The Delavan Lake - Town Park Best Practices Mgt. Project
The Town Park BMP project was identified in the 2017 Watershed Implementation Plan as a high priority water quality protection project. It is located at the Town Park along the northeastern corner of Delavan Lake at the outlet of the Unnamed Tributary sub-watershed as identified in the Plan. At the Town Park site and immediately upstream, a combination of Best Management Practices (BMPs) were recommended in the Plan that, if completely implemented, were expected to achieve significant nutrient load reductions of phosphorus and sediment. The installed Town Park and Stream Channel BMPs are expected to provide annual nutrient load reductions of approximately 18.1 lbs. of phosphorus and 55 tons of suspended sediment, or annual nutrient load reductions of approximately 20 percent for the Unnamed Tributary Sub-watershed The recommended BMPs within Town Park and upstream of South Shore Drive and Route F South have been installed with the exception of native plantings in Town Park near the lake, which are scheduled to be installed in the Fall of 2020. The BMPs that were installed within Town Park included an energy dissipation area at the road culvert, a cobblestone infiltration channel, a vegetated bio-swale and native wetland plantings adjacent to the lake shore. The BMPs installed in the eroding intermittent stream directly upstream of South Shore Drive included a riprap energy dissipation area directly downstream of the Route F South Culvert, a total of four (4) rock check dams and a riprap revetment to stabilize an eroding stream bank section. Although not included in this project, additional BMPs located upstream (east) of Route F South on land not owned by the Town of Delavan were also recommended in the Plan. They include storm water detention, two grass waterways and other agricultural BMPs. The Town of Delavan plans to pursue this work in the future to further reduce nutrient loadings to the lake and to increase the overall effectiveness of the currently installed Town Park BMPS by trapping additional nutrients and attenuating peak flows during significant storm events..