San Antonio Dam is an

embankment Embankment may refer to: Geology and geography * A levee, an artificial bank raised above the immediately surrounding land to redirect or prevent flooding by a river, lake or sea * Embankment (earthworks), a raised bank to carry a road, railwa ...

flood control and debris dam on San Antonio Creek in

San Bernardino County San Bernardino County (), officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181, ...

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 ...

, about north of

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

. The dam was authorized by the Flood Control Acts of 1936 and 1938 as part of a major program to provide flood protection in the

Santa Ana River The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting through ...

system. Construction began in April 1952 and finished in May 1956. The dam controls runoff from a rugged catchment area of 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 ...

. The dam was built by the Los Angeles District of the

U.S. Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

. The dam is long, high above the foundation, and above the riverbed. The main embankment contains of material. The reservoir behind the dam is usually dry, but can fill with up to of water after large flooding events. A concrete overflow spillway on the west side prevents overtopping and drains to the San Antonio and

Chino Creek Chino Creek is a major stream of the Pomona Valley, in the western Inland Empire region of Southern California. It is a tributary of the Santa Ana River. Geography Although the main stem is short at about , it drains an extensive basin of from t ...

channels, which were lined with concrete between 1956 and 1960 to protect against such an event. A project has been underway since 2012 to remediate seepage problems at the toe of the dam during heavy rainstorms. The dam is considered a high hazard structure.

References

{{reflist Dams in California

See also

References