Imperial Dam and All-American Canal Project - CA

State:: CA
Site Type:: Infrastructure and Utilities, Water Supply, Flood and Erosion Control, Dams
New Deal Agencies:: Bureau of Reclamation (BuRec), Conservation and Public Lands, Public Works Funding, Work Relief Programs, Public Works Administration (PWA), Works Progress Administration (WPA)
Designer:: John L. Savage - Canal Chief Designing Engineer

Description

Imperial Dam was built by the Bureau of Reclamation during the New Deal as a feature of the Boulder Canyon Project, along with Hoover Dam and Parker Dam, on the lower Colorado River. It lies 17 miles above Yuma, Arizona. It is the diversion structure for the All-American Canal, which serves the Imperial Valley and Coachella Valley in Southern California and for the Gila Project in Arizona.

The dam is 3500 feet along the crest and 41 feet high at overflow point. The All American Canal headworks has a maximum diversion capacity of 15,000 cfs. The length of the All American canal – so-named because it did not go through Mexico – is 81 miles. The main water contractor is the Imperial Irrigation District in Imperial County, CA, which takes the largest percentage of Colorado River water of any user on the river system.

“The recently completed Imperial Dam and desilting works, a unit of the All-American Canal project, is approximately 250 miles downstream from the Boulder Dam on the Colorado River. The primary purpose for the dam is the diversion of approximately three-fourths of the water released from the Boulder Dam into the new All-American Canal. At the head of the canal are a series of massive concrete gate towers, between which are the steel roller gates illustrated on this page.

The roller gates are mechanically operated from the towers to permit the passage of water which is not to be diverted into the canal, so that it may be used for irrigation purposes downstream in the vicinity of Yuma, Arizona. The operating towers are connected by an overhead bridge extending the length of the dam.

The All-American Canal is 200 feet wide with a water depth of 21 feet. It will be used to convey water a distance of 100 miles to irrigate approximately 1,000,000 acres of land in the Imperial and Coachella Valleys. At some points the channel cut will be 100 feet deep. Several power drops are being installed on the canal as there is a difference of level between the head and the Imperial Valley of 450 feet.

The estimate of cost of the project is 35,000,000 of which $10,000,000 was allotted by the W.P.A. The Imperial Dam and desilting works were designed in the Denver office of the Bureau of Reclamation and were completed in July 1938.”
(Short and Brown)

Source notes

Short, C. W. and R. Stanley-Brown (1939) Public Buildings: Architecture Under the Public Works Administration, 1933 to 1939. United States Government Printing Office: Washington, DC.