San Dimas Dam is a concrete

gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it. ...

Los Angeles County Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is the ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. The dam and its flood control basin/reservoir are in the

San Gabriel Mountains The San Gabriel Mountains ( es, Sierra de San Gabriel) are a mountain range located in northern Los Angeles County, California, Los Angeles County and western San Bernardino County, California, United States. The mountain range is part of the Tr ...

and within the

Angeles National Forest The Angeles National Forest (ANF) of the United States Forest Service, U.S. Forest Service is located in the San Gabriel Mountains and Sierra Pelona Mountains, primarily within Los Angeles County, California, Los Angeles County in southern Calif ...

. The dam is currently operated by the Los Angeles County Department of Public Works but was originally built by the Los Angeles County Flood Control District in 1922. The dam controls flooding from San Dimas Creek, a major San Gabriel Mountains drainage and tributary of the San Gabriel River. As a flood control facility the San Dimas Reservoir is dry for most of the year, only storing water after significant winter storms. The regulation provided by the dam allows for the efficient diversion of floodwaters from San Dimas Wash to

Puddingstone Reservoir Puddingstone Reservoir is a 250-acre (1 km²) artificial lake northeast of the interchange between the Orange Freeway (State Route 57) and the San Bernardino Freeway (Interstate 10) in Los Angeles County, California, United States. Activities ...

, which protects the San Dimas area of the

San Gabriel Valley The San Gabriel Valley ( es, Valle de San Gabriel) is one of the principal valleys of Southern California, lying immediately to the east of the eastern city limits of the city of Los Angeles, and occupying the vast majority of the eastern part ...

History

After the flood of 1914 and the creation of the Los Angeles Flood Control District in 1915, the District launched a flood control and water conservation program. The program initiated the construction of 14 dams throughout Los Angeles County, one of which was the San Dimas Dam. Although the dam was originally built by the Los Angeles Flood Control District in 1922, the dam is currently operated by the Los Angeles County Department of Public Works. In 1984, the planning and operational activities of the dam were transferred from the Flood Control District to the Department of Public Works in an operational agreement. According to the Los Angeles County Department of Public Works website, "Public Works Flood Maintenance and Water Resources Divisions, respectively, oversee its maintenance and operational efforts."

Geography

The San Dimas Dam is located in Los Angeles County, California within the Angeles National Forest. The dam is 130.9 feet (39.9 m) high and 339.8 feet (103.6 m) long, with a storage capacity of 1,515 acre feet (1,869,000 m³) of water. The dam is surrounded by the San Gabriel Mountains and has an incoming flow from the San Dimas Creek. The dam controls flooding from San Dimas Creek, a major San Gabriel Mountains drainage and tributary of the San Gabriel River. The dam diverts floodwater to

, protecting the area in and around San Dimas.

Infrastructure and Water Management

The dam is a concrete gravity dam and is 130.9 feet (39.9 m) high and 339.8 feet (103.6 m) long, with a storage capacity of 1,515 acre feet (1,869,000 m³) of water. The dam controls flooding from San Dimas Creek, a major San Gabriel Mountains drainage and tributary of the San Gabriel River. As a flood control facility, the San Dimas Reservoir is dry for most of the year, only storing water after significant winter storms. The regulation provided by the dam allows for the efficient diversion of floodwaters from San Dimas Wash to

, which protects the San Dimas area of the

. The dam's main purposes are for irrigation, flood control, and water supply.

References

{{LA County dams Los Angeles County Department of Public Works dams Gravity dams San Gabriel Mountains San Gabriel River (California) Angeles National Forest Dams completed in 1922 1922 establishments in California

History

Geography

Infrastructure and Water Management

See also

References