Medicine Lake - Excessive Nutrients: TMDL project

Local resident enjoying a sunset on Medicine Lake Medicine Lake and most of its watershed are located within the city limits of Plymouth and is surrounded by a mix of private lakeshore lots and parkland. The lake has a surface area of 902 acres, a maximum depth of 49 feet, and an estimated mean depth of 17.5 feet. In addition to Plymouth, the city of Medicine Lake and portions of Golden Valley, New Hope, and Minnetonka constitute the remaining watershed area. The Medicine Lake watershed is essentially fully developed and has a total area of 11,613 acres (including lake surface area). Runoff from the watershed enters the lake from creeks, storm sewer outfalls, and culverts at various points along the lakeshore. Stormwater from approximately 86% of the Medicine Lake watershed currently drains through some form of wet detention before it enters Medicine Lake.

In 2004, Medicine Lake was placed on the MPCA’s impaired waters list as the available data indicated that Medicine Lake exceeded the state’s narrative criteria for nutrients (based on total phosphorus, chlorophyll-a and Secchi disc transparency) for the growing season mean. Similarly, Medicine Lake has typically not met the BCWMC water quality goals. Medicine Lake will continue to be affected by the problems that occur when a lake’s watershed has become urbanized. The increased volume and pollutant levels of stormwater runoff from the watershed, combined with internal sources of phosphorus, result in periods of poor lake water quality. A reduction in the phosphorus concentration in the lake is necessary to improve or maintain water transparency and reduce algal blooms. The MPCA is partnering with Bassett Creek Watershed Management Commission (BCWMC) and Three Rivers Park District (TRPD) to develop the work products necessary to complete a TMDL and implementation plan for Medicine Lake.

Map and location

Medicine Lake is located in Hennepin County, in the Mississippi River - Twin Cities watershed in the Upper Mississippi River basin.

TMDL report and implementation plan

Other documents

Project work products

Previous reports/plans for Medicine Lake

Meetings and events


Contact MPCA about this project