Santa Anita Dam

Santa Anita Dam, also known as Big Santa Anita Dam, is a concrete thin arch dam on Santa Anita Creek in the San Gabriel Mountains of Los Angeles County, California. Owned by the Los Angeles County Flood Control District, the dam serves for flood control, water conservation and debris control. The dam is 225 feet (69 m) high and 612 feet (187 m) long, holding 858 acre-feet (1,058,000 m³) of water with a maximum capacity of 1,028 acre⋅ft (1,268,000 m³). The catchment area for the dam is 10.8 square miles (28 km²). The dam was built between 1923 and 1927.^[1] The dam has three valves that control releases of stormwater.^[2]

Santa Anita Dam
Location	Sierra Madre, California
Coordinates	34.1836164°N 118.0195111°W / 34.1836164; -118.0195111
Construction began	1924
Opening date	1927
Construction cost	$17 million
Owner(s)	Los Angeles County Flood Control District
Dam and spillways
Type of dam	Concrete thin arch
Impounds	Santa Anita Creek
Height	225 ft (69 m)
Length	612 ft (187 m)
Width (base)	61.5 ft (18.7 m)
Reservoir
Creates	Santa Anita Reservoir
Total capacity	1,028 acre⋅ft (1,268,000 m3)
Catchment area	10.8 sq mi (28 km2)
Surface area	17 acres (6.9 ha)

The dam is situated in the steep San Gabriel foothills, north of Sierra Madre and Arcadia. It is located just north of the boundary of the Angeles National Forest. The dam is visible from Santa Anita Canyon Road, which runs along the west slope of the Santa Anita Canyon and provides access into trails further upstream along Santa Anita Creek. The viewing window for the dam is very short, only about a half-mile; the access road which runs down into the canyon from Santa Anita Canyon Road is closed to the public. However, the First Water trail, which leads downstream from Chantry Flat along the creek, is said to provide access to the reservoir.

Since the 1990s the maximum allowed storage of water has been restricted, to ensure that the dam will not collapse due to seismic instability. This has partially caused rapid silting of the reservoir and sediment removal was started in mid-2009. The reservoir was drained and about 6,750,000 cubic yards (5,160,000 m³) of sediment were removed.

A staged rescue at the dam was broadcast in November 1958 as an episode of the syndicated U.S. television series Rescue 8 titled "The Chasm".

References

1. "Santa Anita Dam Riser Modification and Reservoir Sediment Removal Project Environmental Impact Report" (PDF). Los Angeles Department of Public Works. May 2008. Archived from the original (PDF) on January 5, 2024. Retrieved August 10, 2010.
2. Sahagún, Louis (January 24, 2023). "January storms leave L.A. County flood-control dams at risk of overflowing". Los Angeles Times. Retrieved March 19, 2023.

External links

• Image of workers walking on the face of the Santa Anita Dam during construction, California, circa 1926. Los Angeles Times Photographic Archive (Collection 1429). UCLA Library Special Collections, Charles E. Young Research Library, University of California, Los Angeles.