Fifty years after the first explosive blast signaled the beginning of construction on Glen Canyon Dam and its mission to store and manage millions of gallons of water from the Colorado River, critics of the massive federal project are calling for its demise while other experts say it's vital to the West's water-storage system.

"Glen Canyon Dam is a boondoggle," said Richard Ingebretsen, president of the Glen Canyon Institute in Salt Lake City. "It has wreaked havoc on the ecosystem of a beautiful river. Of all the dams that are useless, this place, Glen Canyon Dam, is the worst."

On Thursday, the Bureau of Reclamation will host a 50th anniversary celebration of the Colorado River Storage Act of 1956 at Glen Canyon Dam. The act also authorized the construction of Flaming Gorge Dam. Mark Limbaugh, assistant secretary of water and science for the Department of the Interior, is scheduled to speak at the invitation-only event.

Dennis Strong, director of the Utah Department of Water Resources, said Glen Canyon Dam is fulfilling its purpose, not only as a critical piece of the West's vast water storage program but in its role as a hydroelectric power plant producing electricity for nearly 6 million customers.

"There will always be a conflict between those who think we should let water run down the river and those who think we should manage it as a resource," Strong said. "Glen Canyon Dam and Lake Powell have functioned exactly as they were designed to do. They have allowed the upper Colorado basin states to deliver water to the lower basin states and fulfill their contract."

In 1956, Congress passed the Colorado River Storage Project Act, or CRSP, which authorized the initial construction of four large dams and reservoirs, including Glen Canyon Dam and Flaming Gorge Dam on the Green River tributary, to help tame and store 34-million acre-feet of water from the turbulent Colorado River.

Seven states — Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming — and Mexico all claim various complicated legal water rights in the Colorado River.

At the time of its passage, the act generated controversy because of its massive scope. Environmentalists argued the giant reservoirs would waste water through evaporation and seepage, and that the salt content in the water would rise. Sediment that normally flowed unimpeded down the Colorado River, they argued, would eventually clog the system and ruin the comprehensive system of dams, reservoirs, spillways and other measures taken along the length of the river.