Six of the seven basin states sketched out a joint proposal for how they could meet the federal government's demand to limit water consumption as more than two decades of drought have already pushed the crucial reservoirs to dangerously low levels. California, the largest water user of the seven basin states, did not join.

According to reports, the Department of the Interior had asked all seven states to contribute plans by the end of last month to reduce water usage by two to four million acre-feet or up to one-third of the river's annual average flow.

The proposal by the six states – Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming – aims to protect the major reservoirs in Lake Powell and Lake Mead from falling below critical levels, such as when the dams would no longer be able to generate electricity, or at "dead pool," when water would effectively be blocked from flowing out of these lakes. Before above-average snows in recent weeks, the Bureau of Reclamation was projecting that Lake Powell could start to reach such thresholds by this summer.

"We recognize that over the past twenty-plus years there is simply far less water flowing into the Colorado River system than the amount that leaves it and that we have effectively run out of storage to deplete," the six states said in a letter to the bureau earlier in the week.

State representatives said they would continue to work together and with the federal government and others "to reach consensus on how best to share the burden of protecting the system from which we all derive so many benefits."