Location: White Bear Lake, Minnesota
Client: Rice Creek Watershed District
The Rice Creek Watershed District (RCWD) has been working to improve the water quality throughout the District, including those waters that are directed to Bald Eagle Lake. The RCWD proposed constructing a wet pond and iron enhanced sand filter (IESF) along Ramsey County Ditch (RCD) 11 to achieve this goal.
The project site is located between Bald Eagle Lake and White Bear Lake on two undeveloped lots. This area provides minimal treatment for stormwater runoff that enters the RCD 11 public drainage system, which eventually discharges into Bald Eagle Lake. The RCWD retained Houston Engineering, Inc. (HEI) to first complete the feasibility study for the proposed wet pond and IESF.
After being awarded a Clean Water Fund Grant through the Board of Water and Soil Resources to construct the project, the RCWD contracted HEI to proceed with plan development and construction administration. The design reduces the concentration of phosphorus by settling larger particulates in the wet pond, and filtering out fine sediment and dissolved phosphorus by pumping the ponded water through an IESF system.
One early challenge to the design of the project was the variability of flows in RCD 11. The design needed to accommodate high discharge, short-duration flows from the local neighborhood, as well as moderate flow, long-duration flows from White Bear Lake. The design also needed to consider long-term maintenance for both the pumping system and pond dredging.
Tight site constraints required a well-planned layout and grading of access routes for this maintenance. The construction of the project was completed during the summer of 2020. The project provides a sustainable water management solution that is both functional and educational.
Learn more about pump-and-treat IESFs in this article.
- Pumping system components were matched to existing RCWD infrastructure enabling easier maintenance and improved compatibility.
- Project design provides a comprehensive solution that targets coarse and fine sediment along with dissolved phosphorus.