Comments invited on report on restoring lake, streams in Winona area

Contact: Forrest Peterson, 320-441-6972

The Minnesota Pollution Control Agency (MPCA) invites comments on a report on reducing pollutants in Lake Winona and 17 stream sections in the Mississippi River-Winona Watershed in southeastern Minnesota. The report is open for comment through Sept. 24, 2015.

The streams include the Whitewater River and tributaries, many of them popular for trout fishing and other recreation. The river and streams all flow into the Mississippi River in the Winona area. This watershed covers 419,200 acres in Wabasha, Winona and Olmsted counties. The majority of land in the watershed is used for farming.

This report is on a Total Maximum Daily Load (TMDL) study, which determines the maximum amount of pollutants that a water body can accept and still meet standards. This study will help local partners decide on ways to restore Lake Winona and streams. The study incorporated water quality data from the past 10 years, fish surveys, stressor identification investigations, stakeholder input and other information.

The pollutants in this case include phosphorus that causes algal blooms, bacteria that may make water unsafe for swimming, sediment that makes water too cloudy for fish and other aquatic life and nitrate levels that may make water unsafe for drinking.

This area of Minnesota is vulnerable to pollution because of its karst landscape. In karst, only a thin layer of soil covers the porous bedrock underneath and allows pollutants on the land to easily reach groundwater used for drinking. In a karst landscape, where caves and sinkholes are common, streams and groundwater mix as water moves through the bedrock.

To restore Lake Winona to water quality standards, the report calls for a 39 percent reduction in phosphorus for the northwest bay and a 31 percent reduction for the southeast bay.

For the streams to meet standards, the reductions in pollutants depend on the flow conditions because the more flow, the higher the pollutant levels. At mid-flows, reductions of up to 95 percent (Whitewater River, middle fork) are needed for bacteria, up to 6 percent (Whitewater River, south fork) for nitrates, and up to 89 percent (Rollingstone Creek) for sediment.

The fish kill in the Whitewater River in July is not part of this study. While the fish kill is still under investigation, it highlights the need to identify pollution problems and take action to restore water quality.

This study report outlines strategies to reduce pollutants, such as limits on wastewater discharges, urban stormwater controls, feedlot runoff controls, sewer system upgrades and agricultural practices to reduce runoff and erosion. The TMDL study will become part of a more detailed report called a Watershed Restoration and Protection Strategies.

For more information on the study or to submit written comments, contact Shaina Keseley, MPCA project manager (email, phone 507-206-2622). The study is available on the agency's Mississippi River — Winona Watershed webpage.

Comments, which must be in writing, are due by 4:30 p.m. on Sept. 24. The comments must specify which report you are commenting on, include a statement of your interest in the report, and the action you wish the MPCA to take, including specific references to sections of the draft report you believe should be changed and the reasons for making those changes.