Wild Rice River Watershed Stressor Identification Report

The Minnesota Pollution Control Agency (MPCA) follows a watershed approach to systematically monitor and assess surface water quality in each of the state's 80 major watersheds. A key component of this approach is Intensive Watershed Monitoring (IWM), which includes biological (i.e., fish and macroinvertebrate) monitoring to evaluate overall stream health. In 2014 and 2015, the MPCA conducted biological monitoring at several stations throughout the Wild Rice River Watershed (WRRW). An Index of Biological Integrity (IBI) score was then calculated for each fish (F-IBI) and macroinvertebrate (M-IBI) monitoring visit. The biological monitoring results for the watershed were assessed to identify individual stream reaches that were not supporting a healthy fish and/or macroinvertebrate assemblage. A reach with a low IBI score(s) (i.e., below an established threshold) is considered "impaired" (i.e., unable to support its designated beneficial use) for aquatic life. A total of seven reaches were determined to have a F-IBI and/or M-IBI impairment in the WRRW, including segments of Felton Creek/County Ditch 45, Garden Slough, Mashaug Creek, South Branch of the Wild Rice River, Spring Creek, and the Wild Rice River.