Impaired Water - Squaw Lake (Squaw Lake)
St. Croix County, Wisconsin
SC08
2499000
109.96
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
This water was originally listed in 2010 due to an impairment of the fish and aquatic life use caused by excess total phosphorus. A TMDL for total phosphorus was approved in 2000.

This water was assessed during the 2012 listing cycle, and total phosphorus sample data exceed 2012 WisCALM listing criteria for the fish and aquatic life and recreation uses. Based on the 2012 assessment, a recreation use impairment (excess algal growth) caused by total phosphorus was added to this listing

This water was assessed during the 2014 listing cycle; total phosphorus sample data overwhelmingly exceed 2014 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use and chlorophyll data exceeded REC and FAL thresholds.

The 2016 assessments showed continued impairment by phosphorus; total phosphorus sample data overwhelmingly exceeded 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use, and chlorophyll data overwhelmingly exceeded FAL thresholds and exceeded REC thresholds. Based on the most updated information, no change in existing impaired waters listing is needed.

This water was assessed during the 2018 listing cycle; new total phosphorus and chlorophyll sample data exceeded 2018 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use. New data in 2020 confirm listing.
Listing Details
Pollutant
Total Phosphorus
Listed For
Recreation
Impairments
Eutrophication, Excess Algal Growth
Current Use
Restricted Recreation
Listing Status
TMDL Approved
Attainable Use
Full Body Contact - Swimming, Boating
Priority
Not Applicable
Designated Use
Full Body Contact - Swimming, Boating
303(d) ID
462
Listing Date
4/1/1998
Impaired Water Notes
This water was assessed during the 2018 listing cycle; new total phosphorus and chlorophyll sample data exceeded 2018 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use.
Date
7/10/2017

Impaired Water Notes
A TMDL was approved by the EPA August 24, 2000 for Squaw Lake, located in the Star Prairie Township, St. Croix County, Wisconsin, in the St. Croix River Basin. Squaw Lake is listed on the Wisconsin Department of Natural Resources’ (WDNR) 1998 303(d) List of Impaired Waters. The Lake is nutrient (phosphorus (P)) impaired as a result of agriculture, internal loading and local land use, is listed as a medium priority water and external load sources are nonpoint source (NPS) dominated. The designated use for Squaw Lake is defined as a full recreation, warm water sport fishery water.

Water quality in Squaw Lake is generally poor to very poor, falling in the eutrophic to hypereutrophic category. Summer lake phosphorus levels are about 270 ug/l. Mats of filamentous algae cover a large portion of the lake bottom and summer algal blooms result in foul odors and an unsightly build-up of algae biomass on the shoreline. In addition, trophic conditions in the lake limit rooting depth for emergent vegetation used by the resident fish populations. As a result, these impairments impact the recreational/aesthetic value of the lake and stress sport fish populations.
Date
8/22/2000

Impaired Water Notes
This water was assessed during the 2012 listing cycle, and total phosphorus and chlorophyll sample data exceed 2012 WisCALM listing criteria for the fish and aquatic life and recreation uses. Based on the 2012 assessment, a recreation use impairment (excess algal growth) caused by total phosphorus was added to this listing.
Date
6/15/2011

Impaired Water Notes
FAL use impairment was chaned from "excess algal growth" to "eutrophication" per 2012 WisCALM.
Date
8/25/2011

Impaired Water Notes
This water was assessed during the 2014 listing cycle; total phosphorus sample data overwhelmingly exceed 2014 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use and chlorophyll data exceeded REC and FAL thresholds.
Date
3/24/2014

Impaired Water Notes
This water was assessed during the 2016 listing cycle; total phosphorus sample data overwhelmingly exceeded 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use, and chlorophyll data overwhelmingly exceeded FAL thresholds and exceeded REC thresholds.
Date
10/9/2015

Impaired Water Notes
This water was assessed during the 2020 listing cycle; total phosphorus sample data overwhelmingly exceeded 2020 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use, and chlorophyll data also exceeded REC and FAL thresholds. Based on the most updated information, no change in existing impaired waters listing is needed.
Date
6/19/2019