G.W. Kapple J. R. Freckleton T. J. Durbin 1978 The Salinas Valley ground-water basin is in central coastal California. The ground-water basin extends from Monterey Bay southeastward along the Salinas River to San Ardo, a distance of about 70 miles, and has a maximum thickness of about 2,000 feet. Annual recharge to the ground-water basin, which is derived mostly from the Salinas River, is about 290,000 acre-feet. Annual discharge, which is mostly from pumpage but also includes the consumptive use of ground water by riparian vegetation along the Salinas River, is about 507,000 acre-feet. About 45 percent of the pumpage, or about 217,000 acre-feet of water annually, returns to the ground-water system. A system of interacting hydrologic models was developed for the Salinas Valley. These models include the small-stream model, river model, two-dimensional ground-water model, and three-dimensional ground-water model. The small-stream model simulates ground-water recharge from small streams that are tributary to the Salinas River. The river model simulates ground-water recharge from the surface-water discharge in the Salinas River. The two-dimensional and three-dimensional ground-water models simulate hydraulic head in the ground-water basin. (Woodard-USGS) application/pdf 10.3133/wri78113 en Water Resources Division, U.S. Geological Survey, Two-dimensional and three-dimensional digital flow models of the Salinas Valley ground-water basin, California reports