King Park Stormwater Reuse Project
Projects and Practices 2016: Laws of MN 2015 First Special Session Chapter 2, Article 7, Section 7
The pollutants of concern that are addressed by this project are E. coli bacteria, sediment, temperature (via excess volume) and phosphorus. Quantitative goals include a 77-94% reduction in E. coli bacteria for reach 546 and a 2-62% reduction in E. coli bacteria for reach 545. Qualitative goals include a temperature reduction in reach 545 and 546 to achieve DO standard in reach 545; reduced turbidity in reach, to improve habitat and meet biotic standards. An reduction of sediment loading by 1 ton per year is anticipated, as well as a reduction of 4 lbs/yr of phosphorus.
This project resulted in estimated reductions of 4 lb. of phosphorus per year, 1 ton of sediment per year, 10 acre-feet of stormwater volume per year, and significantly reduced the number of bacteria entering the water resource of concern.
LOCAL LEVERAGED FUNDS
King Park, a city-owned park in Lakeville, consists of baseball fields, a park building, and a parking lot. A portion of Dodd Blvd, a driveway, and the parking lot drain to a stormwater pond at the north end of the park where water is retained, treated, and reused to irrigate two ball fields. This stormwater reuse project was constructed by the Vermillion River Watershed Joint Powers Organization (VRWJPO) and the City of Lakeville in 2010 to meet VRWJPO and city goals. Runoff from the park drains into the Middle Creek tributary (reach 546) and downstream to a confluence with North Creek (545) and the Vermillion River (546). Stormwater contributes sediment, nutrients, bacteria, and heat to reaches impaired for bacteria, dissolved oxygen, fish and macroinvertebrates, degrading these resources. A primary cause of the water quality conditions in this subwatershed, and downstream, is the inability to infiltrate water due to tight soils. Dakota County and City of Lakeville plan to reconstruct part of Dodd Blvd just south of King Park in 2016. The project will provide stormwater treatment to meet regulatory requirements, but due to poor soil conditions, infiltration cannot be achieved. A pump and irrigation system will be installed and will use stormwater from the newly constructed stormwater pond to irrigate two additional ball fields. This system will serve as a surrogate for the much needed infiltration, with plans to expand the system to more ball fields in the future. A reuse system will reduce bacteria, nutrient, and thermal loads to Middle Creek, while providing nutrient benefits for park landscaping. This system would reduce stormwater volume (415,562 cubic feet/year) and thermal load to Middle Creek and downstream reaches; remove sediment (1,416 lbs/year); remove phosphorus (4.3 lbs/year); reduce E. coli (2.4 x 1016 cfu/year) decrease demand on Lakeville's water supply during summer months (3.1 million gallons/year); and maintain landscaping at King Park.