La Grange Dam

The La Grange Dam is a masonry-gravity diversion dam on the Tuolumne River near La Grange, California. The dam was completed in 1893 by the Turlock Irrigation District and Modesto Irrigation District in an effort to divert water into their canal systems for local farmers.

The La Grange Dam is two miles (3 km) downstream of the New Don Pedro Dam and not only serves to regulate its outflows but diverts water from the Don Pedro's much larger reservoir into two canals on either side of the river. Each year, an average of 885000 acre.ft of water is diverted. About 575000 acre.ft goes through TID's canal to Turlock Lake and another 310000 acre.ft goes through MID's canal to Modesto Reservoir. Nearly all of this water irrigates crops in the Turlock and Modesto Irrigation Districts. Another 230000 acre.ft goes to San Francisco's Hetch Hetchy Water and Power. And, finally, about 780000 acre.ft of water is delivered to the Tuolumne River channel to maintain flows in the 52 miles (84 km) of the Lower Tuolumne River through its confluence with the San Joaquin River and then into the Sacramento-San Joaquin Delta.

The La Grange Dam also diverts water to a small 4 MW hydroelectric power station above the east bank of the Tuolumne River that is operated by the Turlock Irrigation District.