The most important sources of ground water for Wilson County, North Carolina are (1) the sand beds of the Cretaceous aquifer system in the Coastal Plain section in the eastern part of the county and (2) the bedrock aquifer system in the Piedmont section in the western part of the county.
The Cretaceous aquifer is recharged from leakage through overlying beds composed primarily of clay. This leakage rate is estimated to average about 67,000 gallons per day per square mile (100 cubic metres per day per square kilometre). Present withdrawals from the Cretaceous aquifer in the county average about 740 gallons per day per square mile (1.1 cubic metres per day per square kilometre), or about 1 percent of the amount of water available to the aquifer. Most of the withdrawals from the Cretaceous aquifer are in the Saratoga-Stantonsburg area in eastern Wilson County around which a widespread decline in water level has occurred in the aquifer. Since 1942, the rate of decline has averaged nearly 1.5 feet (0.45 metre) per year in the center of the pumping area.
Individual wells can yield as much as 500 gallons per minute (32 litres per second) in the easternmost part of the county where the aquifer is thickest, but wells pumped continually at this rate would increase the rate of water-level decline throughout the aquifer.
