Redwood River Watershed Monitoring and Assessment Report

Within the Redwood River Watershed, degraded conditions were common, with 74% of the monitored streams failing to meet aquatic life use standards. Poor fish communities contributed to 56% of the aquatic life impaired reaches, while poor macroinvertebrate communities contributed to 49% of the impaired reaches. Both communities contributed to aquatic life impairment on 37% of the reaches. Four reaches had existing aquatic life impairments based on the fish community. Three of these reaches had current data confirming previous impairments, while one reach was not sampled in this survey. There were no previous aquatic life use impairments based on macroinvertebrates. Fish species considered tolerant of pollution often contributed to reaches failing aquatic life use standards. Tolerant fish species are some of the most abundant fish in the watershed, and in many streams, they were the dominant species collected in the sample. The primary issues negatively impacting fish and macroinvertebrate communities within the watershed include excess sediment, lack of habitat, altered hydrology, excess nutrients, and fish barriers.