Pacoima Dam is a concrete
arch dam
An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthe ...
on
Pacoima Creek in the
San Gabriel Mountains, in
Los Angeles County,
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
. The reservoir it creates, Pacoima Reservoir, has a capacity of
Built by the Los Angeles County Flood Control District, which became part of the Department of Public Works, it was completed in 1928. At the time, the 371 foot (113m) high dam was the tallest arch dam in the U.S.
The dam is situated approximately northeast of
Sylmar, above the
San Fernando Valley.
Instrumentation
As construction of Pacoima Dam began, the County of Los Angeles hired Roy W. Carlson as their concrete and soil testing engineer. He developed the world's first strain meter which could be embedded in concrete. He also developed an adiabatic calorimeter and electrical-resistance thermometers to find why the temperature of concrete increased during curing and how best to avoid cracking caused by these stresses.
Earthquake monitoring
The Pacoima Dam withstood, but was damaged by the very strong (>1 ''g'') ground movement which occurred during both the
1971 San Fernando and
1994 Northridge earthquakes. Because of concerns about the stability of the dam and especially its response to potential future earthquakes, the County of Los Angeles, with the technical support of the USGS, began monitoring the dam using continuous GPS.
See also
*
Angeles National Forest
The Angeles National Forest (ANF) of the U.S. Forest Service is located in the San Gabriel Mountains and Sierra Pelona Mountains, primarily within Los Angeles County in southern California. The ANF manages a majority of the San Gabriel Mounta ...
*
List of dams and reservoirs in California
*
List of lakes in California
There are more than 3,000 named lakes, reservoirs, and dry lakes in the U.S. state of California.
Largest lakes
In terms of area covered, the largest lake in California is the Salton Sea, a lake formed in 1905 which is now saline. It occupie ...
References
External links
Image of workers at the bottom of a canyon at the Pacoima Dam site working on wood framing and concrete pouring, 1926.Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the U ...
Photographic Archive (Collection 1429). UCLA Library Special Collections,
Charles E. Young Research Library,
University of California, Los Angeles
The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California S ...
.
Los Angeles County Department of Public Works dams
Arch dams
San Gabriel Mountains
San Fernando Valley
Dams completed in 1929
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