Upper Watershed Volume Reduction

The management of water quality and water levels in the Spring and Prior chain of lakes has been top priority for the Prior Lake-Spring Lake Watershed District (PLSLWD) and local partners. Fluctuating water levels affect recreational use and shoreline stability. Both lakes have poor water quality conditions and are impaired due to excessive nutrients. In 2004, the PLSLWD conducted a study that identified areas draining to Spring Lake that have potential for stormwater storage and infiltration. A recent project narrowed down which opportunities would provide the most cost effective benefits to the downstream lakes. Field data being collected for a wetland functional assessment will be used for identifying and prioritizing sites with high potential for restoration, reestablishment and the capacity to increase storage/ infiltration.
Areas of primary interest for projects include partially and effectively drained wetlands and areas with infiltration potential. Reestablishing natural storage and infiltration will restore hydrologic function to the watershed. Specifically, this project will store an additional 186 ac-ft of stormwater per year in the upper watershed of Spring and Prior Lake through wetland reestablishment and restoring natural infiltration capacity of several low-lying areas.
This project provides additional benefits to Lower Prior Lake, which is currently not listed as impaired. However, monitoring data collected throughout the lake indicate that the lake water quality is borderline impaired according to one key indicator, chlorophyll. Reducing stormwater volume runoff and nutrient loading to Spring and Upper Prior will provide benefits to Lower Prior lake and help prevent this lake from further degradation. Two other lakes found in the upper watershed, Buck and Fish, will also benefit from the stormwater volume reduction project proposed.