The federal operators of Glen Canyon Dam are conducting another “high-flow experiment,” turning loose massive volumes of water from Lake Powell in order to recharge the ecosystem downstream, including within the Grand Canyon.
By creating flood-like conditions on the Colorado River between Powell and Lake Mead, native habitat is scoured and restored. The high water charge has been proven in previous experiments to build sandbars in Grand Canyon, an important part of the native habitat.
The duration of the peak release of approximately 37,500 cubic-feet-per-second (CFS) will be 96 hours. It began on Monday. The power plant capacity for the seven generators within Glen Canyon is 22,500 CFS, which means that the dam’s four outlet tubes will be spraying 15,000 CFS, a spectacular sight.
Although the surface elevation of Powell will drop about two-and-a-half feet during the five day experiment, the water is part of the allotment that would be sent to Lake Mead and the lower basin states in any event.
In a press release, the Bureau said the science-based protocol is intended to improve understanding of how to better distribute limited sediment resources on the Colorado River between the two massive reservoirs.
“Dams have impacts, but as we have learned over the last 50 years, we can operate Glen Canyon Dam in ways that both meet our demands for water and hydropower, but also achieve our goals for natural resources and recreation,” said Deputy Commissioner for Operations Lowell Pimley.
Both Lake Mead and Lake Powell have been stressed by drought conditions since 2000, although Powell rebounded to about 50 percent of normal capacity thanks to an abundant water year on the Upper Colorado River that ended Oct. 1.
The high-flow experiments are scheduled to continue through 2020.