Sustain Our Nation's Forests and Grasslands

Stream water quality monitors find positive indicators of clean water at Midewin

ILLINOIS – August is National Water Quality Month, but on the Midewin National Tallgrass Prairie volunteers monitor stream water quality closely from spring until fall. Volunteers gauge the cleanliness of the stream water on the Midewin by collecting and studying macroinvertebrates. Recent findings have included stoneflies, snail casings and other highly positive indicators of stream health.   

On a recent Tuesday morning, volunteers Cathy Dobbs and Gail Pyndus looked through microscopes at macroinvertebrates that were pulled from Grant Creek. They saw stoneflies and snail casings, which they said are both healthy signs of clean water.

Volunteers Brian Musker and Jenny Cain Vocu collect macroinvertebrates to study stream water quality on the Midewin
Volunteers Brian Musker and Jenny Cain Vocu collect macroinvertebrates to study stream water quality on the Midewin. Photo courtesy of Lynn Dempsey.
Volunteers Cathy Dobbs and Gail Pyndus (at microscope) look closely to identify a stonefly, which is an invertebrate that is an indicator of clean water
Volunteers Cathy Dobbs and Gail Pyndus (at microscope) look closely to identify a stonefly, which is an invertebrate that is an indicator of clean water. USDA Forest Service photo by Veronica Hinke.

“It’s good to see a stonefly,” Pyndus said, “that’s what we want to see more of.”

Other species that indicate clean water are damselflies, dragonflies, mayflies and many more.

Dobbs and Pyndus are a two-person team that gets together twice every month from spring and into the fall. Both juggle their involvement with family and other responsibilities. Dobbs works full-time as a professor at Joliet Junior College while Pyndus is very involved in Plants of Concern monitoring, archaeological explorations and much more on the Midewin.

There are other teams of volunteers that monitor stream water quality at this national forest as well. They pull invertebrates for sampling from nine sites on four streams: four sites at Prairie Creek, two at Jackson Creek, two at Grant Creek and one at Jordan Creek.

Some of the best samples come from rockier areas at the sites, where there tends to be more of a "riffle" action that provides more oxygen.

Since 1996, when Midewin was established by the Illinois Land Conservation Act, the USDA Forest Service and Illinois RiverWatch Network have partnered to conduct stream quality surveys.

The Midewin Volunteer program is managed by The Nature Conservancy in Illinois in a partnership agreement with USDA Forest Service.