Study: Eastern Shore groundwater under long-term pressure despite stabilization

A new report from the U.S. Geological Survey finds that groundwater on Virginia’s Eastern Shore remains under long-term stress, even as water levels have stabilized in recent years.

The study, conducted in cooperation with the Virginia Department of Environmental Quality, examined how water moves through underground aquifers and how decades of pumping have altered the region’s water supply.

Researchers say the Eastern Shore relies almost entirely on groundwater for drinking water, agriculture, and industry, making it especially vulnerable to overuse.

Unlike other parts of Virginia, our peninsula has no significant freshwater rivers or reservoirs. Instead, it depends on a shallow freshwater system surrounded by saltwater from the Chesapeake Bay and Atlantic Ocean.

The report found that only a small fraction of rainfall makes its way into the deeper aquifers that supply most wells. On the Eastern Shore, less than two percent of recharge reaches the primary confined aquifer, limiting how quickly the system can replenish itself.

Decades of pumping have already changed how groundwater flows beneath the region. Instead of moving naturally outward toward rivers and the coast, water is now being pulled downward and toward major pumping centers.

That shift raises ongoing concerns about saltwater intrusion, where saltwater moves into freshwater aquifers, as well as the long-term sustainability of the water supply.

While groundwater levels have generally stabilized since around 2010 due to reduced large-scale withdrawals, the report notes that overall groundwater storage continues to decline slowly. That means more water is still being removed than replaced over time.

Officials say the findings reinforce the importance of groundwater management rules already in place, including permitting requirements for large users.

The report also warns that future increases in demand, including potential industrial growth, could place additional strain on the system if not carefully managed.

For now, researchers say the Eastern Shore’s water supply remains usable, but caution that its long-term reliability depends on maintaining a balance between use and recharge.