Risks to the Glen Canyon Dam that the resulting flood would scour the bottom few hundred feet of the Grand Canyon, overtop Hoover Dam, and cause severe damage all along the lower Colorado River. In the event of a complete dam failure with Lake Powell at high pool, about of water would surge out of Lake Powell at an initial depth of over . Downstream communities and perhaps every dam along the river, excluding possibly Hoover Dam, as well as riverside lowlands, would be inundated or severely damaged. Located downstream from Glen Canyon Dam are Hoover Dam forming Lake Mead, Davis Dam forming Lake Mohave, Parker
Steamboats of the Colorado River the Colorado Steam Navigation Company between Yuma and Needles. By the end of 1905 all the steamboats, "Cochan", "St. Vallier" and "Searchlight", were withdrawn down river to Yuma. Their places were taken by smaller gasoline powered boats, until they were in turn replaced by trucks. The remaining steamboats worked on irrigation projects on the lower part of the river and on repairing the 1904-1907 breach in the Alamo Canal, that directed the Colorado River into the Salton Sink and created the Salton Sea before it was repaired. The last project, the construction of the Laguna Dam ended steam navigation on