StreamWatch report reveals decade-long poor water quality in Rivanna River watershed

A recent report by local water monitoring group StreamWatch reveals that nearly 70 percent of area streams fail to meet state standards. Photo courtesy StreamWatch A recent report by local water monitoring group StreamWatch reveals that nearly 70 percent of area streams fail to meet state standards. Photo courtesy StreamWatch

After a decade of assessments by its volunteers, local watershed monitoring group StreamWatch has reported that 70 percent of streams that drain to the Rivanna River are failing state water quality standards. It’s far from an ideal finding, but as the citizen science organization points out, the situation could be worse.

In a report released earlier this month, StreamWatch revealed that 31 of the 45 streams tested in the Rivanna watershed have not improved in the 10 years the group’s been testing the waters.

StreamWatch uses a technique called benthic macroinvertebrate sampling, which means volunteers splash into the streams with nets to catch and count organisms that live on the river bottoms, like insects, worms, crayfish, and snails. The critters are grouped into three categories: sensitive, somewhat tolerant, and tough.

Volunteers catch hundreds of organisms at a time in large nets, and carefully record the bugs’ identities and numbers. A stream must have at least 40 different species of critters to pass state standards with an assessment of “fair,” and 70 or more for the highest score of “very good.” Anything below 40 is considered failing, and a stream with fewer than 25 species is considered “very poor.”

StreamWatch’s monitoring program manager Anne Dunckel recruits local volunteers who aren’t afraid of getting wet and digging through the mud and muck to find and count bugs. The fact that only 31 percent of the streams meet state standards is not encouraging, Dunckel said, but also not surprising.

“I’ve seen lots of pieces of the watershed and a dominant portion of the land is affected by human use and management,” Dunckel said. “These land use changes have the capability to impact the way rainfall is funneled into our streams and what it picks up along the way, ultimately degrading the health of our streams.”

Executive director David Hannah noted that the population of the areas tested has grown by more than 15 percent since 2003, so the fact that the water quality hasn’t improved is not entirely shocking, but at least it hasn’t gotten worse.

“It’s somewhat encouraging that, despite population growth, there’s been no noticeable change in water quality,” Hannah said.

As for how exactly to go about improving the waterways, Hannah said a specific plan isn’t in place. StreamWatch works closely with other local groups like the Rivanna Conservation Society and Master Naturalists, but ultimately the nonprofit’s mission is to monitor the streams, provide data for the Virginia Department of Environmental Quality (DEQ), and spread local awareness about the importance of water quality.

Hannah noted that the DEQ’s manpower is limited, and this group of local volunteers is providing data that the state otherwise wouldn’t have access to. StreamWatch is the only local group sending benthic data to the DEQ, and the agency uses the data as if it were its own when evaluating statewide water quality and discussing improvement implementation plans.

“There’s more environmental interest and awareness here than in other parts of the state,” Hannah said. “But we wish it were greater, and we want local communities to use our data, too.”