Minnesota's impaired waters and TMDLs
Impaired waters viewer (IWAV)
Four views of water resource data are available in the IWAV:
- All impairments: All waters from the 2012 Minnesota impaired waters inventory are shown in this view in red. This is the default.
- Approved TMDLs: Waters with U.S. EPA approved TMDL studies are shown in this view. Waters in the state-wide mercury TMDL are not included in this view.
- Delisted restored: Waters with previous impairments that now meet water quality standards due to corrective actions are shown in this view.
- Delisted new data: Waters with previous impairments that now meet water quality standards based on more comprehensive monitoring data, and not known to be directly due to corrective actions in the watershed, are shown in this view.
- Use the search box below to search for a city or county (example: Dakota County)
- Use the search icon on the menu to search for a stream or lake by name (example: Balsam Lake) or by AUID (example: 15-0016-00)
- An AUID (Assessment Unit Identification) number refers to all or part of a stream, lake, or wetland (example: 15-0016-00)
- For more information about an impaired water body, place the cursor over the water body and click. A pop-up window will open with basic information and underlined links to more details.
- For more information about the MPCA delisting process and a full list of all delisting decisions, go to MPCA's Impaired Waters List webpage.
January 2009 maps of all impaired waters
Download older files from the online archive.
Contact for questions or comments about the shapefiles or the current inventory of impaired waters: Jennifer Crea, 651-757-2294.
- Shapefile: Assessed waters (2012) Map shapefiles which represent the Minnesota 2012 assessments (per Section 305(b) Clean Water Act), including lakes, streams, and wetlands. These files were created for those interested in preparing computerized maps of the 305(b) assessments. To use these files you will need Geographic Information System (GIS) computer software. The zipped file contains shapefiles for use support (aquatic recreation, aquatic life, and aquatic consumption). The projection for the shapefiles is UTM extended zone 15, NAD83. The shapefile was created by the Minnesota Pollution Control Agency using the 1:24,000 scale National Hydrography Dataset.
- Shapefile: TMDL/WRAPS project boundaries This zipped shapefile contains polygons representing the boundaries of Total Maximum Daily Load (TMDL) and Watershed Restoration and Protection Strategy (WRAPS) projects that have been approved by the U.S. Environmental Protection Agency (EPA). This data is intended to be used in water resource management and impaired waters activities. The project polygons were compiled by the MPCA with input from external partners, and the data layer is updated when new TMDL/WRAPS are approved by EPA. The projection for this data layer is UTM Zone 15 North, NAD 1983.