1.0 Introduction and Summary
The Six Mile Marsh subwatershed is located along the southwestern boundary of the Minnehaha Creek Watershed District (MCWD or District) and within the cities of St. Bonifacius and Victoria and in Laketown Township and Watertown Township. The subwatershed is the most rural and undeveloped in the District, with agriculture the most common land use. The Three Rivers Park District’s Carver Park Reserve in the central subwatershed contains rolling, wooded terrain, lakes, and wetlands, and is home to a wide variety of wildlife.
The subwatershed contains several major lakes, including Pierson, Wasserman, East and West Auburn, Steiger, Zumbra-Sunny, Stone, Lunsten, and Parley Lakes. Six Mile Creek is formed at the outlet of Pierson Lake and flows 12 miles to Halsted’s Bay on Lake Minnetonka. The creek is mainly comprised of ditches running through large wetland and marsh areas connecting several of these lakes.
Two of the lakes in the subwatershed are listed on the State’s 303(d) list of Impaired Waters for excess nutrients, and Total Maximum Daily Load (TMDL) studies are being developed to plan for their improvement. Other lakes in the subwatershed either meet their water quality goals or strategies for their improvement have been developed in this plan. Many of these lakes are popular fisheries, and water quality improvement will assist in preserving their integrity. Six Mile Creek conveys significant phosphorus and sediment loads to Halsted’s Bay, and is a major cause of its poor water quality. The water quality in Six Mile Creek, its low gradient and the large number of wetlands through which it flows limit the biotic integrity of the creek. Numerous high-value wetlands are present in the subwatershed.
Over the next ten years, the District’s focus in the Six Mile Marsh subwatershed includes sustaining and improving ecological integrity of the subwatershed as it develops. The following will be particular focus areas:
- Conserving ecological integrity through Land Conservation Program activities in key conservation areas.
- Minimizing impacts on water resources from future development through enhanced regulation that requires higher levels of pollutant removal and increased infiltration of runoff.
- Improving water quality in the lakes through regulation and treatment of runoff as well as through implementation of capital improvement projects.