Study: Except for bacteria in some creeks, Lake Pepin tributaries are in good shape

Contact: Cathy Rofshus, 507-206-2608

Rochester, Minn. -- While many streams flowing to Lake Pepin in southeastern Minnesota offer high water quality and need protection, a handful of trout streams need reductions in bacteria levels, according to a study by local partners and the Minnesota Pollution Control Agency (MPCA).

The watershed restoration and protection strategy study is open for public review and comment through Sept. 10. A report on the study is available on the MPCA’s http://www.pca.state.mn.us/wfhyde0">Mississippi River – Lake Pepin Watershed webpage. For more information on the study or to submit written comments, contact Justin Watkins, MPCA project manager, at justin.watkins@state.mn.us or 507-206-2621.

The agency and its partners invite the public to an open house about the study on Tuesday, Aug. 26, 4:30-6:30 p.m., at the Frontenac Sportsman Club, 30301 Territorial Road, in Lake City.

The study summarized the health of the watershed. It also included a report on total maximum daily loads, which are the maximum amounts of pollutants that streams can receive and still meet water quality standards.

This study focused on the Mississippi River-Lake Pepin watershed from Red Wing to Lake City. This area encompasses 205,747 acres that drain several small coldwater streams. (This study excluded Lake Pepin, which is the focus of a separate project.) The land is diverse with forests, bluffs and cropland. Many streams here are popular for trout fishing.

For the most part, the streams are in good condition, supporting a healthy community of fish and macroinvertebrates. Macroinvertebrates -- more commonly called “bugs” -- are creatures without backbones, such as insects, snails and clams. By examining a stream’s biological health, scientists can gauge its health. The healthier the water, the more diverse the fish and bug populations.

The study did identify a few concerns. Bacterial levels in Hay, Bullard, Gilbert, Miller and Wells creeks violate the state standard. The bacteria come from manure applied to cropland, rain and snowmelt runoff, and failing sewer systems.

Another concern is the level of nitrogen in some waters. Nitrogen can make water harmful for humans and aquatic life. While none of the trout streams violates the standard of 10 parts per million (ppm) of nitrate, concentrations range from 2-8 ppm. Research in Minnesota and other states has found that human impacts are the main cause of higher nitrogen levels in lakes and streams. In this watershed, manure and fertilizer coming from cropland are likely the main sources of nitrogen. One study of southeastern Minnesota trout streams found that the higher the percentage of row crops in the surrounding watershed, the higher the nitrogen concentrations.

Although nutrient and sediment levels in these streams are low enough for the streams to still meet standards, the pollutants do impact downstream waters, from Lake Pepin all the way to the Gulf of Mexico. Because of that, the study recommends several strategies to protect the streams in southeastern Minnesota and downstream waters.

The study summarizes work in the watershed dating back several years, including intensive water monitoring, sampling fish and bugs at 21 sites, and identifying conditions stressing the health of streams. It recommends:

  • managing fertilizer and manure applications to reduce impacts to waters;
  • expanding cover crops to help keep soil in place and enhance soil health;
  • holding back runoff to prevent flooding and erosion while letting pollutants settle out;
  • improving habitat;
  • restoring streams and their banks;
  • upgrading or replacing sewer systems;
  • complying with the Goodhue County mining ordinance that prohibits the use of certain additives for processing silica sand and requires setbacks from streams and other resources; and
  • continued monitoring to detect changes in pollutant levels and watershed conditions.
  • Local partners played a key role in the watershed study and will play a leading role in protecting the waters. They include Goodhue and Wabasha counties and their soil and water conservation districts, the cities of Red Wing and Lake City, and Wells Creek Watershed Partnership.