As reported in the New York Times last month, the Glen Canyon Dam below Lake Powell in Utah is under consideration for decommission, owing to inefficiencies stemming from lack of inflow, evaporative loss and underproduction of electrical generation. One of the more recent major dam installations to be completed in the Western US, the debate over the utility of Glen Canyon comes decades sooner than the originally envisioned life cycle of the project.
Debate has apparently been ongoing on at the agency policy level for some time. The Times published the following quote and summary:
"The Colorado River system is changing rapidly," said Daniel Beard, a former commissioner of the federal Bureau of Reclamation, which oversees the government's dams in the West. "We have a responsibility to reassess the fundamental precepts of how we have managed the river."
"In 1956 the Colorado River Storage Project Act paved the way for the construction of four large power-generating dams in the upper basin of the Colorado River — a project meant to match the dam development that the southern half of the river had already seen. The Bureau of Reclamation had zeroed in on a dam site on a tributary in northwestern Colorado called the Green River, where the resulting reservoir would have submerged a tract of treasured, fossil-laden parkland called Dinosaur National Monument. Environmentalists, led by David Brower, executive director of the Sierra Club, fought passionately to preserve the monument in one of the nation's epic conservation battles."
Brower himself expressed regret for not pursuing more opposition to Glen Canyon years later in Sierra Club magazine.
"Whatever the final details of Lake Powell's water losses turn out to be, the draining of the lake simply has to happen. The river and the regions dependent upon it, including Baja California and the Gulf of California, can no longer afford the unconscionable loss of water. We need to get rid immediately of the illusion that the only way to protect water rights is by wasting water in Lake Powell. We can simply let the flow reach Lee's Ferry, Arizona (the dividing point between the Upper and Lower basins), naturally, beautifully, and powered by gravity at no cost."
Dam removals such as on the Elwah in Washington state are proving to restore historical populations of migratory specie like wild salmon and steelhead, a positive for fly fisherman. However, tailwaters below dams create excellent habitat and angling resource for landlocked specie of trout as well. Outside of the immediate and probably negative impacts on Lee's Ferry -- a major western tailwater trout fishery and major tourism resource for the town of Page, AZ -- the article references other unspecified potential sites for development in the Colorado basin should Glen Canyon be shut down. The Lake Mead vs. Lake Powell debate notwithstanding, these locations aren't likely going to be downstream of current impoundments.