The Imperial Diversion Dam (National ID # CA10159) is a concrete slab and buttress, ogee weir structure across the California/Arizona border, northeast of Yuma. Completed in 1938, the dam retains the waters of the

Colorado River The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...

into the

Imperial Reservoir The Imperial Reservoir is an lake, artificial lake formed by the construction of the Imperial Diversion Dam across the Colorado River in the Lower Colorado River Valley of Imperial County, California, and Yuma County, Arizona. It is northeast ...

before desilting and diversion into the All-American Canal and the Gila Project aqueduct. Between 1932 and 1940, the

Imperial Irrigation District The Imperial Irrigation District (IID) is an irrigation district that serves the Imperial Valley and a large portion of the eastern and southern Coachella Valley in the Colorado Desert region of Southern California. Established under the Stat ...

(IID) relied on the Inter-California Canal and the Imperial Canal and Alamo River.

Background

The Imperial Dam was built with three sections; the gates of each section hold back the water to help divert the water towards the desilting plant. Three giant desilting basins and seventy-two 770 ft (230 m) scrapers hold and desilt the water; the removed silt is carried away by six sludge-pipes running under the Colorado River that dump the sediment into the California sluiceway, which returns the silt to the Colorado River. The water is now directed back towards one of the three sections which divert the water into one of the three channels. About 90% of the volume of the Colorado River is diverted into the canals at this location. Diversions can top per second, roughly the volume of the

Susquehanna River The Susquehanna River ( ; Unami language, Lenape: ) is a major river located in the Mid-Atlantic (United States), Mid-Atlantic region of the United States, crossing three lower Northeastern United States, Northeast states (New York, Pennsylvani ...

and more than 50 times the flow of the

Rio Grande The Rio Grande ( or ) in the United States or the Río Bravo (del Norte) in Mexico (), also known as Tó Ba'áadi in Navajo language, Navajo, is one of the principal rivers (along with the Colorado River) in the Southwestern United States a ...

. The Gila project aqueduct branches off towards

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

while the All-American canal branches southwards for 37 miles (60 km) before reaching its headworks on the

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

border and bends west towards the

Imperial Valley The Imperial Valley ( or ''Valle Imperial'') of Southern California lies in Imperial and Riverside counties, with an urban area centered on the city of El Centro. The Valley is bordered by the Colorado River to the east and, in part, the S ...

References

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External links

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USBR website

IID website

From the Colorado River to the Salton Sea: The story of Imperial Valley's Water (slideshow)
{{Authority control Dams in Arizona Dams in California Dams of the Lower Colorado River Valley Buildings and structures in Imperial County, California Buildings and structures in Yuma County, Arizona United States Bureau of Reclamation dams Dams completed in 1938 Dams on the Colorado River