Watershed-Scale Monitoring of Long-Term Best Management Practice Effectiveness

Minnesota has widespread water quality impairments due to nonpoint-source pollution generated by agricultural, urban, and other human-altered lands. Mitigation of these impairments requires implementing best management practices (BMPs) that are designed to limit soil erosion and nutrient transport from lands to receiving waters. Long-term data sets of water quality and land-use history are needed to tease apart the many factors that affect water quality. In particular, data sets that span periods before and after BMP implementation are needed to determine BMP effectiveness. However, such data sets are lacking because water quality monitoring of our lakes and rivers did not begin until well after humans altered the landscape. To fill this data gap, Researchers at the Science Museum of Minnesota’s St. Croix Watershed Research Station are using this appropriation to construct long-term historical water quality records through analysis of lake sediments in order to enable better determination of the effectiveness of BMPs on improving water quality.