Last week, the Virginia Department of Environmental Quality issued a drought warning advisory for our area. A drought warning advisory indicates a significant drought is imminent for the Northern Virginia Region which includes Fauquier, Loudoun, Prince William, Arlington, and Fairfax counties and for the Shenandoah region, which includes Augusta, Rockingham, Shenandoah, Frederick, Page, Warren, and Clarke counties. Fauquier County WSA water systems have already implemented Mandatory Outdoor Water Usage Restrictions for their customers.
![]() |
from DEQ |
Virginia generally receives 44 inches of precipitation each year and is historically considered “water rich." However, droughts are not uncommon, and Virginia has a history of multi-year droughts, including the record-breaking droughts of 1999–2002, 2007–2008, and 2010–2012. Virginia also experienced a short, high-impact drought during the late summer and fall of 2023 that was a primary factor in several major wildfires, including the Matts Creek Fire in the Jefferson National Forest; and the seasonal drying out of what had been perennial streams.
Droughts in Virginia can have far-reaching impacts on
agriculture, water availability, and wildfires. Drought conditions can also
develop rapidly, especially when the lack of rain and high temperatures combine
to quickly increase the loss of water from the landscape via evapotranspiration.
There is increased regional awareness of how these rapid-onset droughts,
sometimes referred to as "flash droughts,"
can cause significant agricultural economic impacts and supply concerns to
other water users-residential, commercial and industrial.
Flash drought is simply the rapid onset or intensification
of drought. It is set in motion by lower-than-normal rainfall , accompanied by
abnormally high temperatures, winds, and radiation. Together, these changes in
weather can rapidly alter the local climate. Higher temperature increases evapotranspiration—the
process by which water is transferred from the land to the atmosphere by
evaporation from the soil and by transpiration from plants—and further lowers
soil moisture, which decreases rapidly as drought conditions continue.
Following the guidance in the Virginia Drought Assessment
and Response Plan, the Virginia Drought Monitoring Task Force (DMTF) monitors
and evaluates hydrologic and water supply conditions for DEQ . The DMTF
is also responsible for making recommendations for Drought Stage
declarations. These declarations are intended to facilitate communities’
preparation for a drought. Drought warning responses are called for when the onset of a
significant drought event is imminent.
DEQ uses the indicators listed below to gauge the presence
and severity of hydrologic drought across the 13
Drought Evaluation Regions. According to the Virginia DMTF, a work
group of state and federal agencies coordinated by DEQ, the primary factors
contributing to the advisory are low precipitation across the state over the
past 90 days, low stream flows and low groundwater levels compared to previous
levels for this time of year.
Each day, DEQ compares groundwater levels and streamflow
records from “real-time” continuous recording wells and gaging stations across
Virginia to long-term records (at least 10 years) for the current month.
For groundwater, daily records are compared; for streamflows, the average of
the previous seven days’ flow records are compared.
A drought warning indicates that a drought is imminent. So
local governments and and water utilities are advised to implement restrictions
on water use- both voluntary and mandatory. Rainfall deficits, high temperatures and high
outdoor water use have contributed to the increasing drought warning signs. Drought
Indicators tracked by DEQ (and key to Drought Map) are:
- Precipitation
(Prcp)
- Groundwater
Levels (GW)
- Streamflow
(Flow)
- Reservoir Levels (Res)
![]() |
DEQ |
No comments:
Post a Comment