Five Northern Virginia counties are under a drought watch advisory because of “abnormally low precipitation over the last two weeks,” the Virginia Department of Environmental Quality said. The advisory encompasses Arlington, Fairfax, Fauquier, Loudoun, and Prince William counties.
A drought watch is issued to increase awareness that a drought may occur.
The state calling on residents to minimize water use and repair any leaks to protect water supplies as it works with local governments and public water works officials to make sure conservation and drought response plans are followed.
The NoVA counties are among 13 in the state under a watch advisory. The other counties under the drought watch advisory are both Eastern Shore counties, Accomack and Northampton, as well as Charles City, Hampton, James City, York, New Kent, and Newport News.
A drought warning advisory — which means a drought is imminent — is posted for seven other counties: Augusta, Clarke, Frederick, Page, Rockingham, Shenandoah, and Warren.
Virginia uses four indicators to determine the severity of a drought: precipitation deficits, reservoir storage, stream flows, and groundwater levels.
While there is little rain in the forecast, Northern Virginia’s precipitation is at more than 95 percent of a normal year. The Eastern Shore, on the other hand, has seen only 83 percent of its normal rainfall.
The state said that all major water supply reservoirs, including Occoquan Reservoir and Lake Manassas, “remain within normal ranges, except for Skidmore Fork Lake (Switzer Lake), in Harrisonburg.”
But streamflows are below where they should be.
“Streamflow over the past 14-day period has shown widespread declines throughout the Commonwealth. Ranking as ‘Normal’ flows are currently below the 25th percentile for eight of the 11 drought evaluation regions including; Shenandoah, Northern Coastal Plain, Northern Piedmont, Chowan, York James, Upper James, Northern Virginia, and Roanoke,” said a Virginia Drought Monitoring Task Force status report that prompted the advisories.
Groundwater levels are compared to historic level statistics. Those that measure “below the 5th percentile for all historic levels will be defined as drought emergency conditions,” the state’s monitoring and response plan said.
In NoVA, groundwater indicators are at that emergency level, the latest report indicates.
“Declines in surface and groundwater indicators have continued throughout the past fourteen-day period, with near record low observations at some stations within Northern Virginia and Shenandoah,” the August 24 report said.
The state is continuing to monitor for the possibility of a drought. Its monitoring task force meets again September 7.
Feature image of drought map, courtesy Virginia Department of Environmental Quality
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