Impaired Water - Willow River (Willow River (to confluence of branches))
St. Croix County, Wisconsin
SC03
2606900
26.29 - 32.47
6.18
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
This water was assessed during the 2016 listing cycle; general mIBI assessment indicates that this water is meeting Fish and Aquatic Life use.

Assessments during the 2020 listing cycle show total phosphorus levels too high for healthy aquatic communities like plants, fish, and bugs. Fish sample data were in excellent condition. This water was proposed for the impaired waters list in 2020. This water is covered by a watershed plan: Implementation Plan for the Lake St. Croix Nutrient Total Maximum Daily Load (2025).
Listing Details
Pollutant
Total Phosphorus
Listed For
Fish and Aquatic Life
Impairments
Impairment Unknown
Current Use
Unsupported Aquatic Life
Listing Status
303d Listed
Attainable Use
Default - Fish and Aquatic Life
Priority
Low
Designated Use
Default - Fish and Aquatic Life
303(d) ID
2020-100
Listing Date
4/1/2020
Impaired Water Notes
This water was assessed during the 2020 listing cycle; new total phosphorus sample data exceed 2020 WisCALM listing criteria for the Aquatic Life use, however, available biological data do not indicate impairment (i.e. no fish Index of Biotic Integrity (IBI) scored in the "poor" condition category).
Date
7/29/2019

Impaired Water Notes
This stream is covered by the following watershed plan and this listing was classified as Category 5W as a result: Implementation Plan for the Lake St. Croix Nutrient Total Maximum Daily Load (2025).
Date
8/15/2019