Gawkers flock to see dam's water release

Glen Canyon test aimed at reviving downstream habitat

By Jerd Smith, Rocky Mountain News

Wednesday, March 5, 2008

Two scientists from the U.S. Geological Survey prepare for the release Tuesday night of some 202,000 acre-feet of water through Glen Canyon Dam designed to mimic historic spring snowmelts.

Photos by Chris Schneider / The Rocky

A boat floats Tuesday next to the jet tubes at the Glen Canyon Dam in Arizona. Those tubes will be open for 60 hours through Friday, flooding the Grand Canyon to improve fish habitat.

Hundreds of people drove across the northern Arizona desert this week, intent on reaching Glen Canyon Dam for today's torrential release of water, designed to mimic spring snowmelts from the days when the mighty Colorado River roared unimpeded through the Southwest.

Motels in the tiny town of Page, perched just above the dam, were sold out Tuesday night, as scientists, environmentalists and federal water managers flocked to witness and record the rare event.

"It's a gigantic deal," said Mike Gauldin, a spokesman for the U.S. Geological Survey. "The Grand Canyon is a world-class phenomenon that people all over the world are interested in."

This is just the third time in the dam's history that such a man-induced flood has been conducted.

The grand experiment is not without cost, however. Western states that rely on the electricity generated from the dam, including Colorado, will have to find extra power, roughly 9 percent, elsewhere because less electricity will be generated during the 60-hour release.

Colorado, Utah and Wyoming also will see less of their Colorado River water stored in Lake Powell, where they prefer it be kept. Instead, it will reside in Lake Mead, farther downstream.

U.S. Bureau of Reclamation technicians began opening the dam's giant valves at 10 p.m. Tuesday, aiming to reach peak flows roughly 12 hours later, when U.S. Secretary of the Interior Dick Kempthorne arrives to preside over the experiment.

Through Friday, the river will flood, carrying four times the amount of water it normally does, rising from flows of 10,000 cubic feet per second to more than 41,000 cf/s, according to Larry Walkoviak, regional director of the reclamation bureau's Upper Colorado Region.

All told, more than 200,000 acre-feet of water, will be released this week, roughly the amount metro Denver uses in a year.

Nearly 100 scientists are here to monitor sediment movement and track dozens of trout that have been fitted with special transponders.

Because the trout aren't endangered, "we can experiment with them a bit," Gauldin said. The river's endangered species, the humpback chub, is so fragile that any experimental work is considered risky.

It is, after all, the habitat of this ancient fish that the scientists are trying to improve with these high flows.

Glen Canyon Dam, like other large federal water projects, traps large amounts of sediment, leaving the river between Lake Powell and Lake Mead, with little left over for the coves and beaches the chub need to flourish.

The experimental flows will help redistribute the sediment.

And that likely will improve the habitat of the kayakers, rafters and campers who visit the Grand Canyon each year, something everyone considers a political plus for the fractious Colorado River.

Even so, a lot of water is being moved many miles downstream. And how much water is stored where and when is a touchy topic among water managers, although the experiment doesn't mean anyone gets less.

It just changes the timing of deliveries on the tightly regulated river.

For the moment, drought worries have waned. This year is shaping up to be the best year in a decade, thanks to deep snowpacks in the Colorado Rockies. Flows into Lake Powell are expected to hit 120 percent of average.

Still water managers are wary.

"It means there is less water in our savings account," says Chris Treese, a spokesman for the Colorado River Water Conservation District in Glenwood Springs. "But as long as I'm shoveling snow every day, I worry less and less."

smithj@RockyMountainNews.com or 303-954-5474

River flood coverage

Tuesday: Large-scale experiments at federal water projects in which dams are operated to produce spring floods and to alter flows are becoming more common in the West.

Wednesday: Doing anything on the fractious Colorado River - from moving water to generating hydropower to protecting fish - is never easy. In massive experiments such as the Glen Canyon flood, water managers worry over their carefully saved water, even as they open the floodgates.

Thursday: A day on the life of the roaring Colorado River. Campers, rafters, scientists and locals watch the floodwaters rise.