Assessing stream health in Virginia with biology and chemistry
WMRA Public Radio — by Randi B. Hagi — June 3, 2025
"How do government and nonprofit agencies assess water quality? How do they know what effects a storm or agricultural practice has on stream health? WMRA's Randi B. Hagi tagged along on a demonstration and filed this report.
[stream running, insects and birds calling]
War Branch is a small stream that winds through the poultry, beef, and crop land of Rockingham County before joining Smith Creek, a tributary of the North Fork of the Shenandoah River. It's the site of a monitoring station where the U.S. Geological Survey is studying how farm conservation practices – such as cover crops and fertilizer management – affect water quality. The fact that it's a relatively small watershed makes it unique to study.
It's draining about 10 square miles of land area up above us. So that's still a lot that can happen in that area. A lot of farms, a lot of different activities. But most of our longer-term monitoring networks are in larger rivers and streams – think hundreds of square miles. … It's really hard in those systems to identify specific activities causing changes in the stream chemistry.
Jimmy Webber
Jimmy Webber, the Chesapeake Bay associate coordinator for the USGS, led a group of 20-some attendees on a field trip to see the monitoring station. The trip was a part of the Choose Clean Water Conference held in Harrisonburg in mid-May. The group walked through hayfields and pastures down to the grassy stream banks of the War Branch site. Established a year ago, it's one of five watersheds in the ongoing study. The others are in Delaware, Maryland, and Pennsylvania.
Monitoring equipment that lies in the stream collects data and uploads it to an online database about every 15 minutes. It's a metal tube with smaller cylindrical sensors extending from the end – it kind of looks like a cross between a caulk gun and a gatling gun. A tiny motorized brush sweeps off the end of the sensors before each data reading. As Hydrologic Technician Laura Yates explained, the sensors are gauging metrics including water height, turbidity, and dissolved oxygen. She pointed out another one to the group. . ."