Gathright Dam test pulse improves Jackson River's water quality

Posted August 19, 2011
By Kerry Solan, U.S. Army Corps of Engineers Public Affairs

08/19/2011 - NORFOLK, Va. — A surge of water released from Gathright Dam, simulating a storm event on the Jackson River, did exactly what the Virginia Department of Environmental Quality and Norfolk District, U.S. Army Corps of Engineers hoped it would: improve the river’s water quality.

The results of the August 2010 surge, or test pulse, recently released by the DEQ, indicate the pulse raised dissolved oxygen levels in the river, scoured excess oxygen-consuming algae and "slightly improved" the aquatic habitat Jackson River below Covington.

"We are monitoring the Jackson River before and during test pulses to establish current baseline water quality conditions," said Jason Hill, an environmental scientist with the Virginia Department of Environmental Quality. "We will be using this baseline data to track any environmental changes that result from these simulated storm events."

The Department of Environmental Quality requested the test pulse from Norfolk District, which owns and operates the Gathright Dam. The dam, located on the Jackson River, creates Lake Moomaw.

The eight-hour test pulse peaked at 3,000 cubic feet per second for two hours.

"The dam operators did a great job mimicking a natural storm event," said Larry Ives, Norfolk District civil engineer.

The results of the test pulse are being used in an ongoing feasibility study at the dam. The study will determine whether a change to current low-flow augmentation operations at the dam can improve the overall water quality and ecological resources in the lower Jackson River without affecting the existing fisheries in Lake Moomaw and the trout fishery below the dam.

Another pulse is scheduled for late September. The feasibility report will be completed in 2012.