Report: Blue Earth River watershed largely impaired

·4 min read

May 8—By Tim Krohn

MANKATO — A majority of the streams and lakes being monitored in the Blue Earth River Watershed continue to be plagued by sediment, bacteria and nutrients that make them fall short of water quality standards.

The impairments hurt recreation, fish and aquatic insects in the watershed, which is mainly in Blue Earth, Faribault and Martin counties but also reaches into other area counties in southern Minnesota and northern Iowa.

"Down in that part of the state, the issues are pretty persistent," said Dan Olson of the Minnesota Pollution Control Agency, which released new reports based on its latest monitoring of streams and lakes.

The reports found those persistent problems include too much sediment washing into streams, rivers and lakes, which carries fertilizers, bacteria and other nutrients into the water. Those excess nutrients cause algae growth and other pollution problems in the waters.

With nearly 90% of the watershed made up of farmland, MPCA said farming changes offer the best chance to improve water quality.

"The agricultural community, a vital partner in this work, continues to adopt numerous strategies aimed at reducing sediment and nutrient impacts on water resources," the agency said in a press release.

"State and local governments, working together with farm organizations and individual farmers, will be critical to finding and implementing solutions that work for individual farmers and help achieve the goal of clean water."

Studies have shown that the increase in sediment flowing into water comes from more efficient farm field tile drainage systems as well as more frequent heavy rainstorms. The extra water quickly flows off the landscape and into ravines, streams and lakes, eroding stream banks, carrying even more sediment into rivers and streams.

Kevin Paap, a farmer, Blue Earth County commissioner and former president of the Minnesota Farm Bureau, said the ag community is involved in finding solutions.

"As farmers we continue to be at the table and see what we can do to improve water quality."

He is on the board that recently put together the "One Watershed, One Plan" approach to helping improve the Le Sueur River Watershed. The One Plan approach is aimed at various interests in an entire watershed working together with the state on strategies.

"The watersheds don't follow any easy political boundary, so you need to work with a lot of different governments and agencies."

Paap said that he expects a One Watershed, One Plan strategy to be done on the Blue Earth River Watershed in the future.

He said Blue Earth County is unique in its water challenges.

"One thing a lot of people don't realize is there are more miles of rivers in Blue Earth County than in any county in the state. And we have a lot more lakes than people realize."

He said seven watersheds touch into Blue Earth County, and each has its own problems and challenges.

MPCA biologists assessed 77 of 147 stream reaches in the watershed for fish and bugs and the ability to allow for safe swimming. Of the streams assessed, only 19 fully supported aquatic life and none supported aquatic recreation.

The agency also assessed 20 lakes for aquatic life and 24 for aquatic recreation. None fully supported aquatic life and only one supported aquatic recreation.

The MPCA said one strategy to improve water quality is to continue to work with municipalities on their wastewater treatment plants.

"The wastewater sector has made huge improvements in phosphorus reduction over the last two decades, and ammonia concentrations are also largely under control, but nitrate concentrations mostly are not," the MPCA said in the release.

The reports say nitrates can put drinking water sources at risk.

The agency said there are opportunities for more nitrogen management and treatment to reduce nitrates. "For example, the Blue Earth wastewater treatment facility is effectively reducing nitrates in its discharges," the agency stated in the release.

Mankato and Fairmont draw their drinking water from sources at risk for nitrate contamination. The Minnesota Department of Health has developed assessments designed to protect these sources.

But with farming dominating the watershed, the state and county agencies are focusing on largely volunteer efforts by farmers to adopt best management practices in their operations.

Implementing additional best management practices is critical to restoration efforts, the agency said.

County and Soil and Water Conservation Districts from Blue Earth, Freeborn, Faribault, Jackson and Martin counties have developed events throughout the watershed focused on gaining support for increased adoption of soil health practices and other restoration strategies.