The Vermillion River Watershed Joint Powers Organization, in partnership with the City of Burnsville, is planning an overall improvement in the Alimagnet Lake subwatershed that consists retrofit two existing stormwater ponds that drain to Alimagnet Lake, a nutrient impaired water, with iron-enhanced sand filter benches. It is estimated that a significant amount of phosphorus reduction will be achieved by implementing this project, bringing Alimagnet Lake closer to state water quality standards.
As part of the Dakota County Transportation Department's highway 78 road reconstruction project, the Vermillion River Watershed Joint Powers Organization is partnering with Dakota County to install a nitrate treatment practice on a tributary to the South Branch Vermillion River adjacent to the road. The South Branch Vermillion River subwatershed is the highest nitrate loading subwatershed in the Vermillion River Watershed and is a significant contributor to contaminated drinking water in the eastern portion of the watershed.
South Creek is a tributary to the Vermillion River and a DNR-designated trout stream. Currently, the creek is not meeting state water quality standards for sediment, temperature and dissolved oxygen The Vermillion River Watershed Joint Powers Organization and the City of Lakeville propose to retrofit an existing stormwater pipe with a hydrodynamic separator to reduce the sediment load reaching South Creek and the Vermillion River. One hydrodynamic separator will be installed and is estimated to reduce sediment loads to South Creek and the Vermillion River by 4 tons per year.
The Vermillion River Watershed JPO is partnering with Dakota County and the City of Lakeville to enhance stormwater management along County Road 50. A treatment train approach with an iron-enhanced sand filter at the tail end to remove dissolved phosphorus will be implemented to treat a drainage area including a portion of the upstream neighborhoods that currently receive little to no stormwater treatment. The practice is anticipated to reduce 20 pounds of phosphorus annually from reaching Lake Marion, a water resource with high recreational value targeted for protection.
South Creek, a tributary to the Vermillion River and a DNR-designated trout stream. Currently, the creek is not meeting state water quality standards for sediment, temperature and dissolved oxygen and it flows through a large stormwater basin in the City of Lakeville. The Vermillion River Watershed Joint Powers Organization, in partnership with the city, propose to create a new channel for the creek in order to separate it from the pond. The result would be significantly cooler temperatures, increased dissolved oxygen, and less sediment-laden water in South Creek.
The Greater Blue Earth River Basin Alliance (GBERBA) along with Soil and Water Conservation Districts, Counties, landowners, and drainage authorities in the ten member counties will install conservation drainage practices to improve water quality. 103E drainage systems with documented sediment or water quality issues are the focus with the goal of installing 52 practices such as improved side inlets (grade stabilization structures), alternative tile inlets, denitrifying bioreactors, saturated buffers, storage wetlands and others.
The purpose of this project is to complete subwatershed analysis for Cannon River and Vermillion River sub-watersheds to prioritize and target Best Management Practices based on cost-effectiveness with regard to pollutant reduction. This process is intended to proactively assist local water management and partner agencies in maximizing the value of each dollar spent to improve water quality in the respective rivers.