Imperiled Grand Canyon is facing a great dilemma

GRAND CANYON NATIONAL PARK, Ariz. — It's hard to get the sense anything is wrong in the Grand Canyon while floating through it.

On a recent spring morning, the Colorado River was cool and calm. Trout leapt, splashing back into the river with a plop. Stands of salt cedar lined the banks, offering shade from the desert heat.

But all is not well in this crown jewel of America's national park system.

The salt cedar and trout are invaders, part of a wave of alien fish and plants that have moved in and devoured or crowded out the native species. The sandy shorelines are washing away. And once-buried Indian archaeological sites are slipping into the river.

The Grand Canyon is in deep trouble, and the government-appointed panel assigned to come up with solutions is torn by competing interests and cannot muster the political will to act decisively.

"The best that we can do is keep slapping on as many Band-Aids as we can and hope the patient survives," complained Pam Hyde, one of two environmentalists on the panel.

The Colorado is a different river from one explored by the one-armed Civil War veteran John Wesley Powell, who in 1869 led the first expedition through the Grand Canyon. The landscape and biology have been transformed by the Glen Canyon Dam, built upstream in 1963 to generate hydroelectric power and store water.

Before the dam was erected, the Colorado would fill with snowmelt and flood violently in the early summer, then dwindle to a trickle in the winter. The dam smoothed out the flow.

In Powell's day, the Colorado was warm and muddy. Now it runs cold and clear, because sediment gets caught behind the dam in Lake Powell and because the water released through the dam comes from the reservoir's lower, cooler depths.

Over the years, nearly $200 million has been spent assessing what the dam has done to Grand Canyon and exploring what can be done to fix it.

In an ambitious experiment to see whether Glen Canyon Dam can help solve the very problems it created, the U.S. Geological Survey has unleashed floods, released pulses of water and even simulated a summer drought to see if this would build up the sandbars and restore the river in other respects.

Also, lasers and sonar map the canyon's loss of sand. Implanted microchips allow scientists to monitor endangered fish and follow the movements of boulders downstream.