Or, according to river advocates, the plan that will govern use and allocation through 2026 could be a way to ensure none of the seven Western states that share the river ever has enough water.
The study's conclusions drew from a consensus decision by the seven Western states that depend on the Colorado River on what to do during low-water years, officials said.
"This is an arrangement for operating the river where everyone shares the pain when you're going through a drought time," said Tom Ryan, a Bureau of Reclamation hydrologist in Salt Lake City.
The Bureau of Reclamation began the environmental study in 1999. Since then, the river basin has experienced the worst drought in 100 years of recorded history, and its two largest reservoirs - Lake Powell and Lake Mead - have gone from being nearly full to just over half-full.
The report, expected to be final in December, plans how the upper basin states - Utah, Colorado, Wyoming and New Mexico - will respond to demand from California, Arizona and Nevada, the lower basin states, which have more people and older water rights.
While the Bureau of Reclamation implicitly acknowledges that the 1922 Colorado River Compact is based on estimates from unusually wet years and its report assumes ongoing shortages, it doesn't suggest any changes to the agreement.
"Nobody wants to renegotiate the compact. The feeling is the compact provides an adequate framework for managing the river," Ryan said.
But to John Weisheit, conservation director for the non-profit organization Living Rivers, the bureau's solution entrenches wastefulness and refuses to acknowledge ways to store water more effectively.
"We're extremely disappointed," he said. "Now we're playing this balancing act between two reservoirs that climate change is going to keep empty."
Living Rivers has long campaigned to decommission the Glen Canyon dam and rely on Lake Mead for surface water storage. The organization also believes using aquifers in Arizona and California to store water underground would be a better solution. But the main problem with the bureau's solution is there's not enough water, which speeds destruction of the river ecosystem, Weisheit said.