|Location||Castaic, Los Angeles County, California|
|Primary inflows||West Branch California Aqueduct|
|Primary outflows||Castaic Creek|
|Basin countries||United States|
|Water volume||320,000 acre⋅ft (390,000,000 m3)|
|Surface elevation||1,519 feet (463 m)|
Castaic Lake is a reservoir formed by Castaic Dam on Castaic Creek, in the Sierra Pelona Mountains of northwestern Los Angeles County, California, United States, near the town of Castaic.
The California Office of Environmental Health Hazard Assessment has issued a safe advisory for any fish caught in Castaic Lake and Castaic Lagoon due to elevated levels of mercury and PCBs.
The 320,000 acre⋅ft (390,000,000 m3) lake, with a surface elevation of approximately 1,500 feet (460 m) above sea level, is the terminus of the West Branch California Aqueduct, though some comes from the 154-square-mile (400 km2) Castaic Creek watershed above the dam. Castaic Lake is bisected by the Elderberry Forebay Dam, which creates the adjacent Elderberry Forebay. The aqueduct water comes from Pyramid Lake through the Angeles Tunnel and is used to power Castaic Power Plant, a pumped-storage hydroelectric facility on the northern end of the forebay. Water is mostly powering the turbines, rather than being pumped by them.
Castaic Lake State Recreation Area is a state park located in northwestern Los Angeles County near the community of Castaic, north of Santa Clarita. It is controlled by the California Department of Parks and Recreation. The recreational area is adjacent to the Angeles National Forest. The 4,224-acre (1,709 ha) park was established in 1965. The area encompasses Castaic Lake. Primary access is via Interstate 5 at exits 176A and 176B at the town of Castaic.
Water from the lake is distributed throughout the northern portion of the Greater Los Angeles Area. Some water is released into Castaic Lagoon below the dam, to maintain its water level for recreation. Castic Lagoon drains into Castaic Creek, which flows south until it meets the Santa Clara River, a few miles west of Santa Clarita.
Castaic Lake has a lower lagoon with a swim beach that is open from Memorial Day weekend to Labor Day weekend annually. This lake also offers bass fishing in the upper and lower lake year-round and float tube fishing in the lower lake.
Castaic Lake was one of the main filming locations for the Mighty Morphin Power Rangers series. Many of the action scenes were recorded here.
Castaic Lake was the starting point for The Amazing Race 26 on November 12, 2014. NBC's Fear Factor was also shot there.