Monitoring the Long-Term Effectiveness of Metropolitan Cold Weather BMPs, Long-term Assessment of Phosphorous Free Fertilizers and Golf Course BMP

Six small residential sub-watersheds were monitored from 2001 to 2006 to characterize residential runoff and track changes in phosphorus concentration and export associated with the use of phosphorus free fertilizer. The study design utilized a paired-watershed approach where three of the sub-watersheds were located in the city of Plymouth, Minnesota where the use of lawn fertilizer containing phosphorus was restricted in 1999, (treatment watersheds); the remaining three sub-watersheds were located in Maple Grove, Minnesota where phosphorus fertilizer restrictions were not initiated until 2004, (control watersheds). These sub-watersheds were carefully selected to include one newly developed area less than 5-years old, (P1 and MG1), one development between 5 and 15-years old (P2 and MG2), and one neighborhood older than 15-years, (P3 and MG3), within each of the municipalities, (Figures 1 and 2). The sub-watershed areas were located within 10 kilometers of each other to minimize differences in precipitation patterns, soil types, and aerial phosphorus loading.