Flushing out the Grand Canyon: Floodgates open on experiment to shift 500 MILLION TONS of sand and silt trapped in Colorado River

The Colorado River flooded the Grand Canyon on Monday as part of an ongoing experiment to rebuild beaches and restore fish habitat in the iconic Arizona gorge.

Interior Secretary Ken Salazar was on hand to open the river outlet tubes at the Glen Canyon Dam in an attempt to clear out the hundreds of millions of tons of sediment that settled at the bottom of the river thanks to the massive concrete barrier.

Salazar called the experiment ‘an historic milestone’ and ‘a new era in which we realize that the goals of water storage, delivery and hydropower production are compatible with improving and protecting the resources of the Colorado River.’

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Gushers: Water rushes from the Glen Canyon Dam as part of an experiment aimed at building beaches and sandbars on the Colorado River through the Grand Canyon Artificial flood: The peak flow of 42,000 cubic feet per second lasted 24 hours, and the Colorado River will run high for five days



Matter of state: U.S. Interior Secretary Ken Salazar was on hand to open the valves Monday, calling the project 'an historic milestone'

The peak flow of 42,000 cubic feet per second lasted 24 hours from 9pm Monday until 10pm Tuesday, and the river will run high for five days, making it the fourth artificial flood in 16 years, according to Discovery News.

The heavy rush of water down the river at Glen Canyon Dam is part of a government program to restore the Grand Canyon's ecosystem.

The goal is to wash millions of tons of sediment downstream to create beaches and improve habitat for plants and animals, and protect archaeological sites.

Before the Glen Canyon Dam was completed in 1966, the Colorado River supplied more than 90 per cent of the sediment forming the canyon's beaches, popular among tourists and river rafters.

The dam has been trapping sediment, which ends up at the bottom of the canyon in the upper reaches of Lake Powell and is permanently blocked from moving downstream.

The goal of the high-energy flood is to unblock the roughly 500 million tons of silt and sand resting underwater below the dam, which is enough to fill a football field 230 feet deep, Desert News reported.



Massive barrier: Completed in 1966, the Glen Canyon Dam, at full pool, holds 26million acre feet of water

Early attempts: High-energy floods that took place in 1996, 2004 (pictured above) and 2008 were limited fact-finding experiments



Grand Canyon National Park officials have contacted visitors with backcountry or river permits and advised them to camp on high ground this week, according to The Arizona Republic.

The experiment that could hurt next year's fishing - and complicate hydropower production and water storage - in the name of a more environmentally correct river.

The rush of water churning up sand for new beaches and backwater sandbars was welcomed by many environmentalists and park managers. It's the fourth experimental high flood since 1996, and the first since Salazar in May decreed them routine in a 10-year protocol that, weather permitting, could mean mini-floods every year through 2020.

‘This is a great victory,’ said Nikolai Lash, program director with the Grand Canyon Trust.

Previous experiments in 1996, 2004 and 2008 were one-time fact-finding missions instead of fundamental shifts in river management.



VIDEO: 500 MILLION TONS of sand and silt released from Glen Canyon Dam

Mission: The goal of the experiment is to unblock the roughly 500 million tons of sediment resting underwater, which is enough to fill a football field 230 feet deep

Log-term plans: Government officials plan to flood the canyon on an annual basis, weather permitting, through 2020

Conservation: Organizers of the flood hope that the torrents of water will have rebuild beaches, restore the natural habitat of fish and preserve archeological sites



‘This (Obama) administration can be patted on the back and thanked for doing what we've been trying to do, seriously, for 15 years,’ Lash added.

The previous experiments yielded mixed results, partly because a return to up-and-down flows timed partly to regional summer hydropower needs wiped out many of the new beaches and sandbars.

Advocates hope the effects will be longer lasting if these floods come more regularly and if a longer-term Interior Department planning effort leads to steadier flows through the summers.

But critics say there's little environmental benefit and that it comes at a cost.

In comments submitted to the Interior Department before the decision to go forward with regular flushes, the Colorado River Energy Distributors Association, a group of non-profit energy utilities, noted that previous springtime flood experiments helped boost the population of non-native trout that feed on the endangered humpback chub.