A severe drought in the 1930s demonstrated that Melones Reservoir, by itself, was too small to meet all the irrigation demands. The OID sank 25 deep wells between 1931 and 1938 to make up for the shortfall, but this depleted the local groundwater at an unsustainable rate. SSJID was better supplied throughout the 1930s, in part due to less water-intensive crops, but started experiencing shortages by the early 1940s. In 1948 the districts joined to increase water storage on the Stanislaus River by constructing the Tri-Dam Project, consisting of Donnells and Beardsley dams on the Middle Fork, Tulloch Dam between the existing Goodwin and Melones dams, and Columbia Dam below the junction of the Middle and North Forks (this fourth site was later dropped from the proposal). The districts had also contemplated building a bigger 1.1 million acre foot (1.4 km3) reservoir to replace the Melones Reservoir, but this project also never made it past the drawing board.