In 2017, Dakota County completed a lake water quality assessment of the Lebanon Hills Regional Park chain of lakes system to study the increasing levels of phosphorous, a nutrient that supports plant growth.
When too much phosphorous gets into our lakes, it causes problems such as algae growth, low levels of oxygen for aquatic life, and murky water which makes it difficult for aquatic plants to grow.
Dakota County identified significant upstream sources of phosphorus to Jensen Lake, the headwaters of the main Lebanon Hills Chain of Lakes system, and to Schulze Lake which resides in a smaller sub-watershed that includes Portage Lake. The study found a significant amount of phosphorus in the runoff water following storm events which can be treated by an iron-enhanced sand filter.
In 2018, Dakota County applied for and was awarded a Clean Water Fund Projects and Practices grant from the Minnesota Board of Water and Soil Resources with additional support from Dakota County to install two iron-enhanced sand filters to treat runoff into the chain of lakes.
The first filter will be placed on the south side of Jensen Lake and will benefit Jensen, Sedge, and Beaver ponds; O'Brien Lake; Cattail Lake; and McDonough Lake. The second filter will be placed south of Portage Lake and will benefit both Portage and Schulze lakes.
The projects are expected to significantly protect and improve the health of the Lebanon Hills chain of lakes, with 30 percent progress toward Schulze Lake's water quality goal. The remaining 70 percent of the Schulze Lake water quality goal is being addressed through the Alum Treatment project.
March–June 2020: Develop preliminary plans
June–July 2020: Finalize plans and release project for construction bids
Late 2020: Complete construction of the Jensen and Schulze Lake iron-enhanced sand filters
Please contact Mike Behan, Stormwater Environmental Specialist at 952-891-7539 or email@example.com with any questions.