Act Now to Ensure the Rural Crescent will have Water

We are at a crossroads in Prince William County. The Board of County Supervisors is considering plans for development of the Rural Crescent, an area completely dependent on groundwater to supply its homes. The groundwater level in the only monitoring well in the Rural Crescent has been falling since 2004. This is a warning that we are depleting the aquifer.

The Tidewater area of Virginia, dependent on the groundwater from the Potomac Aquifer, has had falling groundwater levels for decades. In some areas groundwater has fallen up to 200 feet and are at risk of running out of water. In the 1990’s a law was passed to control groundwater use by regulating withdrawals of groundwater in the Tidewater. This program regulates withdrawals while monitoring the aquifer through nearly two thousand wells and boreholes used to measure water level and quality. They are still working to reach sustainable water use.

The Rural Crescent has one monitoring well to monitor the water supply to more than 7,800 dwellings in the Rural Crescent. The data is publicly available, but that well is not part of any state or local program. The groundwater level in that one well in the Rural Crescent has been falling since 2004, and again this is a warning that we are using up the groundwater.

Adding development to the Rural Crescent without a program to measure and monitor the groundwater that the whole Rural Crescent depends on is like driving with your eyes closed. There is no surface water to turn to if the wells fail, groundwater is all that is available. The public water suppliers in the Washington area are already struggling near the limits of their capacity and facing extraordinary costs, and so cannot be expected to come to our rescue.

In 2018, the Virginia Legislature amended the comprehensive planning process (§§ 15.2-2223 and 15.2-2224 of the Code of Virginia) to include the requirement that county the Comprehensive Plans plan ensure the continued availability, quality and sustainability of groundwater and surface water resources on a County level. Prince William needs to carefully carry out that goal process as we plan for the future of our county.

Groundwater levels are determined by how much groundwater is being used and by how much groundwater is being recharged. Development of an area impacts both use and recharge. Increases in impervious cover from roads, pavement and buildings reduces recharge, and development brings more people and water use. Slowly, over time, the water table falls as it has been doing since 2004, because the water supply is inadequate to the current demand.

The Prince William County Board of Supervisors should immediately begin a program of measuring groundwater levels and flow in the Rural Crescent. New monitoring wells need to be added to the rural area to assure adequate and sustainable groundwater for current residents as required by law before approving any new development that would put the Rural Crescent groundwater at greater risk.

Once we have a program and monitoring data, Prince William County needs to:

• Develop a rural area water-sustainability model of the groundwater systems;
• Identify the relationships between groundwater withdrawals and base flow in streams, and the effects of new or increased groundwater withdrawals;
• Develop tools and data for the preservation of water resources within the Rural Crescent.

 It is not too late to prevent an Eastern Shore type of problem from befalling the water supply of the whole Rural Crescent, but we need to act now to ensure that we have sustainable water.