Marathon County, Wisconsin
CW17
1427400
4,909.17
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
Big Eau Pleine Reservoir was evaluated for phosphorus and algae every two-year cycle between 2012 and 2016 and in the 2022 and 2024 cycles. Phosphorus levels were found to be too high, which was reflected in algal blooms. This lake is part of the Wisconsin River Basin TMDL for phosphorus. According to the Priority Watershed Project Plan (October, 1993), the excessive algae growth is supported by high concentrations of nutrients delivered from the watershed and nutrients are also recycled internally from sediment re-suspension. Pollutant
Mercury
Listed For
Fish and Aquatic Life
Impairments
NA
Current Use
Unsupported Aquatic Life
Listing Status
Pollutant Removed
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Delisted 2008
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
37
Listing Date
4/1/1998
Impaired Water Notes
New data removes Mercury specific advisory. General advisory applies. Still listed for high phoshorus levels and low levels of dissolved oxygen.
Date
4/1/2008
Pollutant
Total Phosphorus
Listed For
Recreation
Impairments
Low DO, Excess Algal Growth, Eutrophication
Current Use
Restricted Recreation
Listing Status
TMDL Approved
Attainable Use
Recreation
Priority
Not Applicable
Designated Use
Recreation
303(d) ID
37
Listing Date
4/1/1998
Impaired Water Notes
WVIC has been collecting winter reservoir dissolved oxygen profiles for the past several years. The data has been submitted to Al Hauber from 1970’s to present. The data shows the reservoir experiences low dissolved oxygen levels during the winter months (below 5 mg/l). This occurs when organic matter and sediment are re-suspended during winter drawdown, which consumes oxygen under the ice. This “zag zone” of low oxygen water then travels downstream. WVIC has installed aerators in attempts to add dissolved oxygen to the zag zone. According to Al Hauber (WCR), there has not been a fish kill since 1990.
According to the Priority Water shed Project Plan (October, 1993), the low winter oxygen levels are a result of oxygen consumption by decaying organic matter that enters the reservoir from tributaries and internally by algae. The excessive algae growth is supported by high concentrations of nutrients delivered from the watershed and nutrients are also recycled internally from sediment re-suspension. The report also indicates fecal coliform bacteria problems occur at the Eau Pleine Park Beach. Fecal Coliform Bacteria counts have exceeded 400 colonies per 100 ml according to the watershed plan.
Date
4/4/2002
Impaired Water Notes
TP and/or chlorophyll data from the period 2006-2010 were insufficient to assess per 2012 WisCALM. However, the previous assessment(s) were carried forward, and the lake remains listed as impaired.
Date
6/13/2011
Impaired Water Notes
This water was assessed during the 2014 listing cycle; total phosphorus and chlorophyll sample data exceed 2014 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use.
Date
1/20/2014
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 is part of the 2019 approved Wisconsin River TMDL addressing Total Phosphorus and Total Suspended Solids.
Date
6/10/2019
Impaired Water Notes
This water was assessed during the 2022 listing cycle; total phosphorus sample data overwhelmingly exceeded 2022 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
5/26/2021