Moody Lake Capstone Projects

Moody Lake is a major lake within the headwaters of the Comfort Lake-Forest Lake Watershed District northern flow network, and as such, its water quality sets the stage for downstream waters, particularly Bone Lake, Comfort Lake, the Sunrise River, and ultimately Lake St. Croix. A multi-year diagnostic and implementation feasibility study was conducted in the Moody Lake watershed to prioritize nutrient sources, target cost-effective BMPs, and estimate the measurable phosphorus reductions that will be achieved through implementation of these projects. The District received a FY16 CWF grant to rehabilitate phosphorus-laden wetlands in the northwest portion of the watershed, achieving 80% of the watershed phosphorus load reductions needed for Moody Lake to meet water quality standards. The District received a FY18 CWF grant to perform a whole-lake alum treatment on Moody Lake, bringing the 2020 in-lake summer phosphorus concentration to 37 ?g/L. Combined, these projects achieved a phosphorus reduction of 779 lb/yr, or 90% of the total phosphorus load reduction goal of 879 lb/yr. The District proposes to achieve the remaining 100 lb/yr (10%) external load reduction through implementation of the ongoing FY19 Bone/Moody Subwatershed Assessment Implementation grant project and the proposed FY22 grant projects.

The District will target projects to achieve the remaining phosphorus load reduction to Moody Lake. CLFLWD performed diagnostic monitoring and site-specific wetland coring to target remaining phosphorus loading hotspots in the direct drainage area. Potential projects include: wetland phosphorus-laden sediment excavation, raingarden and/or shoreline restoration, implementation of wetland treatment cells, and agricultural best management practices. Cumulative phosphorus reduction under the proposed projects is estimated at 45 lb/yr.