 25 percent of the watershed would be converted to 

residential areas without stormwater and runoff controls. 

A phosphorus export rate of 0.45 lb/acre was used for this 

development, which is typical for residential areas (Panuska 

and Lillie, 1995). Uncontrolled development would increase 

the phosphorus loading to the lake by 51 lb. Three scenarios 

(16–18) were then used to simulate the effects of natural 

changes (changes in phosphorus loading associated with water 

level/climatic): a decrease in water level by 5 ft, a series of 

three dry years (described earlier), and a series of three wet 

years (described earlier).

Four types of data are required as input into the Canfield 

and Bachmann model: water-quality data (table 2), morphometric data (mean depth), hydrologic data (residence time), 

and nutrient-loading data (table 6). Although loading data are 

summarized for the entire year, this model and the Carlson TSI 

equations simulate water quality only for the growing season 

(May–September); therefore, the water-quality data in table 2 

were used for comparisons. 

Simulated Changes in Water Quality 31
32 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin Table 6. Estimated water quality in Whitefish Lake, Douglas County, Wis., in response to various phosphorus-loading scenarios based on the Canfield and Bachmann natural- lake model (1981) and Carlson (1977) trophic-state-index equations. [mg/L, milligrams per liter; μg/L, micrograms per liter; %, percent] Simulations Scenario number Annual phosphorus load (pounds) Water elevation (feet) Surface area (acres) Mean depth feet) Residence time (years) Predicted total phosphorus concentration (mg/L) Predicted chlorophyll a concentration (μg/L) Predicted Secchi depth (feet) General response Percent change in controllable load - 75% 2 209 4.55 833 29.0 6.1 0.0072 1.2 28.8 - 50% 3 219 4.55 833 29.0 6.1 .0075 1.3 27.9 - 25% 4 229 4.55 833 29.0 6.1 .0077 1.4 27.1 0% - Base 1 238 4.55 833 29.0 6.1 .0079 1.4 26.3 + 25% 5 248 4.55 833 29.0 6.1 .0082 1.5 25.5 + 50% 6 258 4.55 833 29.0 6.1 .0084 1.5 24.9 + 75% 7 268 4.55 833 29.0 6.1 .0086 1.6 24.2 + 100% 8 277 4.55 833 29.0 6.1 .0088 1.7 23.6 + 200% 9 316 4.55 833 29.0 6.1 .0097 1.9 21.6 Sensitivity Less soil retention 10 262 4.55 833 29.0 6.1 .0085 1.6 24.6 100% dryfall 11 274 4.55 833 29.0 6.1 .0088 1.6 23.8 Specific anthropogenic and natural scenarios No surface-water inflow 12 235 4.55 833 29.0 6.1 .0079 1.4 26.5 No septic 13 203 4.55 833 29.0 6.1 .0071 1.2 29.4

Double septic 14 275 4.55 833 29.0 6.1 .0088 1.7 23.7

Uncontrolled buildout 

(25 percent of watershed)

15 289 4.55 833 29.0 6.1 .0091 1.7 22.9

Shallower by 5 feet 16 218 -.45 726 27.9 5.1 .0079 1.4 26.4

Series of dry years 

(ending in 1976)

17 218 3.57 820 28.5 6.8 .0079 1.4 26.3

Series of wet years 

(ending in 1996)

18 264 5.29 837 29.6 5.5 .0081 1.5 25.8
Simulated Changes in Water Quality 33 Figure 20. Measured and simulated average summer near-surface concentrations of 

A, total phosphorus, 

B, Secchi depths, and 

C, chlorophyll a in Whitefish Lake, in 

response to various phosphorus-loading scenarios. Phosphorus concentrations were simulated with the Canfield and Bachmann natural-lake model (1981) and chlorophyll aconcentrations and Secchi depths were simulated with Carlson (1977) trophic-state-index equations. (See table 6 for a description of each scenario.) 

Phosphorus response 0.010

0.0090.0080.007

-100 -50 0 50 100 150 200

PERCENT CHANGE IN CONTROLLABLE 

PHOSPHORUS LOADING 

TOTAL PHOSPHORUS, 

IN MILLIGRAMS PER LITER

24%12%0%-12%

PERCENT CHANGE

Measured

General response Anthropogenic scenarios

EXPLANATION

Natural scenarios

General response No runoff

No septicDouble septicPoor buildout

----Scenarios----- ----Scenarios----- 

----Scenarios----- 

Chlorophyll 

a response

2.01.81.61.41.21.0

-100 -50 0 50 100 150 200

PERCENT CHANGE IN CONTROLLABLE 

PHOSPHORUS LOADING

, A CHLOROPHYLL 

IN MICROGRAMS PER LITER

40%30%20%10%0%-10%-20%-30%

PERCENT CHANGELess septic retention

100% dryfall

Secchi depth response 30

282624222018

-100 -50 0 50 100 150 200

PERCENT CHANGE IN CONTROLLABLE 

PHOSPHORUS LOADING

SECCHI DEPTH, IN FEET

8%0%-8%-16%-23%-31%

PERCENT CHANGE

Reference Reference

Shallower by 5 feetSeries of dry yearsSeries of wet years

A

B

C
34 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Verification and Adjustments for Model Biases

The capability of the Canfield and Bachmann (1981) 

model at simulating phosphorus concentrations in this closedbasin seepage lake was evaluated by inputting the morphometry of the lake and the hydrologic and phosphorus loadings for 

MY 2005 into the model (equation 6) and simulating near-surface total phosphorus concentration. The simulated total phosphorus concentration for MY 2005 (0.0079 mg/L; fig. 20A and 

scenario 1 in table 6) is similar to that measured in the lake 

(0.008 mg/L; table 2). This similarity confirms that the model 

is expected to accurately simulate changes in Whitefish Lake 

in response to changes in phosphorus loading.

Determining how well the Carlson (1977) TSI equations 

simulate chlorophyll a concentrations and Secchi depths in 

Whitefish Lake was accomplished by using the TSI value 

based on the simulated total phosphorus concentration to compute the chlorophyll a concentration and Secchi depth in the 

lake with equations 2 and 3. Given a TSI value of 34.0 (from 

equation 1 with the simulated phosphorus concentration of 

0.0079 mg/L), the predicted chlorophyll a concentration was 

1.42 μg/L and unadjusted predicted Secchi depth was 19.9 ft 

(fig. 20B and 20C). The measured chlorophyll a concentration 

in MY 2005 was 1.4 μg/L, which is similar to that simulated. 

The measured Secchi depth in MY 2005 was 26.3 ft, which 

is 32 percent greater than that predicted with equation 3. The 

discrepancy in Secchi depths indicates that the clarity measured in Whitefish Lake is better than would be expected given 

the measured phosphorus and chlorophyll a concentrations. 

This descrepency may have been caused by the structure of the 

food web and pelagic fish that are present in Whitefish Lake 

(T. Hrabik, University of Minnesota, written commun., 2007) 

in comparison with other lakes with similar phosphorus and 

chlorophyll a concentrations. Because of the large discrepancy 

in measured and simulated Secchi-depth values, all of the 

simulated Secchi-depth values from equation 3 were increased 

by 32 percent. 

Sensitivity of Model Predictions to Assumptions 

in Load Estimations 

The effects of the assumption made in the estimate of 

phosphorus retention by the soil in the computation of septicsystem inputs and the assumption made in the percentage of 

pollen reaching the lake in the estimate of atmospheric dryfall 

were evaluated in scenarios 10 and 11 (table 6): in scenario 

10, the retention coefficient in equation 5 was set to 0.5, and 

in scenario 11, 100 percent of the pollen inputs were used. A 

decrease in the soil retention coefficient from 0.7 (scenario 1) 

to 0.5 (scenario 10) increased the load from septic systems 

from about 36 to 60 lb and increased the overall load by about 

10 percent. This increase in loading resulted in an increase 

in the simulated phosphorus concentration from 0.0079 to 

0.0085 mg/L, an increase in chlorophyll a concentrations from 

1.4 to 1.6 μg/L, and a decrease in the predicted Secchi depth 

from 26.3 to 24.6 ft. An increase in the amount of phosphorus 

in dryfall associated with pollen deposition from 33 percent 

(scenario 1) to 100 percent (scenario 11) increased the phosphorus load from dryfall from 50.6 to 86.4 lb and increased 

the overall load by about 15 percent. This increase in loading 

resulted in an increase in the simulated phosphorus concentration from 0.0079 to 0.0088 mg/L, an increase in the simulated 

chlorophyll a concentrations from 1.4 to 1.6 μg/L, and a 

decrease in the predicted Secchi depth from 26.3 to 23.8 ft. 

Both of these scenarios indicate that the assumptions made 

in constructing the phosphorus budget had a small affect on 

the model predictions. If the higher estimates of loading were 

used, then all of the phosphorus results would be increased 

by only 0.0005 mg/L, chlorophyll a concentrations would 

be increased by about 0.2 μg/L and Secchi depths would be 

decreased by about 2 ft; however, the relative changes from 

the base case would remain the same. 

Response in Water Quality to Basinwide 

Changes in Phosphorus Loading

On the basis of model simulations for basinwide changes 

in controllable phosphorus loading (scenarios 1–9), phosphorus concentrations in the lake should have a linear response 

to a linear change in loading (fig. 20A; table 6). The changes 

in in-lake phosphorus concentrations, on a percentage basis, 

are much smaller than the changes in controllable external 

phosphorus loadings. Changes in in-lake phosphorus concentrations are only about 10 percent of the changes in phosphorus loading. For example, a 50-percent change in controllable 

external phosphorus loading should cause a 5-percent change 

in in-lake phosphorus concentrations. 

Simulated summer average chlorophyll a concentrations 

also had a linear response to changes in controllable external 

phosphorus loading (fig. 20B). The changes in chlorophyll a

concentrations, on a percentage basis, are smaller than the 

changes in external phosphorus loadings. For example, 

a 50-percent change in controllable external phosphorus 

loading causes about a 10-percent change in chlorophyll a

concentrations.

Simulated summer average Secchi depths had a slightly 

less linear response to changes in controllable external phosphorus loading than did total phosphorus and chlorophyll a

concentrations and had a slightly larger response to reductions 

in loading than to increases in loading (fig. 20C). The changes 

in Secchi depths, on a percentage basis, were smaller than 

the changes in external phosphorus loadings. For example, a 

50-percent change in controllable external phosphorus loading 

causes about a 5-percent change in Secchi depths.

The relatively small response of each of these constituents to changes in controllable phosphorus loading is primarily 

because most of the phosphorus presently input into Whitefish 

Lake is from uncontrollable sources, not that Whitefish Lake 

is unresponsive to external loading. In reality, a 100-percent increase in controllable phosphorus loading results 
Historical Changes in Water Levels and Water Quality in Whitefish Lake 35

in an increase in the total phosphorus load of 16.4 percent 

(from 238 lb for the base case to 277 lb) and should cause 

an increase in the total phosphorus concentrations in the lake 

of 11.4 percent, an increase in chlorophyll a of 16.9 percent, 

and a decrease in Secchi depths of 10.1 percent. Therefore, 

changes in phosphorus loading should affect the water quality 

of Whitefish Lake.

Response in Water Quality to Specific 

Anthropogenic and Natural Scenarios

The eutrophication models were used to simulate how 

the summer average concentrations of total phosphorus and 

chlorophyll a, and Secchi depths in Whitefish Lake should 

respond to seven specific anthropogenic and natural scenarios 

with different annual phosphorus loadings and residence times 

of water in the lake (scenarios 12–18 in table 6). The phosphorus concentrations were first estimated with the Canfield and 

Bachmann model and the results were then used to compute 

Carlson TSI values using equation 1. The predicted TSI values 

were then input into equations 2 and 3, and chlorophyll a concentrations and Secchi depths were computed. The simulated 

Secchi depths were then adjusted to account for the original 

32-percent discrepancy in the relation (fig. 18C). 

Four scenarios (12–15) were used to simulate the effects 

of anthropogenic changes in the watershed. Complete removal 

of the phosphorus loading from surface-water runoff (scenario 

12) had very little affect on the lake’s water quality (fig. 20; 

table 6) because this source represented only about 1 percent of the annual phosphorus loading. Complete removal 

of the phosphorus loading from septic systems (scenario 13) 

decreased the phosphorus concentration by 0.0008 mg/L, 

decreased chlorophyll a concentrations by 0.2 μg/L, and 

increased the Secchi depth by 3.1 ft, whereas doubling the 

input from septic systems (scenario 14) increased the phosphorus concentration by 0.0008 mg/L, increased chlorophyll a

concentrations by 0.2 μg/L, and decreased the Secchi depth by 

2.6 ft. Uncontrolled development of about 25 percent of the 

watershed (scenario 15), which includes typical losses from 

septic systems, had the most dramatic affect on water quality 

of the scenarios tested and increased the phosphorus concentration by 0.0012 mg/L, increased chlorophyll a concentrations by 0.3 μg/L, and decreased Secchi depths by 3.4 ft.

Three scenarios (16–18) were used to determine how 

natural/climatic changes, such as changes in phosphorus loading associated with changes in water level, should affect water 

quality (fig. 20; table 6). A decrease in water level by 5 ft from 

that in MY 2005, combined with decreases in phosphorus 

loading caused by precipitation and deposition falling on a 

smaller surface area (scenario 16), had almost no impact on 

the water quality in the lake. This minimal change was caused 

by less phosphorus loading (218 lb) being input into a smaller 

lake (726 acres). Sustained low water levels of about 1-ft 

lower than in MY 2005 caused by a series of dry years with 

less precipitation (and less phosphorus input) on a smaller 

surface area (scenario 17), again had almost no affect on water 

quality. Sustained high water levels of about 0.8 ft higher than 

in 2005 caused by a series of wet years with more precipitation (and more phosphorus input) on a larger surface area 

(scenario 18), however, increased the phosphorus concentrations by 0.0002 mg/L, increased chlorophyll a concentrations by 0.1 μg/L, and decreased Secchi depths by 0.5 ft. 

The relatively small degradation in the water quality in the 

lake following a series of wet years was caused by increased 

precipitation causing an increase in the phosphorus loading by 

about 10 percent, but the higher loads were input into a larger 

lake. Therefore, although high water levels may cause higher 

phosphorus concentrations in the lake, it appears that anthropogenic changes in the watershed could be more important 

than natural/climatic changes in affecting the future water 

quality of the lake.

TSI values based on near-surface concentrations of total 

phosphorus and chlorophyll a, and on Secchi depths indicate 

that Whitefish Lake is usually oligotrophic (fig. 7). On the 

basis of the model simulations, however, the lake is susceptible to degradation if phosphorus loading increases. Although 

results of the simulations in table 6 indicate that the lake will 

remain oligotrophic under the conditions of all of the scenarios 

tested, results from the eutrophication models also indicate 

that with an increase in phosphorus loading of only 180 lb/yr, 

the lake could become mesotrophic. 

Historical Changes in Water Levels 

and Water Quality in Whitefish Lake

Detailed historical water-level (stage) measurements are 

available for only a few lakes in Wisconsin, and they have 

only been made in Whitefish Lake since 1998 except for one 

measurement in 1967 (fig. 21). Since 1998, the water level 

decreased about 2.4 ft, before rising slightly in 2008. Data 

were available, however, to estimate water levels from 1972 to 

2007 in nearby Bluegill Lake, where distances from a reference to the edge of the lake were measured by William and 

Martha Marshand (written commun., 2007). Bluegill Lake is 

a small lake about 0.25 mi east of Whitefish Lake, and it is in 

the same groundwater flow system (figs. 1 and 13). Measurements of distances to the edge of the lake were converted to 

water-level elevations (fig. 21) based on ground-level elevations surveyed in the summer of 2006. Since 1972, the water 

level of Bluegill Lake has gone through at least three cycles 

of rising and falling. The water level in Bluegill Lake tracked 

the changes in water level measured in Whitefish Lake from 

1998 to 2007 (fig. 21); therefore, a numerical relation was 

used to predict historical changes in Whitefish Lake from 1985 

(the year in which continuous annual measurements began at 

Bluegill Lake) until 2003 (when detailed measurement began 

in Whitefish Lake). 
36 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

To estimate how the water level of Whitefish Lake 

changed prior to 1985, a multiple-regression time-series 

relation was developed between the estimated water levels in 

Whitefish Lake from 1985 to 2007 and precipitation measured 

at Gordon, Wis., approximately 3 mi northeast of Whitefish 

Lake. This relation explained 74 percent of the variability in 

the estimated water levels in Whitefish Lake. The water level 

of Whitefish Lake from 1900 to 1984 was then estimated by 

use of the time-series model that related the water level in 

Whitefish Lake to the total annual precipitation at Gordon 

for the present year, the previous 2 years, and the previous 4 years. From 1900 to 1954, precipitation measured at 

Spooner, Wis., approximately 25 mi south of Whitefish Lake, 

was used to fill in any missing precipitation data in the Gordon 

records. The final constructed water levels for Whitefish Lake 

indicate that the water level has experienced about eight cycles 

of rising and falling since 1900 (fig. 21). The changes in water 

level after 1998 are representative of the fluctuations that 

should have occurred since 1900, with fluctuations of about 

3 ft occurring about every 15 years. Large fluctuations in water 

level have been known to occur in Whitefish Lake and have 

affected the area and the behavior of people around the lake. 

The prolonged low-water levels in the early 1930s (fig. 21) 

resulted in the growth of small trees and the use of a road on 

the present-day sand beaches in the southern part of the lake 

(Kinnie Smith, personal commun., 2008). The trees and road 

were later eroded by the higher water levels in the late 1930s 

and 1940s. 

Relative Importance of Anthropogenic 

Changes in the Watershed and 

Changes in Water Level 

One purpose of this study was to understand how natural 

changes in the water level and associated changes in nutrient 

loading affect the water quality of Whitefish Lake in comparison with those caused by anthropogenic changes in the 

watershed. Based on the changes in water level and water 

quality since 1998, it appears that part of the apparent deterioration in water quality between 2002 and 2006 may have 

been caused by the sustained high-water level (and associated 

changes in phosphorus input) of Whitefish Lake because after 

the extended period of high water, phosphorus concentrations 

increased by about 0.003 mg/L and water clarity decreased by 

about 4 to 5 ft. Then, while water levels declined (and phosphorus input declined) in 2007–08, phosphorus concentrations 

decreased and water clarity increased to conditions close to 

those measured around 2000. The changes in measured water 

quality since 1998 are slightly larger than those predicted 

by the eutrophication models if changes only in water level 

and the associated changes in phosphorus loading occurred. 

2.0

3.0

4.0

5.0

6.0

1900 1920 1940 1960 1980 2000

WHITEFISH LAKE STAGE, IN FEET ABOVE LOCAL DATUM 

0

2

4

6

8

10

12

BLUEGILL LAKE STAGE, IN FEET ABOVE 

AN ARBITRARY DATUM

Final constructed water level in Whitefish Lake

Measurements in Whitefish Lake

Measurements in Bluegill Lake

YEAR

Figure 21. Estimated and measured lake stage (water level) in Whitefish Lake, Wis., and Bluegill Lake, Douglas County, Wis., 

1900 to 2008. [Altitude of the local datum is 1,029.34 feet above the National Geodetic Vertical Datum of 1929.] 
Relative Importance of Anthropogenic Changes in the Watershed 37

Therefore, other factors may have contributed to the decrease 

in water quality, such as increased erosion from flooding of 

additional shoreline during the highest water levels that was 

not accounted for in the phosphorus budget, an increase in 

atmospheric deposition, anthropogenic changes in the watershed, or possibly minor changes in the procedures used by the 

laboratory where the analyses were conducted. The improvements in water quality in 2007–08 (fig. 5) that occurred with 

declining water levels indicate that most of the deterioration in 

water quality may have been caused by natural processes. 

The constructed water levels (fig. 21) were compared to 

the adjusted inferred total phosphorus concentrations obtained 

from the sediment core analysis (fig. 8) to determine if the 

small long-term changes in water quality and slightly deteriorated water quality following several years of high water 

levels found in this study are consistent with previous changes 

that are archived in the sediments of the lake (fig. 22). Both 

the current monitoring and modeling study and the results of 

the sediment-core analyses indicate that there has been very 

little long-term change in the water quality of the lake. Results 

from the phosphorus budget indicated that about 85 percent of 

the phosphorus loading to the lake was from natural sources 

and, therefore, little long-term change would be expected. 

The timing of slightly deteriorated water quality following 

several years of high water levels is also roughly consistent 

with results found in the sediment-core study. High total 

phosphorus concentrations, although they were only slightly 

higher than those during periods with low water levels, were 

found near the end of extended periods of high water levels 

from 1900 to 2004. Toward the end of each period of high 

water level, the inferred phosphorus concentration increased 

by about 0.001 mg/L except toward the end of the high water 

levels around 1985; however, no data were available from the 

sediment core for the period from 1984 to 1992. Therefore, it 

appears that the recent degradation in water quality is consistent with high phosphorus concentrations associated with 

sustained high water levels (and increased phosphorus input) 

that may have occurred several times in the past. 

0

1

2

3

4

5

0.008

0.007

0.006

0.005

1900 1920 1940 1960 1980 2000

ESTIMATED LAKE STAGE, IN FEET ABOVE LOCAL DATUM

ADJUSTED INFERRED TOTAL PHOSPHORUS 

CONCENTRATION, IN MILLIGRAMS PER LITER

Constructed Stage

Inferred total phosphorus 

concentrations

YEAR

Figure 22. Adjusted inferred total phosphorus concentrations in the South Basin of Whitefish Lake, Douglas County, Wis., 

compared to the estimated lake stage (water level) in Whitefish Lake, 1900 to 2008. [Altitude of the local datum is 1,029.34 feet 

above the National Geodetic Vertical Datum of 1929.]
38 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Summary and Conclusions

Whitefish Lake is an oligotrophic, soft-water, seepage lake in northwestern Wisconsin that is classified by the 

WDNR as an Outstanding Resource Water because of its clear 

waters and diversity of plants and wildlife. Data collected 

as part of the ongoing monitoring program conducted by the 

local community demonstrated that the pelagic water quality 

of the lake began to degrade, shown by increases in phosphorus and chlorophyll a concentrations, around 2000–02. The 

decrease in water quality, however, coincided with relatively 

high water levels in the lake. To provide a better understanding 

of what may have been causing the apparent degradation in 

water quality, and therefore, provide information for management of the lake should development increase or the climate 

change, the USGS conducted a detailed study during 2004–08. 

The goals of the study were to describe the lake’s past and 

present water quality, construct water and phosphorus budgets, 

simulate the potential effects of changes in phosphorus inputs 

on the lake’s water quality, analyze changes in the water level 

in the lake since 1900, and relate the importance of changes in 

water level (and associated changes in phosphorus input) and 

anthropogenic changes in the watershed to the water quality of 

the lake.

Since 1998, summer average total phosphorus concentrations have increased from near the 0.005-mg/L detection limit 

to about 0.010 mg/L in 2006, before decreasing slightly in 

2007–08. From 1998 to 2008, near-surface chlorophyll a concentrations and Secchi depths have remained relatively stable 

at about 1.5 μg/L and 26 ft, respectively. Therefore, Whitefish 

Lake would typically be classified as oligotrophic.

Because the productivity in Whitefish Lake should be 

limited by phosphorus, it should be the nutrient of concern 

when management efforts to improve or prevent degradation 

in the lake’s water quality are considered. Most phosphorus enters the lake with water inputs; therefore, both water 

and phosphorus budgets were constructed. Precipitation and 

groundwater inflow were the predominant sources of water, 

each supplying about one-half of the total input, whereas 

surface-water inflow supplied less than 1 percent of total 

input. Because Whitefish Lake has little contributions from the 

watershed, it was believed that much of the phosphorus reaching the lake came from the atmosphere; therefore, wetfall and 

dryfall phosphorus input from the atmosphere were measured 

in this study. The amount of phosphorus input from the atmosphere was about 3 times higher than that computed based on 

previous wetfall phosphorus concentrations. The concentrations and deposition rates estimated at Whitefish Lake may be 

used to estimate atmospheric loading in future lake studies. 

The average annual load of phosphorus to the lake was 232 lb, 

of which 131 lb (56 percent) came from atmospheric deposition, 63 lb (27 percent) came from groundwater, and about 

36 lb (16 percent) came from septic systems. To determine 

how the hydrologic and phosphorus loading to the lake have 

varied with fluctuations in water level, water and phosphorus 

budgets were constructed for a series of dry years (low water 

levels) and wet years (high water levels). The total water input 

into the lake ranged by only 13 percent and the total phosphorus loading ranged by 10 percent. 

Results from the Canfield and Bachmann eutrophication 

model and Carlson TSI equations demonstrated that changes 

in controllable phosphorus loading have a linear relationship 

with phosphorus and chlorophyll a concentrations and Secchi depths in the lake; however, the changes should be only 

10 to 20 percent of the changes in controllable phosphorus 

loading. In other words, a 50-percent increase in controllable 

external phosphorus loading should cause a 5- to 10-percent 

change in water quality. The response is small not because 

the lake is unresponsive to external loading, but because most 

of the phosphorus loading to the lake comes from uncontrollable sources. A 16.4-percent increase in total phosphorus 

loading caused total phosphorus concentrations to increase 

by 11.4 percent, chlorophyll a concentrations to increase by 

16.9 percent, and the Secchi depths to decrease by 10.1 percent. Therefore, changes in phosphorus loading should affect 

the water quality of the lake.

Seven scenarios were used to simulate the effects of 

anthropogenic and natural/climatic (water level and the associated changes in phosphorus input) changes on water quality, 

which demonstrated that: surface-water inflow (runoff) presently has little effect on the lake, changes in the inputs from 

septic systems and potential development in the watershed 

could have a large effect on water quality, decreases in water 

level (and associated decreases in phosphorus input) has little 

effect on water quality, and sustained high water levels (and 

associated increases in phosphorus input) following several 

wet years could cause a small degradation in water quality. 

Although increases in phosphorus input associated with high 

water levels may degrade water quality, it appears that anthropogenic changes in the watershed may be more important than 

natural/climatic changes in affecting the future water quality 

of the lake.

Reconstructed water levels of Whitefish Lake indicated 

that the changes in water level since 1998 are representative of 

fluctuations that have occurred since 1900, with fluctuations 

of about 3 ft occurring about every 15 years. A comparison 

of constructed water levels with the inferred total phosphorus 

concentrations obtained from sediment core analyses indicated that there has been very little long-term change in water 

quality and that there is a slight deterioration in water quality 

following sustained high water levels. Therefore, it appears 

that the recent degradation in water quality is consistent with 

what may have occurred several times in the past associated 

with sustained high water levels. 

Whitefish Lake is presently a relatively pristine lake, 

and it is classified by the WDNR as an Outstanding Resource 

Water primarily because of the small input of phosphorus 

from its watershed. Although the recent degradation in water 

quality appears to be associated primarily with increases in 

phosphorus input associated with high water levels, the lake is 
References Cited 39

still susceptible to degradation associated with small changes 

in its watershed. Because of the small amount of phosphorus 

that is presently input into the lake, what many would consider 

a small increase in phosphorus input could have a large effect 

on the lake’s water quality. Therefore, management actions to 

minimize future phosphorus input into this lake are important 

for maintaining the quality of its water. 

References Cited

Bates, B.C., Kundzewicz, Z.W., Wu, S., and Palutikof, J.P., 

eds., 2008, Climate change and water: Geneva, Technical 

Paper of the Intergovernmental Panel on Climate Change, 

IPCC Secretariat, 210 p.

Betz, C.R., and Howard, P.J., 2005, Wisconsin citizen lake 

monitoring training manual: Madison, Wis., Wisconsin 

Department of Natural Resources, PUB–SS–1009, 54 p.

Canfield, D.E., and Bachmann, R.W., 1981, Prediction of 

total phosphorus concentrations, chlorophyll-a, and Secchi 

depths in natural and artificial lakes: Canadian Journal of 

Fisheries and Aquatic Sciences, v. 38, p. 414–423.

Carlson, R.E., 1977, A trophic state index for lakes: 

Limnology and Oceanography, v. 22, p. 361–369.

Clayton, Lee, 1984, Pleistocene geology of the Superior 

region, Wisconsin: Wisconsin Geological and Natural 

History Survey, Information Circular no. 46, 40 p.

Cooke, G.D., Welch, E.B., Peterson, S.A., and Newroth, P.R., 

1993, Restoration and management of lakes and reservoirs 

(2d ed.): Boca Raton, Fla., Lewis Publishers, 548 p. 

Correll, D.L., 1998, The role of phosphorus in the eutrophication of receiving waters—A review: Journal of Environmental Quality, v. 27, p. 261–266.

Farnsworth, R.K., and Thompson, E.S., 1982, Mean monthly, 

seasonal, and annual pan evaporation for the United States: 

National Oceanic and Atmospheric Administration 

Technical Report NWS 34, 82 p.

Garn, H.S., Olson, D.L., Seidel, T.L., and Rose, W.J., 

1996, Hydrology and water quality of Lauderdale Lakes, 

Walworth County, Wisconsin, 1993–94: U.S. Geological 

Survey Water-Resources Investigations Report 96–4235, 

29 p. 

Garrison, P.J., 2006, Paleoecological study of Whitefish 

Lake, Douglas County: Wisconsin Department of Natural 

Resources, Bureau of Integrated Science Services, 

PUB–SS–1028, 22 p.

Graczyk, D.J., Hunt, R.J., Greb, S.R., Buchwald, C.A., and 

Krohelski, J.T., 2003, Hydrology, nutrient concentrations 

and nutrient yields in nearshore areas of four lakes in northeastern Wisconsin, 1999–2001: U.S. Geological Survey 

Water-Resources Investigations Report 03–4144, 64 p.

Haitjema, H.M., 1995, Analytic element modeling of groundwater flow: San Diego, Calif., Academic Press, 394 p.

Homer, Collin, Dewitz. J., Fry, J., Coan, M., Hossain, N., 

Larson, C., Herold, N., McKerrow, A., Van Driel, J.N., 

and Wickham, J., 2007, Completion of the 2001 National 

Land Cover Database for the conterminous United States: 

Photogrammetric Engineering and Remote Sensing, v. 73, 

p. 337–341. 

Hunt, R.J., Anderson, M.P., and Kelson, V.A., 1998, Improving a complex finite-difference ground water flow model 

through the use of an analytic element screening model: 

Ground Water, v. 36, no. 6, p. 1011–1017.

Hunt, R.J., Haitjema, H.M., Krohelski, J.T., and Feinstein, 

D.T., 2003, Simulating lake-ground water interactions—

Approaches and insights: Ground Water, v. 41, no. 2, 

p. 227–237.

Imberger, J., and Patterson, J.C., 1981, A dynamic reservoir 

simulation model, DYRESM-5, in Fischer, H.B., ed., 

Transport models for inland and coastal waters: New York, 

Academic Press, p. 301–361.

Juckem, P.F., and Hunt, R.J., 2007, Simulation of the shallow ground-water-flow system near Grindstone Creek and 

the community of New Post, Sawyer County, Wisconsin, 

U.S. Geological Survey Scientific Investigations Report 

2007–5014, 39 p.

Lathrop, R.C., Carpenter, S.R., and Robertson, D.M., 1999, 

Summer water clarity responses to phosphorus, Daphnia 

grazing, and internal mixing in Lake Mendota: Limnology 

and Oceanography, v. 44, p. 137–146.

Lathrop, R.C., Carpenter, S.R., Stow, C.A., Soranno, P.A., 

and Panuska, J.C., 1998, Phosphorus loading reductions 

needed to control blue-green algal blooms in Lake Mendota: 

Canadian Journal of Fisheries and Aquatic Sciences, v. 55, 

p. 1169–1178.

Leira, Manel, and Cantonati, M., 2008, Effects of waterlevel fluctuations on lakes—An annotated bibliography: 

Hydrobiologia, v. 613, p. 171–184.

Lenz, B.N., Saad, D.A., and Fitzpatrick, F.A., 2003, Simulation of ground-water flow and rainfall runoff with emphasis 

on the effects of land cover, Whittlesey Creek, Bayfield 

County, Wisconsin, 1999–2001: U.S. Geological Survey 

Water-Resources Investigations Report 2003–4130, 47 p.
40 Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin

Lillie, R.A., and Mason, J.W., 1983, Limnological characteristics of Wisconsin lakes: Wisconsin Department of Natural 

Resources Technical Bulletin 138, 116 p.

McCord, S.A., Schladow, S.G. and Miller, T.G., 2000, Modeling artificial aeration kinetics in ice covered lakes: Journal 

of Environmental Engineering, v. 26, no. 1, p. 21–31.

Mulholland, P.J., and Sale, M.J., 1998, Impacts of climate change on water resources—Findings of the IPCC 

regional assessment of vulnerability for North America: 

Water Resources Update, Universities Council on Water 

Resources, Issue 112, p. 10–15.

National Climatic Data Center, 2004–2006, Climatological 

data: Asheville, N.C., National Oceanic and Atmospheric 

Administration [published monthly].

Newton, B.J., and Jarrell, W.M., 1999, A procedure to estimate 

the response of aquatic systems to changes in phosphorus and nitrogen inputs: U.S. Department of Agriculture, 

National Water and Climate Center, NWCC–TN–99–2, 

37 p.

Olson, Eric, Demorest, K., and Slifka, K., 2006, Whitefish 

Lake watershed 2005 interviews with property owners: 

University of Wisconsin Stevens Point, University of 

Wisconsin Extension, 16 p.

Panuska, J.C., and Kreider, J.C., 2003, Wisconsin lake 

modeling suite program documentation and user’s manual, 

Version 3.3 for Windows: Wisconsin Department of Natural 

Resources PUBL–WR–363–94, 32 p., accessed April 23, 

2009, at http://www.dnr.state.wi.us/org/water/fhp/lakes/

laketool.htm

Panuska, J.C., and Lillie, R.A., 1995, Phosphorus loadings 

from Wisconsin watersheds—Recommended phosphorus 

export coefficients for agricultural and forested watersheds: 

Wisconsin Department of Natural Resources Research 

Management Findings, 38, Publ–RS–738, 8 p.

Rantz, S.E., and others, 1982, Measurement and computation 

of streamflow—Volume 1, measurement of stage and discharge: U.S. Geological Survey Water-Supply Paper 2175, 

284 p.

Reckhow, K.H., Beaulac, M.N., and Simpson, J.T., 1980, 

Modeling phosphorus loading in lake response under uncertainty—A manual and compilation of export coefficients: 

U.S. Environmental Protection Agency EPA–440/5–80–011.

Reckhow, K.H., and Chapra, S.C., 1983, Engineering 

approaches for lake management, volume I—Data analysis 

and empirical modeling: Boston, Butterworths Publishers, 

340 p.

Robertson, D.M., Goddard, G.L., Mergener, E.A., Rose, W.J., 

and Garrison, P.J., 2002, Hydrology and water quality of 

Geneva Lake, Walworth County, Wisconsin, U.S. Geological Survey Water-Resources Investigations Report 02–4039, 

73 p.

Robertson, D.M., and Rose, W.J., 2008, Water quality, hydrology, and simulated response to changes in phosphorus 

loading of Butternut Lake, Price and Ashland Counties, 

Wisconsin, with special emphasis on the effects of internal 

phosphorus loading in a polymictic lake: U.S. Geological 

Survey Scientific Investigations Report 2008–5053, 46 p.

Robertson, D.M., Rose, W.J., and Fitzpatrick, F.A., 2009, 

Water quality and hydrology of Silver Lake, Barron County, 

Wisconsin, with special emphasis on responses of a terminal 

lake to changes in phosphorus loading and water level: 

U.S. Geological Survey Scientific Investigations Report 

2009–5077, 38 p.

Robertson, D.M., Rose, W.J., and Saad, D.A., 2005, Water 

quality, hydrology, and phosphorus loading to Little St. Germain Lake, Wisconsin, with special emphasis on the effects 

of winter aeration and ground-water inputs: U.S. Geological 

Survey Scientific Investigations Report 2005–5071, 36 p.

Robertson, D.M., and Schladow, S.G., 2008, Response in the 

water quality in the Salton Sea to changes in phosphorus 

loading—An empirical modeling approach: Hydrobiologia, 

v. 604, p. 5–19.

Rose, W.J., 1993, Water and phosphorus budgets and trophic 

state, Balsam Lake, northwestern Wisconsin, 1987–89: 

U.S. Geological Survey Water-Resources Investigations 

Report 91–4125, 28 p.

Sather, L.M., and Johannes, S.I., 1973, Surface water 

resources of Douglas County: Wisconsin Department of 

Natural Resources, 161 p.

Shaw, Byron, Mechenich, C., and Klessig, L., 2002, Understanding lake data: Madison, Wis., University of Wisconsin 

Extension Service, RP–09–96–3M–275, 20 p., accessed 

April 23, 2009, at http://www.dnr.state.wi.us/org/water/fhp/

lakes/under/.

Strack, O.D.L., 1989, Groundwater mechanics: Englewood 

Cliffs, N.J., Prentice-Hall, 732 p.

U.S. Department of Agriculture, 2006a, National Agricultural 

Imagery Program (NAIP) Digital orthorectified images 

(DOQ), Minnesota, 2006,(interim): Salt Lake City, Utah, 

U.S. Department of Agriculture, Farm Service Agency, 

Aerial Photography Field Office, accessed September 15, 

2008, at http://www.lmic.state.mn.us/chouse/metadata/

naip06.html#full
References Cited 41

U.S. Department of Agriculture, 2006b, Soil survey 

of Douglas County, Wisconsin: Natural Resources 

Conservation Service, 274 p. + maps, accessed April 23, 

2009, at http://soildatamart.nrcs.usda.gov/Manuscripts/

WI031/0/Douglas_WI.pdf 

U.S. Geological Survey, Wisconsin District Lake Studies 

Team, 1999–2002 and 2006–07, Water quality and lakestage data for Wisconsin lakes, water years 1998–2001 and 

2005–2006: U.S. Geological Survey Open-File Reports 

99–98, 00–89, 01–86, 02–135, 2006–1080, and 2007–1173 

[published annually]. 

Vollenweider, R.A., 1975, Input-output models, with special 

reference to the phosphorus loading concept in limnology: 

Schweizerische Zeitschrift fur Hydrologie, v. 37, p. 53–84.

Wantzen, K.M., Rothhaupt, K.O., Mortl, M., Cantonati, M., 

Toth, L.G., and Fischer, P., 2008, Ecological effects of 

water-level fluctuations in lakes—An urgent issue: 

Hydrobiologia, v. 613, p. 1–4.

Webster, K.E., Kratz, T.K., Bowser, C.J., Magnuson, J.J., and 

Rose, W.J., 1996, The influence of landscape position on 

lake chemical responses to drought in northern Wisconsin: 

Limnology and Oceanography, v. 41, p. 977–984.

White, M.S., Xenopoulos, M.A., Hogsden, K., Metcalfe, R.A., 

and Dillion, P.J., 2008, Natural lake level fluctuation and 

associated concordance with water quality and aquatic communities within small lakes of the Laurentian Great Lakes 

region: Hydrobiologia, v. 613, p. 21–31.

Wisconsin Department of Natural Resources, 1974, Water 

quality of selected Wisconsin lakes 1973–74: Madison, Wis. 

186 p.

Wisconsin Department of Natural Resources, 1975, Water 

quality of selected Wisconsin lakes 1974–75, Madison, Wis. 

191 p.

Wisconsin Department of Natural Resources, 1999, Wisconsin lakes: Madison, Wis., LAKES–PUB–FM–800 99Rev, 

182 p.

Wisconsin Department of Natural Resources, 2008a, 

Outstanding and exceptional resource waters, accessed 

September 15, 2008, at http://dnr.wi.gov/lakes/CLMN/.

Wisconsin Department of Natural Resources, 2008b, 

Wisconsin Citizen Lake monitoring network, accessed 

April 23, 2009, at http://dnr.wi.gov/lakes/CLMN/.

Wisconsin State Laboratory of Hygiene, 1993, Manual of 

analytical methods, inorganic chemistry unit: Madison, 

Wisconsin State Laboratory of Hygiene, Environmental 

Sciences Section, revised November 1993 [variously paginated].

Wittman, Steven, 2008, Climate change in the Great Lakes 

region, starting a public discussion: University of Wisconsin 

Sea Grant Institute/University of Wisconsin Board of 

Regents, 83 p.

Young, H.L., and Hindall, S.M., 1973, Water resources of 

Wisconsin—St. Croix River Basin: U.S. Geological Survey 

Hydrologic Investigations Atlas HA-451, scale 1:1,000,000, 

4 sheets. 
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Robertson and others—Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin—Scientific Investigations Report 2009–5089

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