Impaired Water - Delavan Lake (Delavan Lake)
Walworth County, Wisconsin
LR01
793600
1,906.03
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
Delavan Lake was evaluated for phosphorus and algae every two years between 2014 and 2022. Chlorophyll-a values were too high as seen in algal blooms on the lake during the summer months.
Listing Details
Pollutant
Total Phosphorus
Listed For
Recreation
Impairments
Excess Algal Growth
Current Use
Restricted Recreation
Listing Status
303d Listed
Attainable Use
Full Body Contact - Swimming, Boating
Priority
Low
Designated Use
Full Body Contact - Swimming, Boating
303(d) ID
2016-213
Listing Date
4/1/2016
Impaired Water Notes
This water was assessed during the 2018 listing cycle; new chlorophyll sample data exceeded 2018 WisCALM listing thresholds for the Recreation use. Total phosphorus data were clearly below Recreation use and Fish and Aquatic Life use listing thresholds.
Date
7/12/2017

Impaired Water Notes
This water was assessed during the 2016 listing cycle; chlorophyll sample data exceed 2016 WisCALM listing thresholds for the Recreation use, however, total phosphorus data do not exceed REC thresholds. Total phosphorus and chlorophyll data do not exceed Fish and Aquatic Life thresholds.
Date
8/7/2015

Impaired Water Notes
This water was assessed during the 2020 listing cycle; new chlorophyll sample data exceeded 2020 WisCALM listing thresholds for the Recreation use. Chlorophyll sample data were clearly below listing thresholds for the Aquatic Life use.
Date
7/24/2019

Impaired Water Notes
This water was assessed during the 2022 listing cycle; new chlorophyll and phosphorus sample data nearly exceeded (May Exceed) 2022 WisCALM listing thresholds for the Recreation use. Chlorophyll sample data were clearly below listing thresholds for the Aquatic Life use. Based on this new data, no listing changes are needed.
Date
4/9/2021