What causes salty drinking water?

On the Eastern Shore, salt can get into the drinking water in two ways. Coastal flooding can get salt into the groundwater right below the surface, and over-pumping water wells can pull seawater from the ocean into deep underground aquifers. 

High tide flooding and storm surges bring saltwater onto land. Usually, drainage ditches empty water into creeks to keep the land around them drier, but dry ground is like a sponge. When creeks by the ocean flood, saltwater can travel back up drainage ditches and soak into the ground.  

Fresh water comes from rain that filters down into the earth. This water collects underground in small spaces between rock and soil, which is called an aquifer. Wells use a pump to pull this water up. If a well pumps out too much freshwater, sea water moves in to fill the space.

What causes wells to dry up? 

The Eastern Shore gets about 44 inches of rain every year, and only 5-6 inches sink into the shallow, unconfined aquifer. Less than 1 inch of water filters down to the confined Yorktown-Eastover aquifer each year, which is primarily used by industries and agriculture. When more water is pumped out than comes into the aquifer, wells can eventually run dry.

What does this mean for the future?

Only a few towns on the Eastern Shore currently have salty drinking water. In the future, higher flooding and too much well pumping may mean more salt in the Yorktown-Eastover aquifer.

By 2080, models showing a drier climate estimate that the Eastern Shore’s shallow aquifer could lose over 14 billion gallons of freshwater, which is the amount of water the Eastern Shore uses in 2.5 years (Hesamfar et al. 2026). 

We can prevent some of the ways salt gets into drinking water and reduce pumping too much water from the deep aquifer.

What can be done?

Improve Ditch Planning

Filling or redirecting ditches that connect to tidal creeks is another option to keep storm surge from flooding fields with saltwater.

Create Natural Flood Barriers

Conserving and creating natural flood barriers can help too. Natural barriers against flooding include salt marshes, dunes, and native vegetation. They absorb wave energy and limit erosion, which keeps saltwater from getting farther into the soil.

Get Involved in water management

Laws that stop too much groundwater pumping can protect the aquifers from saltwater getting pulled in. The State Water Control Board designated the Eastern Shore as a Groundwater Management Area, which means that using groundwater requires a permit from the VA Department of Environmental Quality. The Eastern Shore Groundwater Committee meets monthly and offers virtual public participation.
To learn more and get involved with the Groundwater Committee, click here.
To learn more and contact the advisory committee, click here.