Impaired Water - Whitewater Lake (Whitewater Lake)
Walworth County, Wisconsin
Condition has remained stable; water is not impaired.
Whitewater Lake was placed on the impaired waters list for total phosphorus and excess algal growth in 2012. New data indicated good conditions and the water was delisted in 2018. This lake was assessed in each biennial cycle from 2018 and 2022 for phosphorus and algae which showed a healthy system. Aquatic plant communities were evaluated in two separate years, 2014 and 2015, and was in good condition. This lake is on the Healthy Waters List.
Listing Details
Total Phosphorus
Listed For
Current Use
Listing Status
Water Delisted
Attainable Use
Delisted 2018
Designated Use
303(d) ID
Listing Date
Impaired Water Notes
This water was assessed during the 2018 listing cycle; new total phosphorus and chlorophyll sample data were clearly below 2018 WisCALM listing thresholds for the Recreation use and the Fish and Aquatic Life use.

Impaired Water Notes
Whitewater Lake has elevated phosphorus resulting in low dissolved oxygen and algae blooms, likely affecting fish & aquatic life. Although the average TSI based on chlorophyll a (2005-2008) is 59, which places it in the Fair category for a Deep Lowland lake, the average Total Phosphorus concentration (2005-2008) is .035 mg/l, which exceeds the TP impairment threshold of .03 mg/l for Deep Lowland lakes. Summer DO profiles showed less than 5 mg/l at 15 foot depths and below. Per Heidi Bunk, the DO drops more quickly and the thermocline is shallower here than in her other comparable lakes; in her best professional judgment the DO should not be dropping to below 5 mg/l before 18 feet. Heidi has also received frequent phone calls about algae blooms on this lake from the public. Citizen monitors frequently ranked their perception of water quality as 'Enjoyment somewhat impaired due to algae'. During 2008-2009 the lake was devoid of macrophytes. The majority of Whitewater Lake's surface area consists of shallow bays; the deep holes are only about 1/10 of surface area. Recommendations for future monitoring include documentation of algae blooms and blue green algae, chlorophyll a sampling, DO profiles, and additional discussion on the appropriate natural community based on the topography of the lake.

Nonpoint sources are the primary contributors to Whitewater Lake. In 2000 land uses in the watershed were: Agricultural 45%, Woodlands 21%, Urban 15% (10% of which is residential, 0.3% commercial). Part of the lake is within the Southern Unit of the Kettle Morraine, and part has private frontage that is developed.

Impaired Water Notes
This water was assessed during the 2012 listing cycle, and total phosphorus and chlorophyll sample data exceed 2012 WisCALM listing thresholds for the recreation use.