Lower Minnesota River - Low Dissolved Oxygen: TMDL Project

This project addresses one impairment in the lower portion of the Minnesota River during low flow conditions. The main sources of excess phosphorus during low flow conditions include wastewater treatment facilities, direct discharges of sewage, stormwater, and agriculture. Results from the TMDL study indicate that, with phosphorus reductions, it is possible to meet the dissolved oxygen standard in the Lower Minnesota River during low flow conditions.

The U.S. Environmental Protection Agency (EPA) approved the Total Maximum Daily Load (TMDL) report in September 2004, and an implementation plan has been developed.

Map and location

The Minnesota River has a dissolved oxygen impairment from river mile 22 to the mouth of the Mississippi River. The Minnesota River is located in the Lower Minnesota River watershed.

PDF icon Map of the impairment within the Lower Minnesota River Watershed

TMDL report and implementation plan


PDF icon 2019 Modification to Lower Minnesota River Dissolved Oxygen TMDL (wq-iw7-02n)

Information contact

Bryan Spindler
Minnesota Pollution Control Agency
12 Civic Center Plaza Ste 2165
Mankato, MN 56001