Marble Canyon Dam States Geological Survey, which designated sites for "an unbroken string of [hydroelectric] dams from the mountains of Colorado and Wyoming to the last canyons of the Colorado River along the California/Arizona border". Although the Bureau of Reclamation expressed interest at this time in developing hydroelectric generation at the Marble site, these plans were postponed in favor of building the Hoover Dam, which would provide a much greater storage capacity for irrigation and flood control. However, once Hoover was completed the Bureau once again set its sights on the Grand Canyon, which has the greatest hydroelectric potential of any canyon in
Course of the Colorado River is removed for irrigation here. The Gila Gravity Main Canal provides water for the Gila Valley in Arizona. The All-American Canal, which runs west to the Imperial Valley of California, is the largest irrigation canal in the world, capable of carrying – the entire natural flow of the Colorado prior to damming. The canal supplies more than half a million acres (2000 km) which due to its mild climate grows most of the winter produce in the United States. Below Imperial Dam the remnants of the Colorado river lessen in gradient and in its lower course flows through the Colorado