In the early 1960s, anyone who opposed what the U.S. Bureau of Reclamation attempted to do was labeled by bureau commissioner Floyd Dominy as a "David Brower type."

It was not meant as a compliment.Brower, then-director of the Sierra Club and founder of Friends of the Earth, and Dominy - whom Brower sometimes referred to as a member of the "hydro-mafia" - were bitter adversaries during the 1950s and '60s, when the bureau embarked on the biggest dam-building binge in history.

That time would shape the environment-vs.-development debate for decades to come. And no two names were bigger during that time than Dominy and Brower.

Both in their 80s now, the men have mellowed in their mutual animosity but not in their beliefs - particularly on the biggest environmental controversy of all: Glen Canyon Dam on the Colorado River.

Dominy and Brower were in Salt Lake City this week to debate whether the dam and Lake Powell, the reservoir it created, were a good idea. (In between arguments, they sparred playfully over each other's progeny as well as their tastes in liquor and women.)

Dubbed "The Jewel of the Colorado" by the bureau and "The World's Biggest Septic Tank" by conservationists, Lake Powell continues to spawn heated passions on both sides. The pro-dam side maintains that 19th century explorer John Wesley Powell would be happy to have his name attached to the project. Detractors say Powell would pitch a fit.

Of all the dam's proponents, none is more boastful than Dominy.

"I'm proud that I'm known as the builder of Glen Canyon Dam and the creator of Lake Powell," says an unabashed Dominy. "I'm very proud of the fact that the 10 most-visited recreation areas behind dams have more visitation than the 10 most visited national parks."

Brower, twice nominated for the Nobel Peace Prize, has a different story.

"I was deeply saddened by the dam because (Glen Canyon) was one of the most beautiful places I'd ever seen in my life or ever would see," said Brower.

Indeed, Glen Canyon was once considered for national-park status during the Franklin D. Roosevelt administration, but the conservation movement was not organized well enough at the time to see it through.

When the bureau began carrying out its congressional mandate to deliver water to the Colorado River Basin states, it decided that Glen Canyon Dam was necessary to store water to ensure that the upper basin states could deliver the lower basin states' share of water (7.5 million acre-feet annually) during drought years.

Unlike Dominy, Brower believes the dam was not necessary for that charge, arguing that the 7.5 million acre-feet could have been stored in Lake Mead. With a capacity of 26 million acre-feet, Glen Canyon dam was "overengineered," said Brower, who advocates leaving the dam in place but emptying the reservoir until it is truly needed.

Water, however, is not the only benefit to the dam, says Dominy. It also provides electricity and recreation to millions of people who might not otherwise see the area.

Brower says the costs outweight the benefits on both points. Recreation is reliant on motor boats and is affordable only to the rich, whereas the pre-dam canyon was open to anyone who could hike or go down the river on a raft. And the true cost of the energy should take into account the cost of the reservoir's eventual closure, which will be forced when the reservoir fills up with sedimentation.

But the two antagonists can't even agree on when that closure will occur. Brower estimates complete sedimentation in 300 years; Dominy says it will occur no sooner than 1,000 years.

What should be done when it finally fills up?

"I'll let the people 1,000 years from now worry about that," said Dominy.

Brower said that kind of attitude is precisely why the world is suffering an environmental crisis now.