The purpose of irrigation is to grow crops. Unlike some states in the Midwest, California does not receive enough rain to grow during the summer, rendering irrigation a necessity. The water that SSJID utilizes comes from the Stanislaus River watershed; water is stored in the reservoirs behind the Tulloch, New Melones, Beardsley, Goodwin, and Donnells dams. Irrigation season runs from approximately March 15 to October 15, depending on the weather.