Future Northern Virginia Reservoir to Hold 17 Billion Gallons of Water

Aerial image of Vulcan Quarry



Over the next 70 years, a rock quarry in Lorton will be transformed into a water storage reservoir.

Talk about long-term planning.

Fairfax Water and Vulcan Materials Company recently signed an agreement that’s been in the works since 2000. It involves a phased conversion of Vulcan’s quarry to a Fairfax Water reservoir ultimately capable of holding up to 17 billion gallons of water, which is needed as our population will continue to grow.

“Between 2010 and 2040 the population served by Fairfax Water, including both retail and wholesale areas, will increase by over 650,000 residents and nearly 550,000 employees working in the area,” said Philip Allin, chairman of Fairfax Water.


Reservoir Plans

The reservoir will be developed in two stages:

  • By 2035: the northern part of the quarry will be transferred to Fairfax Water after quarry operations stop in that portion of the property;
  • By 2085: the remainder of the quarry will be transferred to Fairfax Water after quarry operations cease entirely.

aerial view of vulcan quarry


About Water in Our Region

Three utilities — the Washington Aqueduct, the Washington Suburban Sanitary Commission, and Fairfax Water — are the primary suppliers of the region’s drinking water. They work together on supply management through something called the Cooperative Water Supply Operations on the Potomac (Co-Op). The Co-Op systems produce an average of 370 million gallons of drinking water per day, with the capacity to produce 600 million gallons per day during peak demand.

The Co-Op uses surface water as the primary source of drinking water. The Potomac River provides approximately 78 percent of the water used in the region to about 4.5 million people. The remaining 22 percent is drawn from the Occoquan Reservoir in Virginia and the Patuxent River in Maryland, with a nominal amount drawn from groundwater.

chart of water sources: 78% from potomac river

The region uses two reservoirs for daily use and as two backup supplies during droughts when the Potomac River stream flow is low. The new reservoir will provide significant additional storage in case we experience a regional drought.

“There are a lot of positives that will come out of this agreement for current and future generations,” said Vulcan’s William Duke. “The region has a continued supply of essential construction materials – crushed stone – required to build and maintain our economy and it provides for another basic resource – water – that is also required to sustain our economy.  This is a great example of a public-private partnership that will bring benefits to the community and future generations.”


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