Lake St. Croix - Excess Nutrients: TMDL project

Lake St. Croix, the lower 25 miles of the St. Croix Basin between Stillwater, Minn., and Prescott, Wis., was designated as an impaired water in 2008 for excess phosphorus. The St. Croix River's headwaters are at St. Croix Lake near Solon Springs, Wis., where it flows west and south over 160 miles until it joins the Mississippi River at Prescott. Approximately 80% (129 miles) of the St. Croix River forms part of the boundary between Wisconsin and Minnesota. The TMDL will be jointly developed by the Wisconsin Department of Natural Resources (WDNR) and the Minnesota Pollution Control Agency (MPCA) with support from the St. Croix River Water Resources Planning Team; an interagency planning team consisting of federal, state and local members formed to work together to protect and enhance the water resources in the St. Croix River Basin.

Map and location

Lake St Croix is located in the Lower St. Croix River watershed and the Mississippi River - Lake Pepin watershed.

PDF icon Map: Upper Mississippi River Basin - Twin Cities Metropolitan Area

More maps are available using the MPCA's Impaired Waters Viewer.

Sources of phosphorus

TMDL report and implementation plan

Other documents


Information contact

Eric Alms
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, MN 55155