The US Bureau of Reclamation released a torrent of water from Glen Canyon Dam last month to reinforce the sandbanks and beaches of the Colorado River.
Thanks to the watchful eyes of NASA’s Landsat 8 and Landsat 9 satellites, we can now see the flood-induced changes in the river.
After one of the warmest winters in recent years in the West, the Bureau of Reclamation conducted the “High Flow Experiment” on April 24–27, releasing 39,500 cubic feet of water per second from the dam. 72 hours.
This figure is much higher than the normal discharge from the dam, which is between 8,000 and 25,000 cubic feet per second.
Before-and-after photos released by NASA Earth Observatory show subtle but significant changes in the amount and location of sand build-up along the stretch of river below Lake Powell’s Glen Canyon Dam, by Horseshoe Bend and Marble Canyon.
“While there are small changes in the orientation of the shadows between the two images, most of the changes seen in the river are due to higher water levels associated with the higher flow experiment,” the agency said in a statement.
Since the completion of Glen Canyon Dam in 1963, the amount of sand flowing into the Grand Canyon has decreased by more than 90 percent, according to the US Geological Survey.
This reduction in sand has resulted in a significant reduction in the number and size of sandbanks along the Colorado River, areas frequented by campers and rafters and considered important habitats for aquatic species and birds. The purpose of the high flow discharge is to mimic a natural flood that would normally carry sediment downstream.
This year’s high flow experiment was the first conducted by the Office of Reclamation since 2018. Prolonged drought that results in hot, dry weather in the Southwest and less water flowing into the Colorado River each year has forced federal water managers to prioritize water conservation. More water in Lake Powell.
Staff from the US Geological Survey and the National Park Service will spend the coming weeks documenting changes in sediment along the river.