Carving a path from polluted to more picturesque in the Minnesota River-Mankato Watershed

Contact: Forrest Peterson, 320-929-1776

Depending on the season and weather, Minneopa Falls southwest of Mankato can be picturesque, chocolate-brown, or even vivid green. In the latter cases, 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 use better land uses to tilt the scene toward improved water quality,” says Wayne Cords, regional watershed manager for the Minnesota Pollution Control Agency (MPCA).

Minneopa Creek and its falls lie within the Minnesota River-Mankato Watershed, where new reports detail causes of water pollution, ways to improve water quality, and how landowners are involved. The reports are available for comment through Sept. 20 and can be viewed here.

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

The Minnesota River-Mankato Watershed drains about 842,000 acres among nine counties through 1,564 miles of streams into the Minnesota River. The Minnesota River valley, carved by a large, prehistoric glacial river, lies hundreds of feet below the upland areas. Elevation through the upland portions of the watershed is relatively flat and well-drained through an extensive network of constructed ditches and subsurface tile. In the transition, active “knick points” with steep stream slopes cut down to the much lower elevation of the Minnesota River.

The Minnesota River-Mankato Watershed is unique, composed of 21 named and many unnamed tributaries and ravines that flow directly into the Minnesota River. Named tributaries vary in size; the largest is the Little Cottonwood River with a drainage area of 167 square miles, and the smallest is Three Mile Creek with a drainage area of 12 square miles.

The tributaries typically have their headwaters near the boundaries of the watershed and flow toward the main-stem Minnesota River. The wetland complex of Swan Lake, the watershed’s largest, lies on the north side of the river. Listed west to east, significant tributaries include: Wabasha Creek, Little Cottonwood River, Morgan Creek, Minneopa Creek, Cherry Creek, Shanaska Creek, Birch Coulee, and Eight Mile Creek. The majority of the streams are considered warm-water. Springs are present, leading to a few coldwater streams including Seven Mile Creek, Spring Creek (Hindeman Creek), and County Ditch 10 (Johns Creek).

Lakes are more prevalent in the eastern portion, including: Washington, Crystal, Loon, Scotch, Wita, Ballantyne, and Henry.

Many of the streams and lakes are in poor condition, often failing to meet water quality standards for aquatic life and recreation such as fish and swimming. Pollutants or conditions contributing to degraded water quality include: Altered hydrology (ditching and tiling), excess nitrogen, excess sediment/solids, excess phosphorus, low dissolved oxygen, degraded habitat, barriers to fish passage, high water temperature, and high levels of bacteria.

“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,” Cord says.

For Minneopa Creek, positive things are happening with its headwater, Crystal Lake. The Crystal Lake Project brings together urban and rural landowners working on watershed improvement projects.

Development of the Minnesota River-Mankato Watershed reports included an organized effort to involve citizens, landowners. Leading local involvement were staff from Soil and Water Conservation Districts and Blue Earth, Brown, Cottonwood, Le Sueur, Nicollet, Redwood and Renville counties. Growing numbers of farmers and landowners see the economic and water quality value of practices such as cover crops, improving soil health, controlling drainage, increasing vegetation, installing or restoring water storage basins, and better management of fertilizer. Many of these practices can also lessen the impact of climate change,

After intensive water monitoring and assessing whether lakes and streams meet water quality standards, the MPCA and local partners have established the following goals in the watershed:

  • 25% reduction in peak and annual river flow.
  • 60% reduction in nitrogen loads.
  • 50% reduction in phosphorus loads.
  • 50% sediment reduction in restoration areas.
  • 60% bacteria reduction.
  • 25% increase in habitat scores.

A long-term commitment is needed to restore and protect the waters of the Minnesota River-Mankato Watershed. Implementing strategies will take 20, 30 years or more with 10-year interim milestones to measure and motivate progress.

Open for comment are the Total Maximum Daily Load (TMDL) study and the Watershed Restoration and Protection Strategies (WRAPS) report. They are companion documents that 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.

These reports are part of a bigger effort to restore waters in the Minnesota River Basin. To learn more, visit the MPCA website. To comment, use the form on the basin web pages or send written comments to Bryan Spindler, MPCA, 12 Civic Center Plaza, Suite 2165, Mankato, MN 56001 by 4:30 p.m. on Friday, Sept. 20.

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.