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
Risks to the Glen Canyon Dam Dam forming Lake Havasu, Palo Verde Dam, and other dams and reservoirs. Because Glen Canyon Dam is also the central element of the Colorado River Storage Project, a failure may, depending on the volumes of water released and the damage caused, limit or completely cut off water supply to residences or farmlands along the Colorado River, and even into southern California depending on damage to canal headworks. The failure of Glen Canyon Dam would also destroy up to 964 known archaeological sites, including 264 that it currently affects in the Grand Canyon. Risks to the Glen Canyon Dam Glen Canyon