A flood unleashed down the Colorado River through Grand Canyon National Park this week hopefully will rearrange roughly 500,000 metric tons of sediment, a moving project river runners are applauding.
Interior Secretary Ken Salzar, who opened the outlet tubes of the Glen Canyon Dam on Monday to start the flood, called the event historic, as the high-flow experiment would prove the "goals of water storage, delivery and hydropower production are compatible with improving and protecting the resources of the Colorado River.”
At the same time, George Wendt, president and CEO of OARS Outdoor Adventure River Specialists and a member of Protect the Flows, a coalition of nearly 600 businesses that operate along the Colorado River, said the five-day-long flood "will help to build new camping beaches in the Grand Canyon, and ultimately, will improve the canyon experience for boaters supporting a $26 billion recreation economy that depends on the Colorado River."
The flood is being counted on to mimic natural floods that used to flow in fall through the picturesque canyon and build and rebuild sand bars and beaches. When the high waters reach the mouth of the Paria River some 15 miles downstream of the dam, it's hoped they will push on down river for beach building some 500,000 metric tons of sand, silt, and other sediments, a deposit that in theory would "fill a football field 230 feet deep," according to Interior officials.
This release marks the first high-flow release through the Grand Canyon since 2008. Prior to that one, there was a similar release in 2004, and another in 1996. The difference this time around, is that officials are planning on a decade of year-after-year-after releases -- some years will have two releases, spring and fall.
"We applaud the Department of Interior for taking these important steps that take into consideration the long term use of the canyon by boaters. This release shows an attempt at good stewardship of the area and is an example of how the conservation community and those who love to recreate on the river worked together with the Department of Interior on a solution that both fish and rafters will benefit from for years to come," said Mr. Wendt in a prepared statement.
At Arizona Raft Adventures and Grand Canyon Discovery, another member of Protect the Flows, Alexandra Thevenin said, “Grand Canyon beaches are in a constant state of erosion, so replenishing the beaches is vital not only to Grand Canyon rafting, but more importantly to the Grand Canyon ecosystem as a whole, including promoting native vegetation and backwaters, which in turn supports many native species. We love it when the adaptive management works.”
The protocol identifies the conditions under which a high flow release will likely yield the greatest conservation and beneficial use of sediment deposited by inflows from Colorado River tributaries as a result of rainstorms, monsoons, and snowmelt.
“Favorable sediment conditions in the system only occur periodically, so the ability to respond quickly and make the best use of those deposits when the time is right is essential,” said Anne Castle, assistant secretary of the Interior for Water and Science. “Today’s experimental release under the new protocol represents a significant milestone in our collective ability to be nimble and responsive to on-the-ground conditions for the benefit of downstream resources.”
The high-flow releases are designed to simulate natural flood conditions that suspend and redeposit sand stored in the river channel to provide key wildlife habitat—including habitat for the endangered humpback chub, protect archaeological sites, enhance riparian vegetation, maintain or increase recreation opportunities, and improve the wilderness experience along the Colorado River in Glen and Grand canyons. Single experimental releases were conducted in 1996, 2004, and 2008, and included extensive scientific research, monitoring, and data collection by the U.S. Geological Survey’s Grand Canyon Monitoring and Research Center, the Bureau of Reclamation, the National Park Service, and the U.S Fish and Wildlife Service.
"These high-flow releases, a new paradigm in water management, recognize that there are hugely beneficial impacts to river ecology from releasing the requisite water needed downstream in large pulses, rather than uniformly throughout the year," said USGS Director Marcia McNutt. "In the arid West, non-uniform flow better mimics the natural environment in which the plants and animals flourished."