Watonwan River Watershed Stressor Identification Report

Over the past few years, the Minnesota Pollution Control Agency (MPCA) has substantially increased the
use of biological monitoring and assessment as a means to determine and report the condition of the
state’s rivers and streams. This basic approach is to examine fish and aquatic macroinvertebrate
communities and related habitat conditions at multiple sites throughout a major watershed. From these
data, an Index of Biological Integrity (IBI) score can be developed, which provides a measure of overall
community health. If biological impairments are found, stressors to the aquatic community must be
identified. This report summarizes stressor identification work in the Watonwan River Watershed. There were
30 reaches identified with biological impairment in the Watonwan River Watershed. The impairments in
this report are organized by 10-digit Hydrologic Unit Code (HUC). There are six HUCs discussed in this
report.