The Shadow
The Norfolk District of the U.S. Army Corps of Engineers, in cooperation with the Virginia Department of Environmental Quality and the Virginia Department of Game and Inland Fisheries, will conduct a “pulse release” on Tuesday, Aug. 17, at the Gathright Dam.
The pulse release, a controlled release of water which simulates storm events, is expected to raise water levels downstream in the Jackson River by up to four feet and up to two feet in the upper James River.
Water levels will remain several feet below flood stage.
In some areas, the rate of the river rise may exceed one foot per hour, and people who live near or recreate on the rivers are cautioned to be alert to changing conditions.
The pulse release will begin at 6 a.m. with dam operators gradually increasing outflow of water from 280 to 3,000 cubic feet per second by 9 a.m.
Dam operators will maintain the 3,000 cubic feet per second release for two hours and gradually decrease the water flow from the dam at 11 a.m. By 2 p.m., water flow from Gathright Dam will return to a normal seasonal outflow.
The controlled release of water is being done to test whether or not pulses are effective at removing algae and improving water quality by simulating late-summer and early-fall storm events, a natural variability that has been reduced by the operation of Gathright Dam.
The test is part of a study authorized under Section 216 of the Rivers and Harbors and Flood Control Act of 1970.
The Gathright Dam and Lake Moomaw project, located on the Jackson River 43.4 miles upstream of its confluence with the Cowpasture River, is a multipurpose project authorized by the Flood Control Act of 1946 and is regulated to reduce flood damage at downstream locations, to increase low flows for improvement of downstream water quality and to provide water-based recreational opportunities.
