State and federal authorities say years of over-depletion are at odds with the harsh realities of climate change, pushing Colorado River reservoirs to dangerously low levels that the large dams on the river could soon become a barrier to delivering water to millions in the South West.
The federal government has asked the seven Western states that rely on Colorado River water to reduce use by 2 to 4 million acre-feet – up to a third of the river’s average annual flow – to try to avoid such dire results. . But the states have so far failed to reach a voluntary agreement on how to achieve that, and the Interior Department may impose unilateral cuts in the coming months.
“Without immediate and decisive actions, elevations at Lake Powell and Mead could force the system to stop functioning,” Tommy Beaudreau, deputy secretary of the Department of the Interior, said at a conference of Colorado River officials here Monday Friday. “That is an unacceptable condition that we will not allow to happen.”
Many state water officials fear they are already running out of time.
Ted Cooke, general manager of the Central Arizona Project, which delivers Colorado River water to central Arizona, said “there is a real possibility of an effective dead pool” within the next two years. That means water levels could drop so far that the Glen Canyon and Hoover dams – which created the reservoirs at Lake Powell and Lake Mead – would become a barrier to delivering water to cities and farms in Arizona, California and Mexico.
“We may not be able to get water past either of the two dams in the large reservoirs for certain parts of the year,” Cooke said. “This is on our doorstep.”
The impending crisis has energized this annual gathering of water bureaucrats, the occasional cowboy hat appearing among the standing-room-only crowd inside Caesars Palace. It’s the first time the conference has sold out, organizers said, and the massive shortage is emerging as state, tribal and federal water managers come together to hash out how to reduce usage on an unprecedented scale.
“I can feel the anxiety and uncertainty in this room and in the basin,” said Camille Calimlim Touton, commissioner of the Bureau of Reclamation.
Ultimately the negotiations will have to weigh cuts in fast-growing urban areas against the farming communities that produce much of the country’s winter vegetable supply. In the complex world of water rights, farms often have priority over cities because they have been using river water for longer. Unlike previous negotiations, water managers now expect cuts to affect even the most senior water users.
The Upper Colorado River Basin states — Colorado, New Mexico, Utah and Wyoming — say it’s hard to say how much they can cut because they rely less on reservoir allocations and more on fluctuating river flows. The low-lying basin states – California, Arizona and Nevada – also consume much more water.
“In the Upper Basin, we can say we take 80 percent, and Mother Nature gives us 30,” said Gene Shawcroft, chairman of the Colorado River Authority in Utah. “Those are some of the challenges we’re struggling with.”
The federal government set an August deadline for the states to reach a voluntary agreement on cuts, but that deadline passed without an agreement. Some state officials here blame the Biden administration. When it became clear this summer that the federal government was not ready to impose unilateral cuts, the urgency for a deal evaporated, they said.
Now the Biden administration has launched a new environmental review to distribute Colorado River supplies in low-water situations. Water managers hope to have more clarity on what states can offer by the end of January. By summer, the federal government is expected to define its authority to impose unilateral cuts.
“Unfortunately, it’s a year later than we want,” Cooke said in an interview.
Across the West, drought has resulted in a record number of wells running dry in California, forced vast swathes of farmland to lie fallow and forced homeowners to limit with the amount of water they put on their lawn. This week, a major water supplier in Southern California declared a regional drought emergency and asked those areas that rely on Colorado River water to reduce their imported supplies.
The problems on the river have been building for years. Over the past two decades, during the region’s worst drought in centuries, Colorado’s watershed states have taken more water from the river than it has produced, draining the reservoirs that act as a buffer during hard times. The river’s average annual flow during that period was 13.4 million acre-feet — with users withdrawing an average of 15 million acre-feet a year, said James Prairie, research and modeling group chief at the Bureau of Reclamation .
In 1999, Lake Mead and Lake Powell, the nation’s two largest reservoirs, held 47.6 million acre-feet of water. That has dropped to about 13.1 million acre-feet, or 26 percent of their capacity. An acre-foot equals 326,000 gallons, or enough to cover an acre of land in a foot of water.
Federal officials have projected that as early as July, the level in Lake Powell could drop to the point where the hydroelectric plant inside the Glen Canyon Dam could no longer produce power, and then continue to fall so that it would be impossible to deliver the quantities. water that the South West states depend on. Water managers say such a “dead pool” is also possible on Lake Mead within two years.
“These reservoirs have served us for 23 years, but now we’re straining them,” Prairie said.
David Palumbo, deputy commissioner of operations for the Bureau of Reclamation, emphasized that the effects of climate change — a hotter and drier West, where the ground absorbs more runoff from mountain snow before it reaches reservoirs — means that the past is no longer useful. A guide to the future of the river. Even high snow years are now seeing low runoff, he said.
“That runoff efficiency is critical to be aware of and, frankly, to fear,” he said.
Water managers say most of the cuts are likely to fall in southern states including Arizona and California, where large farming regions consume large portions of the available supply. These states, which receive water after passing through Lake Mead and the Hoover Dam, also face the greatest risk if the reservoirs fall to dangerous levels, said John Entsminger, general manager of the Southern Nevada Water Authority.
“If you can’t get water through Hoover Dam, that’s the water supply for 25 million Americans,” he said.
