Assessment of the Hydrology, Water Quality, and Phosphorus loading of Whitefish Lake, Douglas County, Wisconsin
Project Number: 9KB37
Project Chief: Dale Robertson
Project Topics: Douglas County, Lake, Whitefish, chlorophyll, phosphorus, oligoprophic
Cooperators: Town of Wascott
Period of Project: October 2007-current
Whitefish Lake area residents want to develop a management plan that guides activities in and near the lake in a manner that protects the present high quality of water in the lake. In order to focus management efforts most efficiently the Lake Studies team will quantify sources of water and phosphorus entering the lake.
Problem
Whitefish Lake is a high-quality oligoprophic seepage lake. Although monitoring data do not indicate serious problems, recent data show increased concentrations of phosphorus and chlorophyll a. It is possible that the slight degradation in water quality is associated with climatically-caused higher water levels in recent years. Lake area residents want to develop a management plan that guides activities in and near the lake in a manner that protects the present high quality of water in the lake. In order to focus management efforts most efficiently it is necessary to quantify sources of water and phosphorus entering the lake. Although seepage lakes are the most common type of lake in Wisconsin, most comprehensive lake water- and phosphorus-budget studies have been conducted on conducted on drainage lakes. Data for seepage lakes (especially oligotrophic seepage lakes) are needed to enhance the understanding of seepage lake water-quality response to phosphorus loading.
Objectives
Objectives are to (1) develop a dedailed water budget by measuring all major inflow and outflow sources and estimating minor sources, (2) determine ground-water contributing areas and flow paths from recharge to discharge into the lake, (3) determine a detailed phophorus budget by quantifying loading associated with each water inflow and outflow source, (4) evaluate lake water quality relative to longer-term trends and to measured loading through the use of selected models in WiLMS and the Wisconsin Department of Natural Resources Seepage Lake Model, (5) use the calibrated model or models to predict the likely response of Whitefish Lake to phosphorus loading changes associated with various lake-management actions that might be implemented, and (6) relate historical lake water quality with precipitation records to assess the effect of climatic factors on lake water quality.
Methodology
Data collection for the development of water and phosphorus budgets for Whitefish Lake will continue through Oct. 31. Instrumentation will be dismantled and piezometers removed. Second-year monitoring data will be compiled and published. Water and phosphorus budgets for the two monitoring years will be constructed and finalized. Phosphorus loading-lake quality response modeling will be completed. The first draft of the study report will be completed.
Publications and Reports
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.
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