Several water-related problems are associated with economic development of northeast North Carolina. The solution to these problems depends in part on adequate knowledge of the hydrology of this 8,930 square mile coastal area. Average annual precipitation on the area is about 50 inches. Of this amount, about 34 inches returns to the atmosphere by evapotranspiration, about 15 inches leaves the area as runoff, and about one inch leaves through ground-water outflow. No large stream originates within the area, but major streams entering from the north and west bring in three times as much streamflow as originates within the study area. The flat, low-lying terrane does not offer opportunities for extensive development of surface-water supplies through the use of reservoirs. Much of the surface water is contaminated by saltwater from the ocean. Ground water occurs in three major aquifers, all of which contain both freshwater and saltwater.