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Colorado River: New study offers painful details of Glen Canyon Dam impacts to downstream ecosystems

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Glen Canyon Dam has fundamentally altered downstream ecosystems in the Colorado River. Photo courtesy U.S. Bureau of Reclamation.

‘A shadow of pre-dam conditions … ‘

By Summit Voice

FRISCO — With all the focus on water quantity in the Colorado River Basin, it’s easy to lose sight of the fact that the installation of massive dams has fundamentally altered the river’s ecosystem.

But an in-depth three-year study done as part of the Glen Canyon Dam Adaptive Management Program offers a stark reminder of the changes wrought by drastically altering the river’s hydrological regime. Continue reading

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Is the Colorado River tapped out?

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A NASA satellite image of the Colorado River and Lake Powell in Utah and Arizona.

Federal water agency says it will cut deliveries from Lake Powell next year

By Bob Berwyn

FRISCO — Colorado River water supplies are already stretched dangerously thin, and the faucet is about to get turned down, as federal water managers said they will probably have to curtail downstream deliveries from Lake Powell in 2014.

July inflow into Lake Powell was just 13 percent of average, following a spring runoff season during whic the river delivered only about a third of the average amount of water. Continue reading

Environment: A river restored?

Federal water managers simulate flooding flows in Colorado River

Bypass valves open to release a huge surge of water into the Colorado River below Glen Canyon Dam. Photo courtesy Bureau of Reclamation.

By Summit Voice

SUMMIT COUNTY — Water may be in short supply in the West this year, but that didn’t stop federal officials from cranking open the valves of Glen Canyon Dam to unleash what’s  unromantically being called a high-flow experimental release. The release won’t change the overall water balance in the Colorado River system, as adjustments are made at other times.

The five-day high-flow regime will lower Lake Powell by up to 2.5 feet in just a few days and send more than 42,000 acre feet of water surging through Glen, Marble and the Grand Canyon before it ends up Lake Mead. A detailed FAQ is online here.

This year’s release is the first since 2008 and is intended to rebuild depleted sandbars and beaches. Under the concept of high flow experimental releases, sand stored in the river channel is picked up by high-volume water releases from the dam and re-deposited in downstream reaches as sandbars and beaches. Continue reading

Water: Near-record inflows boost Lake Powell by 50 feet

2011 could turn out to be the second-best year ever for Lake Powell inflows

This Landsat 5 image from a NASA satellite shows Lake Powell on Aug. 6 2010. Click on the image to visit a NASA Earth Observatory website that documents the year-to-year changes in Lake Powell.

By Summit Voice

SUMMIT COUNTY — Flooding in the high country in early spring and summer may have been a nuisance for some, but in the big picture, it helped push Colorado River inflows into Lake Powell to near record levels. At times, Powell was rising at the rate of about 12 inches per day, bringing the water level up by 50 feet for the runoff season so far.

The Bureau of Reclamation reported that July inflow along totaled about 4.5 million acre feet (278 percent of average), the second-best year since Glen Canyon Dam was completed in 1963. Only 1995 was wetter, with a total inflow of 4.41 million acre feet in July. Total inflows for the runoff season, April through July, reached 12.9 million acre feet, which is 162 percent of average. June inflow was even higher, totaling 5.4 million acre feet. Continue reading

Report: Grand Canyon threatened by low flows

Environmental threats, Grand Canyon national Park

Low flows are one of the biggest threats to the ecological integrity of the Grand Canyon. NATIONAL PARK SERVICE PHOTO. Click on the image to visit the NPCA's Flickr photostream.

Conservation groups offer constructive suggestions for mitigating impacts to cherished global icon

*Read a related story on other threats here


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By Bob Berwyn

SUMMIT COUNTY — Grand Canyon National Park, an American and global icon, faces serious threats to its most important resources from uranium mining, air pollution and stream depletions, according to the National Parks Conservation Association.

The nonprofit, formed by Stephen Mather in 1916 as a citizen’s auxiliary to the National Park Service, released a new report Monday that identifies critical concerns and offers some strategies to address them.

“We’re trying to speak directly to the American people about how serious these threats are,” said David Nimkin, the organization’s Southwest regional director.

Nimkin said the Grand Canyon provides physical and spiritual recreation for millions of visitors, and also contributes more than $1 billion annually to the regional economy. Continue reading

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