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
Bridge Canyon Dam reservoir stretching more than upstream, including along the border of Grand Canyon National Park. The dam would serve mainly for hydropower production in conjunction with several others further upstream including Marble Canyon Dam, on the Colorado, Green and other rivers. Due to its enormous potential for environmental destruction and the dwindling flows of the Colorado River, the project stalled in 1968 after years of public opposition. However, the location is considered one of the best remaining sites for a large dam in the western United States. Bridge Canyon Dam was first seriously considered in the mid-20th century as part of