Upper Illinois River Watershed: Illinois River Watershed Partnership Releases Subwatershed Assessment

The Illinois River Watershed Partnership (“IRWP”) issued a document titled:

Subwatershed Assessment for the Upper Illinois River Watershed (“Assessment”)

The IRWP states that the Assessment was undertaken to:

. . . best identify areas of interest (i.e., below average to poor macroinvertebrate diversity) and subsequent best management practice recommendations for the watershed of those areas.

The purpose of the Assessment was stated to be the acquisition of a better ecological understanding of the Upper Illinois River Watershed (“UIRW”).

The IRWP states it received assistance from EAST (Education Accelerated by Service and Technology) programs at area schools. Students were stated to have helped collect stream characteristics and assisted in macroinvertebrate collection, identification, and counting.

Methods utilized in the Assessment included:

• EPA 841-B97-003-Monitoring Water Quality Volunteer Stream Monitoring: A Methods Manual. 4.4.1-Stream Habitat Walk
• EPA 841-B97-003-Monitoring Water Quality Volunteer Stream Monitoring: A Methods Manual. 4.4.2-Streamside Biosurvey-Macroinvertebrates

Areas addressed by the Assessment include:

• Clear Creek (2018 303(d) Impairment for Pathogens)
• Moore’s Creek (2018 303(d) Impairment for Pathogens and Sulfate)
• Lower Muddy Fork (2018 303(d) Impairment for Pathogens and Sulfate)
• Sager Creek (Arkansas Only) (No 2018 303(d) Impairment)
• Goose Creek (No 2018 303(d) Impairment)

A summary review from the Assessment stated:

• 5 out 23 sites assessed had a macroinvertebrate diversity score of poor. Reasonsing could include flow regime, lack of optimal in stream features (i.e., riffles), sampling error, or potentially water pollution.
• 17 out of 23 sites assessed had a macroinvertebrate diversity score of fair with 2 having a divesity score below the subwatershed site average. Recommended BMPs could benefit any stream in the fair category.
• Only 1 site assessed had a macroinvertebrate diversity score of good.

A copy of the Assessment can be downloaded here.