ENVIRONMENT / GLEN CANYON DAM : Colorado River: Electricity vs. Natural Wonder : Critics claim rapid changes in the water level to meet power needs have harmed the region. The Interior Department is evaluating the impact on the area.

Twenty-seven years after it built the 710-foot Glen Canyon Dam near the Arizona-Utah border, the federal government is preparing to weigh major changes in the huge project’s operations.

Under pressure from environmentalist lawsuits, the Department of the Interior recently concluded eight regional hearings to help it frame an environmental impact study, which is expected to last until next year.

Jammed in 1963 into the straight, red Navajo sandstone walls at the narrowest point of the Colorado River gorge, the dam changed the warm, muddy and wild Colorado to a cold, clear, managed river. The benefits were immediate: flood control, water distribution, creation of massive amounts of hydroelectric power.

But over the years, the operation of the dam meant big changes to the floor of the Grand Canyon downstream. Often the river level would rise and fall 13 feet in a 24-hour period as the dam’s manager, the Western Area Power Administration, responded to requests for additional electric power. The huge swings eroded beaches and threatened native fish.

The government “might as well be running hundreds of bulldozers down the canyon floor daily,” said Rep. George Miller, (D-Martinez).

“The operation of Glen Canyon Dam is obviously an ecological and cultural disaster of epic proportions,” said Jon Parsons, a river guide and unsuccessful congressional candidate who appeared at one of the hearings in Flagstaff, Ariz. “There is only one alternative, only one true choice. To protect at all costs the greatest natural symbol the world has ever known.”

Meanwhile, utility companies say modifications in water releases from the dam could affect the availability of power during peak demand times and raise the prices they and their customers may have to pay for dirtier, alternative sources, such as coal or nuclear plants.

“You’ve got to understand why the dam was built to begin with,” said Cliff Barrett, director of the Colorado River Energy Distributors Assn., a group of 155 publicly owned utilities. “To provide a sure water supply for the upper basin development in the four upper basin states, and to provide a cash register to pay for all of that.”

Still, those concerned primarily about the Grand Canyon wasted no time at the hearings to vent their fury at the Interior Department.

“Historically, the bureau has operated the dam for the maximum peaking power, and downstream resources be damned,” said Edward Norton, president of the Grand Canyon Trust. Miller and 32 co-sponsors introduced a bill April 4 to direct Interior Secretary Manuel Lujan Jr. to set up interim operating criteria for the dam while the environmental impact statement is under way.

“While that EIS drags on for at least the next two years, the damage to the Grand Canyon will continue,” Miller told his colleagues.

The bill has drawn the praise and support of environmentalists, as expected, but so far has failed to attract the support of the Arizona congressional delegation or the region’s politically connected power companies.