Figure 1. Basic hydrology in eastern North Carolina. Average annual rainfall ranges from 44 to 60 inches, evapotranspiration (ET) is 32 to 40 inches, deep groundwater recharge is 1/2 to 2 inches, and drainage outflow is 12 to 20 inches. Drainage outflow ultimately returns to the ocean through the surface water system, incl. drainage ditches, streams, rivers