Lake Rebecca Water Quality Improvement Project
Three Rivers Park District
This project improved the water quality of Lake Rebecca in Lake Rebecca Park Reserve, and improved the fish habitat in the premier muskellunge brood stock lake in Minnesota. Water quality improvements were achieved through a combination of implementing manure management activities in the watershed to reduce phosphorus inflow to Lake Rebecca, control of the invasive species curly-leaf pondweed, and application of alum (aluminum sulfate) to reduce internal phosphorus loading. The in-lake phosphorus concentration, as of June 2011 was reduced to less than 40 ppb and the lake water clarity was improved to over three meters Secchi disk visibility. Visibility for game fish such as muskellunge, is significantly improved. Fewer than 70 acres of Curly-leaf pondweed were present in the lake in spring 2011 after three years of treatment. The habitat availability resulting form the decrease in the exotic curly-leaf pondweed population is being utilized by native aquatic macrophytes which are increasing in distribution and density.