Lake Margaret Nutrient TMDL

This Total Maximum Daily Load (TMDL) study addresses a nutrient impairment in Lake Margaret (11-0222). The goal of this TMDL is to quantify the pollutant reductions needed to meet State water quality standards for nutrients. Lake Margaret is located in the City of Lake Shore, Cass County, Minnesota, in the Upper Mississippi River watershed. It is a highly used recreational water body with an active fishery and provides other aesthetic values as well. The drainage area to the lake is 45,206 acres of land that is predominantly timber followed by small percentages of agriculture, pasture, and wetlands. The drainage area contains portions of the City of Lake Shore in the southeast corner but is mainly comprised of rural county areas including Moose Lake, Maple, Loon Lake, Meadow Brook, Home Brook, May and Fairview townships. The outlet to Lake Margaret is a channel at the north end of the lake where it flows into Upper Gull Lake, which is part of the Gull Lake Chain of Lakes. Water quality is considered fair with the lake still viewed as a popular destination for recreational activities. Wasteload and Load Allocations to meet State standards indicate that average nutrient load reductions of 44% would be required to consistently meet standards under average precipitation conditions. Internal load management and reduction of phosphorus from watershed runoff by controlling sources from pastures and developed land (impervious surfaces) would have the most impact on reducing phosphorus load and improving water quality in Lake Margaret