High Quality Content by WIKIPEDIA articles! New Don Pedro Dam, often known simply as Don Pedro Dam, is an earthen embankment dam across the Tuolumne River, about 2 miles (3.2 km) northeast of La Grange, California in the United States. The dam serves mainly for irrigation water storage, flood control and hydroelectricity production, and impounds Don Pedro Reservoir in the foothills of the Sierra Nevada. The dam was completed in 1971 after four years of construction.