Vanishing Water? From the Rural Crescent to the Occoquan Reservoir by Elizabeth Ward

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.

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 Comprehensive Plans 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 process as we plan for the future of our county.

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 protect the water supply of the whole Rural Crescent.