Here Are The Most Polluted Lakes In Minnesota

Minnesota’s 10,000 lakes might look picture-perfect, but some are dealing with more than just a little murkiness these days. From unwanted algae blooms to water that’s not quite swim-ready, a few of these beloved spots have seen better days.

While our fair state is, of course, known for its prestine outdoor lakes, rivers and streams, not all of those waterways have the best water quality. And thanks to the Minnesota Pollution Control Agency (MPCA), we now know the most polluted bodies of water here in the Bold North.

When it comes to lakes, it *is* tough to beat us here in Minnesota, right? And while our famous slogan says there are 10,000 lakes in our state, the Minnesota Department of Natural Resources (DNR) points out that Minnesota is actually home to 11,842 lakes. (I'm not sure why we don't update that slogan; maybe it's because the slogan 'Land of 11,842 Lakes' isn't as catchy.)

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But not all of them are filled with those crystal blue waters we usually associate with heading up north to the lake in Minnesota. In fact, several bodies of water are routinely classified as polluted and land on the MPCA's list of the Most Impaired Waters.

According to the MPCA, a body of water is considered “impaired” if it fails to meet one or more water quality standards. Minnesota water quality standards protect lakes, rivers, streams, and wetlands by defining how much of a pollutant can be in the water before it is no longer drinkable, swimmable, fishable, or useable in other ways.

Following the federal Clean Water Act, the MPCA publishes a list of impaired waters every two years. In its most recent list, out in 2024, it added 199 impairments spanning over 54 water bodies. There are a LOT of lakes, rivers, and streams included on the list (you can check it out HERE). But here are some of the lakes included, thanks to a study by the Metropolitan Council a few years back:

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Meuwissen Lake, west of Chaska,
Chub Lake, south of Lakeville,
Lake Augusta in Mendota Heights,
Lake Maria in Wright County,
Hazeltine Lake in Chaska.

The listing also includes Lake Pepin (which is actually a part of the Mississippi River), thanks to issues with pollution due to high sediment runoff. Lake Phalen in St. Paul is another waterway that's had a history of questionable water quality, thanks to forever chemicals the DNR has been battling.

Luckily though, the DNR says 27 bodies of water and 15 lakes were removed from the list this year. An example is Kohlman Lake in the Ramsey-Washington Metro Watershed District, which improved thanks to over 20 years of restoration efforts and listings for improved water quality.

Meanwhile, if you're looking for some incredible water features that aren't on the MPCA list this year, keep scrolling to check out Minnesota's most incredible waterfalls!