The Castle Hayne aquifer is an eastward sloping and thickening wedge of limestone and sandstone, located in a 12,500 sq mi area in the eastern part of North Carolina. The Castle Hayne aquifer is the major source of freshwater for much of coastal North Carolina where the aquifers underlying the Castle Hayne contain saltwater. A regional study of the Castle Hayne aquifer was conducted to provide definitive information on the declines in water levels and of saltwater intrusion in the area. A series of geohydrologic maps produced from the study, show the altitude of the top of the aquifer, location of saltwater in the aquifer, aquifer thickness, aquifer transmissivity, and confining-unit thickness. The history of groundwater pumpage can be compared with historical water levels in the aquifer. These geohydrologic, pumpage, and water level data can be used to develop estimates of aquifer and confining-unit hydraulic coefficients and to develop a groundwater flow model for the Castle Hayne aquifer. The model will increase the understanding of the groundwater flow system and also can be used to assess various groundwater development scenarios for the entire Castle Hayne aquifer.
