2018 Impaired Waters List

Minnesota’s 2018 Impaired Waters List was submitted to the U.S. EPA for approval on April 4, 2018.

See the Impaired Waters Viewer (IWAV) for all impaired waters, including those just listed, delisted, and corrected for 2018.

File 2018 Proposed Impaired Waters List (wq-iw1-58)
  • Proposed 2018 TMDL (303(d)) List
  • Proposed 2018 Inventory of All Impaired Waters
  • Proposed Appendix A of the Statewide Mercury TMDL (Impairments added to the TMDL)

PDF icon 2018 Guidance Manual for Assessing the Quality of Minnesota Surface Waters for Determination of Impairment 305(b) Report and 303(d) List (wq-iw1-04j)

Describes Minnesota's monitoring and assessment strategy, assessment tools, and the redesigned assessment process. The purpose of this guidance is to define the required data and information and lay out the criteria by which waterbodies are assessed to determine if beneficial uses are supported.

HTML icon Shapefile: Impaired waterbodies 2018 (proposed)

This is a draft set of the impaired waterbodies as determined by MPCA's surface water quality assessment process in 2016 and 2017 for the 2018 reporting cycle to U.S. Environmental Protection Agency (EPA). Waterbodies declared impaired prior to 2018 are also included in this dataset unless they have been delisted. The waterbodies included in the dataset were submitted to EPA in April 2018 as part of the impaired waters list. EPA evaluates the list and either approves it as-is or modifies it, which may result in changes to this spatial data.


Please note: The MPCA has not finalized methods for identifying waters used for production of wild rice or for assessing impairment of waters based on the existing wild rice-related standard. Consequently, the draft 2018 303(d) Impaired Waters List does not include any waters assessed as impaired for the sulfate wild rice standard. The MPCA is in the midst of an effort to revise the sulfate standard to protect wild rice and will develop an assessment approach once that rulemaking is complete.

Public comment

The 2018 list was open for public comment (Nov. 27, 2017, through Jan. 26, 2018).

PDF icon Compilation of all public comments received on the 2018 Draft Impaired Waters List (wq-iw1-58a)

PDF icon Responses to all public comments received on the 2018 Draft Impaired Waters List (wq-iw1-59e)

Other information

PDF icon 2018 Minnesota Water Quality - Narrative report to Congress (wq-s7-51)

Also known as the 305(b) Integrated Report, combines two requirements of the Clean Water Act to report to Congress on the quality of Minnesota's waters.

For GIS professionals: Go to MPCA's spatial data webpage to download shapefiles on Minnesota's impaired waters.