It is on Arroyo Valle (Spanish for "creek of the valley") in the Diablo Range. The lake is formed by Del Valle Dam, completed in 1968 (56 years ago) (1968).[2]
The lake and dam are part of the California State Water Project, as part of the South Bay Aqueduct. The lake serves in part as off-stream storage for the South Bay Aqueduct. The capacity of the lake is 77,000 acre-feet (95,000,000 m3), however, the lake has a flood storage of 25,000 to 40,000 acre-feet (31,000,000 to 49,000,000 m3). Thus normally stores 37,000 to 52,000 acre-feet (46,000,000 to 64,000,000 m3). The lake is a popular destination for hikers, bikers, and boaters.
The dam is 230 feet (70 m) high and 880 feet (270 m) long. Its crest elevation is 773 feet (236 m). The dam contains 4,150,000 cubic yards (3,170,000 m3) of earth fill.[1]
