Improving Watonwan River water quality hinges on land use practices that reduce soil, fertilizer loss

Contact: Forrest Peterson, 320-929-1776

Depending on the season and weather, the Watonwan River can be picturesque, or chocolate-brown. In the latter case, geography, rainfall, and land use combine to dislodge tons of sediment, along with fertilizer and algae.

“We can’t change the geography, but we can have better land uses to tilt the scene toward improved water quality,” says Wayne Cords, regional watershed manager for the Minnesota Pollution Control Agency (MPCA).

Learn more about the studies and overall goals for the watershed at an open house on Wednesday, July 31, from 4-7 p.m., at the Sibley Park Pavilion, 900 Park Lane, Mankato.

The Watonwan River rises in central Cottonwood County and flows 113 miles through flat farmland in northern Watonwan and western Blue Earth counties, past the city of Madelia, until it flows into the Blue Earth River about eight miles southwest of Mankato.

Water quality conditions in the Watonwan River Watershed reflect general water quality across southern and western Minnesota: The majority of streams and lakes are not meeting water quality standards for aquatic life and recreation such as fish and swimming. Stormwater runoff and fertilizer loss in drainage tile are the main sources of pollutants in the watershed.

New reports that detail causes of water pollution in the Watonwan River watershed, ways to improve water quality, and how landowners are involved, are available for public review and comment through Sept. 20. Open for comment are the Total Maximum Daily Load (TMDL) study and the Watershed Restoration and Protection Strategies (WRAPS) report.

The report and study quantify pollutant levels, identify pollution sources, propose ways to return water quality to an acceptable level, and describe protection strategies to ensure continued high quality water resources. The documents are available on the MPCA's Watonwan River Watershed webpage.

Much of the river has been straightened and altered to provide for drainage of farmland and for flood reduction. Though the vast majority of the Watonwan watershed is used for farming, mainly corn and soybeans, small lakes and wetlands provide significant habitat for waterfowl.

Watershed restoration depends on substantially higher adoption of land use practices, such as decreased fertilizer use, cover crops, decreased tillage, cropland surface runoff treatment, cropland tile drainage treatment, and improved manure application. A long-term commitment is needed; it could take 20 to 30 years or more with 10-year interim milestones to measure and motivate progress.

“Most of the changes needed to improve and protect water resources are voluntary. Communities and individuals hold the power to restore and protect waters in the Minnesota River-Mankato Watershed. With agriculture the major land use, farming practices that help protect and improve water quality will make the difference,” Cords says. “Some localized areas in the watershed do meet water quality standards, and the land uses that support clean water should be protected.”

These reports are part of a bigger effort to restore waters in the Minnesota River Basin. To learn more, visit the MPCA website at

To provide feedback, use the online comment form or send written comments to Paul Davis, MPCA, 12 Civic Center Plaza, Suite 2165, Mankato, MN 56001. For more information, call him at 507-344-5246.

Written comments must include a statement of your interest in the report (specify which report, WRAPS or TMDL), 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.