The US Bureau of Reclamation released a torrent of water from Glen Canyon Dam last month as a way to shore up the shoals and beaches along the Colorado River.
Thanks to the watchful eye of NASA's Landsat 8 and Landsat 9 satellites, we can now see just how much of a change the deluge brought to the river.
Following one of the West's wettest winters in years, the Bureau of Reclamation conducted what it calls a "High Flow Experiment" April 24-27 releasing up to 39,500 cubic feet of water per second from the prey for a period of 72 hours.
That is well above the dam's typical discharges, which range from 8,000 to 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 buildup along the stretch of river below Lake Powell's Glen Canyon Dam as which meanders through Horseshoe Bend and Marble Canyon.
"While there are small changes in the orientation of the shadows between the two images, most of the visible changes in the river are due to higher water levels associated with the high flow experiment," the expert said. the agency said in a press release.
Since construction of the Glen Canyon Dam was completed in 1963, the amount of sand flowing into the Grand Canyon has been reduced by more than 90 percent, according to the United States Geological Survey.
That sandfall has led to a significant reduction in the number and size of shoals in the Colorado River, areas that are frequented by campers and rafters and are considered important habitats for aquatic and bird species. High flow releases are intended to mimic natural flooding that would normally carry sediment downstream.
This year's high-flow experiment was the first conducted by the Bureau of Reclamation since 2018. Long-term drought that has resulted in hotter, drier weather in the Southwest and less water flowing into the Colorado River each year has forced federal water managers to prioritize keeping more water in Lake Powell.
US Geological and National Park Service staff will document changes in sediment along the river over the next few weeks.
Contact Colton Lochhead at clochhead@reviewjournal.com. Continue @ColtonLochhead On twitter.
