Minnesota's Impaired Waters and TMDLs

TMDL Project: Schmidt, Pomerleau, and Bass Lakes TMDL — Excess Nutrients

Background

Schmidt Lake


Bass Lake
photo credit: Sally and Jim Strand

Almost the entire drainage area of Schmidt, Pomerleau, and Bass Lakes is located within the city of Plymouth in the northwestern suburban Twin Cities metropolitan area, with a fraction located in the city of Maple Grove. The Pomerleau Lake and Schmidt Lake subwatersheds drain through the Bass Lake subwatershed to Bass Lake. Bass Lake outlets through Bass Creek to Shingle Creek, which outlets into the Mississippi River.

Bass Lake is approximately 175 acres in size, averages 10.1 feet in depth, and 82% of the surface area is littoral (i.e. less than 15 feet in depth). Pomerleau Lake is approximately 30 acres in size, averages 10.9 feet in depth, and 66% of the surface area is littoral. Schmidt Lake is approximately 37 acres in size, averages 5.5 feet in depth, and 92% of the surface area is littoral. There are about 7 storm sewer outfalls discharging into Bass Lake as well as Bass Creek and 8 storm sewer outfalls to Schmidt Lake.

Schmidt, Pomerleau, and Bass Lakes were placed on the 2002 impaired waters list for aquatic recreation because the lakes exceed the water quality standard for nutrients. Excess nutrients such as phosphorus from stormwater runoff create poor water quality conditions causing frequent summer algal blooms, which limit recreational activities.

The goal of this TMDL is to quantify the pollutant reductions needed for Schmidt, Pomerleau and Bass Lakes to meet state water quality standards. The MPCA is partnering with the Shingle Creek Watershed Management Commission and their consultant, Wenck Associates, Inc. to complete both the TMDL report and implementation plan for these lakes.

Map and location

Schmidt, Pomerleau, and Bass Lakes are located in the city of Plymouth in northwestern Twin Cities metro area, Hennepin County. The lakes lie in the Mississippi River - Twin Cities watershed of the Upper Mississippi River basin

Maps:

• Map of Schmidt, Pomerleau, and Bass Lakesheds
• 2008 Map of Impaired Lakes in the Twin Cities Metropolitan Area
• More maps are available using the MPCA's Impaired Waters Viewer.

TMDL report and implementation plan

• Fact sheet
• Final TMDL
• EPA Approval Letter (September 25, 2009)
• TMDL Implementation Plan (Approved by MPCA on December 3, 2009)

Other documents

None.

Meetings and events

See the TMDL Meetings, Events and News page for notices of general interest and event-related information on impaired waters/TMDLs.

Links

• Local Sponsor: Shingle Creek Watershed Management Commission
  • Consultant: Wenck Associates
• MPCA: Upper Mississippi River Basin
• MPCA: Minnesota’s Impaired Waters and TMDLs

Information contact

Barb Peichel
TMDL Project Manager
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, MN 55155
651-757-2646
barbara.peichel@pca.state.mn.us