Minnesota River Basin Statistical Trend Analysis

The Minnesota River Basin Statistical Trend Analysis summarizes statistical trend modeling results for water quality monitoring sites across the Minnesota River Basin (Basin). Water quality data from 21 stream and river monitoring stations in the Basin were analyzed for trends using two different statistical tests-QWTREND and Seasonal Kendall. The stations are distributed throughout the Basin and vary in scale from the Minnesota River itself to smaller streams such as Chetomba Creek and the Little Cobb River. Four water quality indicators were analyzed-total suspended solids, total phosphorus, orthophosphorus, and nitrate-nitrogen. Most of the data was collected over the past 10 years; although the Minnesota River stations at Mankato and St. Peter have records that go back about 40 years.  Trend analyses were performed on three mainstem, eight major tributary, and nine minor tributary monitoring sites. Results are presented in tables (Appendix B and C) and maps (Appendix D-G).