Glen Canyon Dam - Restoration Efforts

Restoration Efforts

On March 26, 1996, the penstocks and two of the outlet works' bypass tubes at Glen Canyon Dam were opened to maximum capacity, producing a flood crest of about 45,000 cubic feet per second (1,300 m3/s) on the Colorado River. This was not due to any flood or mechanical failure, but rather was a controlled effort to assist the recovery of the damaged riverine ecosystem by mimicking the spring freshets that once swept through the canyons yearly. The flow appeared to have scoured clean numerous pockets of encroaching vegetation, carried away rockslides that had become dangerous to boaters, and rearranged sand and gravel bars along the river, and was considered an environmental success.

Contrary to the initial results, the following years revealed that the offensive vegetation had not been carried away as previously thought – only buried, and had mostly recovered within six months. The surface area of sandbars had been increased, but much of the material had been eroded from the submerged portions of the bars and deposited on top, making them unstable, rather than scoured from the riverbed as hoped. Reclamation has repeated the floods periodically, another time in 2004, 2008, and again in 2012.

Nevertheless, some continue to believe that the dam has too large and severe of an effect on the river's ecology to make restoration efforts worthwhile.