Stormwater: Special and impaired waters search

Preparing a Stormwater Pollution Prevention Plan (SWPPP) or applying for a Construction Stormwater permit for a construction project?

Federal regulations require construction activities that disturb a total of one or more acres of soil to be covered under a National Pollutant Discharge Elimination System (NPDES) permit. The MPCA is authorized to operate the NPDES permit program in Minnesota.

The permit will have additional requirements and best management practices (BMP) if your construction project is within 1 mile of and will discharge to:

  • a unique and sensitive water (a "special water")
  • an impaired water

See categories of unique and sensitive waters in Minnesota; refer to Appendix A of the PDF icon Minnesota NPDES/SDS Construction Stormwater General Permit.

Impaired waters are bodies of water that exceed the limits of one or more parameters for surface water quality. There are many types of impairments such as high levels of mercury or too much turbidity. Some impairments have no relationship to construction activity and do not have additional requirements while others do. Impairments that are considered sediment-related include nutrients, turbidity, dissolved oxygen, and biotic impairments. This web-based map tool was designed to assist in identifying these unique waters.