305b Assessments of Stream Conditions in Minnesota's Major River Basins
Stream assessments are prepared for the U.S. Congress under Section 305b of the Clean Water Act to:
- estimate the extent to which Minnesota waterbodies meet the goals of the Clean Water Act and attain state water quality standards, and
- share this information with planners, citizens and other partners in basin planning and watershed management activities.
These assessments are a fundamental part of MPCA's state water quality management program.
A major shift in 305b assessments in Minnesota occurred for the 2004 assessment reporting cycle. The USEPA had requested States integrate their reporting for sections 303d and 305b of the Clean Water Act and Minnesota has sought to comply by preparing an integrated assessment report since 2004. In order to accomplish this all streams in the state for which data were available were assessed instead of making assessments on a rotating basin cycle as was done in previous assessments.
Two major goals of the Clean Water Act: 1) fishable waters, and 2) swimmable waters, are assessed here in terms of three types of use supports, Aquatic Life, Aquatic Consumption, and Aquatic Recreation, with each use assessed as either:
- fully supporting (FS)
- not supporting (NS)
- insufficient information (IF)
- not assessed (NA)
To view stream assessments, select the major river basin from the map or list files shown below. The stream reaches are grouped by major watershed. The stream assessments include a column containing a category, which reflects the overall categorization an assessment unit receives in the integrated assessment process based on the assessments of individual use supports. For a complete description of the categorization process and for the determination of impairment, please read the 
Guidance Manual for Assessing the Quality of Minnesota Surface Waters (note pages 98 through 101). More information is available on the Total Maximum Daily Load (TMDL) Web page.
Basins in Minnesota
Basin Reports
- 2010 Integrated Report: Surface Water Section (Abbreviated Narrative Report) (wq-s7-50) - Report to the Congress of the United States: Water Years 2008-2009. This report integrates 305b assessments, which measure attainment of standards for fishable and swimmable waters, and 303d (TMDL) listings of impaired waters. Assessments are organized by basin for the entire state and the report also presents statewide summaries. The report describes Minnesota's monitoring and assessment strategy, assessment tools, and the integrated assessment process. It also briefly describes the state's response to these assessments in terms of development and implementation of TMDLs and special state strategies.
Stream Assessments
Please note that the interative maps below will open in a new browser window. For the interactive maps to work best, your computer should:
- Be using Internet Explorer 5.0 or later.
- Have the screen resolution set at 1024 by 768 pixels.
- Have pop-up blockers turned off.
Map Shapefiles
The zipped (compressed) file below contains shapefiles which represent the Minnesota 2010 stream assessments (per Section 305(b) Clean Water Act). These files were created for those interested in preparing computerized maps of the 305(b) stream assessments. To use these files you will need Geographic Information System (GIS) computer software. The zipped file contains shapefiles and metadata for aquatic consumption, aquatic life and aquatic recreation use supports for streams. The projection for these shapefiles is UTM extended zone 15, NAD83. The shapefiles were created by the Minnesota Pollution Control Agency using the 1:24,000 scale National Hydrography Dataset. If you have any questions or comments, please contact Jen Crea at 651-757-2294.
Map Shapefile of Minnesota 2010 Stream Assessments (Zip file size = 12 MB)
More Information
For more information about the 305b assessments of stream water quality in Minnesota's major river basins, contact Elizabeth Brinsmade at the Minnesota Pollution Control Agency, at 651-757-2244.
