U.S. Bureau of Reclamation officials have issued a draft environmental assessment that proposes a decade-long series of experimental high-flow releases of the Colorado River from Glen Canyon Dam and through Grand Canyon National Park.
The draft comes more than a year since Interior Secretary Ken Salazar called for more high-flow releases and nearly three years since the last one was allowed by BuRec, which at times has been seen at odds with the National Park Service over these orchestrated flows.
While the Park Service desires the high flow "washes" that scour the river corridor through the Grand Canyon, BuRec, which manages the Glen Canyon Dam in large part for its hydropower generation, at times has been seen as opposing a regular series of releases that might mimic natural surges of the Colorado River that occurred before the dam went into service in 1963.
The draft EA examining a long-term protocol for the releases, one that would run from 2011 through 2020, came out last Thursday. (While the release states that public comment will be taken for 30 days, it also says "written comments may be provided to Reclamation through February 14, 2011," or five days shy of 30.)
What BuRec officials want to learn through the high-flow "experiments" is "whether and how sand conservation can be improved in the Colorado River corridor downstream of the dam."
The protocol will provide an adaptive management framework to learn how to better conserve the limited sand supply to the Colorado River below the dam, while ensuring that no significant impacts occur to other downstream resources affected by the high releases.
During a high flow experiment, the high volume of water released from the dam suspends sand stored in the river channel deposited by tributaries. A portion of that sand is re-deposited in the downstream river reaches as sandbars and beaches while another portion is transported downstream by river flows. These sand bars and beaches, and the associated near-shore habitats, are important components of the Colorado River ecosystem in addition to providing camping opportunities for river runners and hikers along the Colorado River within Grand Canyon National Park.
Among questions to be answered through these flows is whether they could help replenish sand bars and beaches throughout the canyon; benefit native fishes such as the humpback chub while making conditions worse for non-native fishes; what impacts they might have on recreation in the canyon, and; how would vegetation respond?
The current draft EA calls for releases of up to 45,000 cubic feet per second.
"The timing of high-flow releases would be March-April and October-November, and the magnitude may range from 31,500 cfs to 45,000 cfs, and the duration may range from one hour to 96 hours," the draft says.
At times the Park Service and BuRec have encountered friction over this issue. Indeed, the last time a high-flow release was scheduled, in March 2008, BuRec officials didn't bother to send their draft EA on that release to Grand Canyon officials until the day before comments were due.
You can view a copy of the EA at this site. A printed copy of the report is available at the Bureau of Reclamation Upper Colorado Regional Office, 125 South State Street, Room 7218, Salt Lake City, Utah 84138.
Written comments may be provided to BuRec through February 14, 2011 to the address above or via [email protected] . For more information, or to request a printed or CD-ROM copy of the EA, please contact Dennis Kubly at (801) 524-3715.
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Comments
My daughter, niece and I rode the float from the Glendale Dam a few years back until it became the rapids, had an amazing time. Now that the you are choosing to do high powered release of more water into the Colorado river; what will happen to the floats?
I found that to be an amazing way to enjoy the river, the canyon and the beauty of nature.
If you mean the Glen Canyon Dam near Page, there will be no change to the floats. The release is short, and does nothing more than change out the sand on the beach, although that close to the dam I am not sure what it does to the beaches, since there are no real sources (tributaries) to contribute additional sediments for the river bed to scour and deposit onto the beach. The next real source downstream is the Paria at Lee's Ferry and then a much larger source at the Little Colorado about 80 miles further down.
Just a private citizen, I have no affiliation with any agencies.
They have run the flush several times and has not proven anything exept there were less chubs after the flush than before. All it does is build sand bars for the few river runners as compared the lakes users.
The problem is the lower river water users want and use more water than their 8.23 MAF and the Colorado river has only flowed thar much a couple of times since 2000 they seem to think they should get more water. The Colo river compact was constructed on the highest water years in history and the river is not supplying that much but the want more, They have received their 8.23 every year but with Lake Meade dropping so much proves they are using more water than is available. When the water is gone our economy will crash in the southwest.
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