Condition of Minnesota's Lakes, Rivers, and Streams
Minnesota has more than 12,000 lakes and 92,000 miles of rivers within its boundaries. The state’s water abundance gives us our national identity.

However, we know the condition of less than one-fifth of our water bodies. Despite the requirement of the federal 1972 Clean Water Act that states assess the condition of all their waters, only 20 percent of our lakes and about 12 percent of our stream miles have been tested to see if they are clean enough for swimming, safe fish consumption, and to support healthy aquatic life. Of the waters Minnesota has tested, about 40 percent have failed to meet water quality standards established to protect these uses.

The reason for Minnesota’s lack of water quality testing has been a lack of resources. During the past 10 years, the state has spent approximately $1 million annually to assess its lakes and streams, while the annual need actually exceeds $8 million per year. The Minnesota Center for Environmental Advocacy has pushed for increased resources to test all Minnesota’s lakes and rivers for years. 

In 2007 and 2008, the Minnesota Legislature responded, increasing water quality monitoring dollars to over $3 million per year.  Passage of the 2008 Clean Water, Land, and Legacy constitutional amendment should allow sufficient funds to fully assess all of Minnesota’s waters at least once every 10 years, the maximum time period for which assessments remain scientifically valid.

In February 2012, MCEA filed comments on the draft of the 2012 impaired waters list. The draft 2012 list includes 511 new impairments, bringing the total impairments up to 3,638. None of the new impairments were for sulfate – a pollutant that can inhibit the growth of wild rice. MCEA’s comments requested that MPCA consider existing monitoring data for sulfate in waters designated for wild rice growth. Despite data showing high sulfate levels in some areas of the state, MPCA has never listed a water as impaired for sulfate.

Lakes and Rivers Testing Schedule, 2008 - 2018

This map shows the Minnesota Pollution Control Agency’s 10-year work plan for testing Minnesota's lakes and rivers by major watersheds.

Water Quality Testing (Assessment) Results 2010

When water quality is tested in a stream or lake, the water body is listed in one of three categories:

• Meeting the water quality standard (full support). This clean water should be protected through the anti-degredation programs.
• Violating the water quality standards (non-support).These waters are placed on the impaired waters list, which requires the state to develop a cleanup plan called a Total Maximum Daily Load.
• Insufficient information. Some water testing was done, but it wasn’t thorough enough to determine the water’s compliance with water quality standards.  Such waters are technically not assessed.

Waters are tested for one or more of the following: fecal coliform, (or E. coli from animal or human feces), mercury, dissolved oxygen (necessary for fish to survive), ammonia, suspended solids (primarily soil runoff), phosphorus, nitrogen, pH, chlorine, turbidity (cloudiness) and biological communities.

2010 Assessment Maps

The maps below show lake and stream assessment (testing) results for 2010 by pollution type or water quality stressor.  For more information about specific water bodies, see MPCA’s environmental data access page.

Fecal Coliform 

Mercury

Low Dissolved Oxygen, Nutrients 

Ammonia 

Turbidity 

Exceeds eco norms, Phosphorus

PCBs