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Wisconsin's Water Quality Report to Congress

Every two years section 305(b) of the Clean Water Act requires states to publish an overall report on the quality of all surface waters across the state. This report, called the "Integrated Report of Water Quality," is submitted to the EPA on April 1 of every even-numbered year.

Wisconsin's 2020 Report to Congress

Wisconsin's Water Quality Report to Congress 2020 was created based on water quality monitoring and restoration work done from 2017 – 2019. The Water Quality Report to Congress, Water Condition Lists, DNR response to public comments, and public comments on the draft Water Condition Lists were all submitted to the EPA on April 1, 2020. Below are copies of these documents:


Figure 1. Percentage of evaluated waters on each Water Condition List, calculated by count.

2020 Water Quality Report Key Points

  • 83% of evaluated waters are healthy (Figure 1).
  • With the approval of the Wisconsin River Basin TMDLs (April 2019) and the Upper Fox & Wolf River Basin TMDLs (February 2020), the number of pollutant listings covered by a TMDL increased by 92%.
  • The number of waters and listings on the Impaired Waters List decreased by about 14%, even accounting for changes in list definition.
  • A total of 139 new pollutant listings were identified in the 2020 update. Of the new listings, 19% are covered by a TMDL restoration plan.
  • A total of 114 listings were removed from the Impaired and Restoration waters lists in the 2020 updates. The majority of removals were for mercury as a result of updated methods of listing.
  • The Water Condition Lists and subcategories better reflect water quality plans in place (Figure 2).
    • Listings covered by Total Maximum Daily Load (TMDL) plans or an EPA approved alternative are placed on the newly created Restoration Waters List, also referred to as the “In-Restoration” list.
    • Nine Key Element Plans are recognized as watershed plans and listings addressed are placed in subcategory 5W.

Figure 2. Changes between listing cycles 2018 and 2020 in number of listings with either a TMDL or Nine Key Plan identified. Orange highlight indicates the Impaired Waters List and gray indicates the Restoration Waters List.

Historical reports to Congress

2018
Wisconsin’s 2018 Water Quality Report to Congress
2018 Water Quality Report Executive Summary

2016
Wisconsin’s 2016 Water Quality Report to Congress
2016 Water Quality Report Executive Summary

2014
Wisconsin’s 2014 Water Quality Report to Congress
2014 Water Quality Report Executive Summary

2012
Wisconsin Water Quality Report to Congress – Year 2012

2010
2010 Wisconsin Water Quality Report to Congress

2008
No Report to Congress

2006
Wisconsin 2006 Water Quality Assessment Report to Congress
2006 Wisconsin Water Quality Report to Congress – Executive Summary

2004
Wisconsin Water Quality Assessment Report to Congress 2004

2002
Wisconsin Water Quality Assessment Report to Congress 2002

Earlier reports are not available in digital format. If you would like to a copy of one of these reports, contact Ashley Beranek.