Comments invited on strategies for restoring waters in Le Sueur River area

Contact: Cathy Rofshus, 507-206-2608

Mankato, Minn. — The Minnesota Pollution Control Agency (MPCA) invites comments on two reports outlining strategies to restore the Le Sueur River and other waters in its drainage area, also called a watershed. The reports are open for comment through April 29.

This watershed is one of the most polluted watersheds in Minnesota, according to data collected statewide. Impairments — waters that fail to meet standards — are common throughout the watershed.

The Le Sueur watershed covers 711,000 acres in south-central Minnesota. It drains parts of Blue Earth, Faribault, Freeborn, Steele and Waseca counties. This river meets the Blue Earth River near Mankato, where drinking water wells extract water from below the Blue Earth River.

The MPCA and local partners have intensely monitored waters in the Le Sueur drainage area and assessed them to see if they meet state water quality standards. They have also identified conditions that stress fish and other aquatic life, as well as conditions that support this life and other benefits. The agency has drafted Watershed Restoration and Protection Strategies for the Le Sueur area as a whole.

It has also drafted Total Maximum Daily Loads (TMDLs), which are the maximum amounts of pollutants that water bodies can accept and still meet standards, for six sections of streams and four lakes:

  • Little Cobb River, from Bull Run Creek to the Cobb River, for low dissolved oxygen related to nutrient levels. Reductions in phosphorus from nonpoint sources such as field runoff and from point sources such as wastewater are needed to meet standards.
  • Parts of the Le Sueur River, Boot Creek, Rice Creek, County Ditch 3 and Cobb River for bacteria levels. Reductions of 19 to 70 percent are needed to meet standards.
  • Madison, Elysian, Eagle and Freeborn lakes for nutrient levels. Reductions of 61.8 to 73.5 percent are needed to meet standards.

Major stressors in this watershed include these interrelated factors:

  • Changes to the watershed’s hydrology.
  • Lack of habitat.
  • High nutrient levels. Nutrients can lead to algal blooms that can harm aquatic life such as fish and recreation such as swimming.
  • High turbidity levels. Turbidity is a measurement of how cloudy or muddy water is, with standards set for clearer water to support aquatic life and recreation.

These stresses result from the significant changes during the past 150 years. Since European settlement in the 1860s, the watershed has undergone major land changes, including the plowing of its native prairies, harvesting of its hardwood forests, draining of its wetlands and modifications to its natural stream courses. Agriculture accounts for the majority of land use activities within the watershed. Farmland is highly tiled for drainage purposes. Climate change is worsening the impact of these changes.

The Le Sueur River’s flow has roughly doubled during the past 60 years, some of it attributable to increased precipitation but much of the higher flow is due to tiling and crop changes, according to several studies. This higher flow has led to higher erosion of bluffs, streambanks and ravines, resulting in high levels of sediment in the river.

A main strategy to restoring waters in this area is mitigating the changes in hydrology through conservation tillage, water retention basins, restored wetlands, controlled drainage and other methods. Other strategies include buffers along waterways, streambank stabilization, septic system upgrades and stormwater management.

The reports are available online by going to www.pca.state.mn.us and searching for “Le Sueur watershed.” Comments on the reports are due by 4:30 p.m. on April 29, to Paul Davis, MPCA project manager, at paul.a.davis@state.mn.us or 12 Civic Center Dr., Ste. 2165, Mankato, Minn. Davis can be reached by at 507-344-5246 or 1-800-657-3864.

Written comments must include a statement of your interest in the report; a statement of the action you wish the MPCA to take, including specific references to sections of the draft report you believe should be changed; and specific reasons for your position.