The South Fork Rush Creek Subwatershed Assessment (SWA) evaluates conditions in that part of the Elm Creek watershed that drains to the South Fork Rush Creek. The South Fork and its tributary County Ditch #16 have impaired fish and macroinvertebrate biotic communities which are stressed by excessive nutrient concentrations in streamflow. High concentrations of E. coli and chloride in the South Fork further stress aquatic organisms. Jubert Lake in the study area is not formally listed as Impaired but has high levels of nutrients in the summer.
The 23.4 square mile Study Area is primarily in the City of Corcoran, Minnesota, with a sizable percent in the City of Maple Grove, and a small area within the City of Medina. The SWA used several modeling tools to estimate stormwater runoff and pollutant loading to the streams. Other data such as feedlot and other animal locations, potential septic system locations, and stream conditions, was also collected and analyzed.
The end result was an identification of the most feasible and cost-effective best management practices (BMPs) to address the several impairments in this Study Area. These were prioritized based on several factors including buildability. Cost estimates and pollutant load reductions were estimated for the most technically feasible. Areas where outreach to property owners about additional practices they could consider were also identified.
This subwatershed is one of three where the Commission and Hennepin County have partnered to make a significant amount of funding available to property owners willing to take on voluntary practices such as manure management, water control structures, exclusionary fencing, and grassed waterways on their properties.