Upper Cannon Lakes Excess Nutrient Total Maximum Daily Load Study: Jefferson-German Lake Chain

In 2008, the Minnesota Pollution Control Agency (MPCA) listed the Jefferson-German Lake Chain (JGC) as impaired for aquatic recreation due to excess nutrients under section 303(d) of the Clean Water Act. Excessive phosphorus loading is the main cause of the impairment. The goals of the JGC Excess Nutrients Total Maximum Daily Load (TMDL) study are to describe the nature and extent of the lake chain's phosphorus impairment and determine source load allocations that consider major sources. Resources are currently being allocated to the Cannon River watershed (the major watershed that the JGC lies in) to complete a comprehensive assessment, conduct stressor identification focused on biological impairments, construct a watershed model and complete additional TMDLs as necessary. These components of MPCA's watershed approach, particularly the modeling, will allow for simulation of various management scenarios aimed at pollutant load reductions. The focus and primary intent of this project is to better characterize phosphorus levels, probable sources, and estimate reductions required to meet the TMDL water quality goal. Watershed wide phosphorus loading was estimated to assess the magnitude of nonpoint and point sources and establish a cause-effect linkage of loading sources and subsequent in-lake phosphorus concentrations.