Nevada is expected to give up more than a quarter of its allocated Colorado River water — 84,000 acre-feet — over the next two years under a federal operating framework plan that cuts distributions to three states and is expected to be officially released this week.

Nevada holds by far the smallest share of the Colorado River of any of the three Lower Basin states — just 300,000 acre-feet, compared with Arizona's 2.8 million and California's 4.4 million. And it uses less than it is allocated — only about 212,000 acre-feet of its allocation in 2024, according to the Southern Nevada Water Authority (SNWA), recycling the vast majority of its water and sending it back to Lake Mead for credit. 

That restraint hasn't been enough to escape the reckoning. 

Nearly a quarter century of drought, worsened by hotter and drier conditions tied to climate change, has pushed combined stored water in Lake Mead and Lake Powell, the two reservoirs central to the Colorado River system, to its lowest point since 1957.

The temporary rules written in 2007 and expanded in 2019 to manage that decline expire in October. The final environmental impact statement just released by the Bureau of Reclamation is the federal government's answer to a question the states themselves couldn't agree on: Who gives up how much water, and when.

Reclamation is expected to adopt the Lower Basin states' own short-term proposal, cutting Arizona, California and Nevada's combined water use by 3.2 million acre-feet through 2028 — a 21 percent reduction overall. Nevada is set to cut its use by about 28 percent, Arizona by about 31 percent and California by about 12 percent, according to officials who spoke to the Los Angeles Times and Reuters. 

Those cuts could nearly double after 2028, climbing to as much as 3 million acre-feet a year through 2036, if reservoir levels keep falling.

SNWA declined to discuss the reported numbers, stating it won't comment until the federal government releases the plan.

"The cut is the type of thing that we can endure quite well," said Kyle Roerink, a senior adviser with the Great Basin Water Network, a Nevada based water advocacy and conservation group. "It's what SNWA has been preparing for, what the Legislature has been preparing for. It's not really something that is going to upend the status quo in the immediate future."

What Nevadans will notice, he said, is pressure rather than shortage: a continued ask from regulators and public officials to respect what scarcity means, including watering restrictions understood "not as something that impedes your life in your community, but as a shared sacrifice for the greater good." 

The bigger risk is what happens if the snowpack doesn't recover. 

"We're one or two bad winters away from getting to really, really scary territory," Roerink said. "What we need to be doing right now is our snow dances more than anything else." 

Elizabeth Koebele, a UNR political science professor who studies Colorado River governance, said the state's ability to build back a cushion is worrying.

"Our runoff and our hydrology is so bad this year that we're probably not going to be able to rebuild our reservoir storage very much, if at all, to help us weather future challenges," she said. "These kinds of water supply stressors aren't going away."

How Nevada got here

The 1922 Colorado River Compact dividing the river's water was written during an unusually wet stretch of years — some of the wettest in more than 1,000 years, water law scholar Robert Glennon told Colorado public radio station KUNC — so the negotiators split up more water than the river has reliably produced ever since. 

Nevada came away from that deal with a small piece of an already overpromised river, but the state's dependence on it has only grown: Colorado River water now makes up nearly 90 percent of the supply for the Las Vegas area's 2.3 million residents and more than 40 million tourists who visit each year.

Since 2002, SNWA has spent more than $300 million in conservation programs, cutting the region's consumptive use of Colorado River water by more than 115,000 acre-feet a year even as the area's population grew by nearly 800,000 people. An acre-foot is the amount of water needed to cover an acre of land a foot deep — about 326,000 gallons, or enough to supply roughly two to three households for a year — and it's the standard unit water managers use.

Lake Mead is the reservoir that the authority actually draws its water from, while Lake Powell functions mainly as upstream storage. But a group of Colorado River researchers has argued the two reservoirs should be evaluated as a single system, because water moves between them and each affects how the other operates. Researchers predict that water levels will likely keep declining to record lows until next spring's snowmelt arrives and argue that deeper and more permanent cuts to water use are needed to stabilize the system.

Beyond drinking water, both reservoirs also generate hydropower relied on across the Southwest. If water levels fall far enough, they drop below the intakes that feed each dam's turbines, and hydropower generation stops entirely.

Arizona, California and Nevada argue they've already absorbed years of cuts and that the Upper Basin states — Colorado, Utah, Wyoming and New Mexico — need to start sharing the burden. Those states counter that they're the ones absorbing climate change's impact directly and that their water users face involuntary reductions each year because of the lack of physical and legal availability of water.  

What's at stake for Nevada

Strip away the interstate posturing, and the dispute centers on what water managers call the Lower Basin's "structural deficit" — the gap between how much water the Lower Basin states use each year and how much the river naturally supplies, even in years that aren't especially dry. Closing that gap, or at least not widening it, is the reason for the new rules.

The Upper Basin states have pushed back with a different theory of the problem. In their view, climate change, not their own water use, is why less water reaches the Lower Basin, and they shouldn't be penalized for hydrology they didn't create. Their proposal would tie operations to actual, observed water supply each October rather than long-range forecasts, and rejects any mandatory Upper Basin cuts.

Roerink said the river's priority system is what gives the Lower Basin its footing in that fight. 

"It is first in time, first in right," he said, noting that the Upper Basin states are "crying foul constantly about use in the Lower Basin." The oldest rights on the river — in Yuma, Arizona, in Imperial County, California, and a couple in Nevada — date to a period when far more water was being developed downstream than upstream, which he called "the saving grace" for Lower Basin users under existing law.

Roerink said Nevada benefits from having nearly all its water run through a single agency, unlike Arizona, where the Central Arizona Project, municipalities, farms and tribes all hold separate rights. That, he said, "simplifies things and streamlines overall management."

Nevada also built a backstop other states lack. In 2015, the water authority finished a project known as the third straw — a 3-mile tunnel drilled through bedrock beneath Lake Mead, ending in a new intake that draws water from its deepest point. The tunnel means Las Vegas can keep pulling water even if the reservoir drops far below the level at which the older intakes would stop working. 

What's next

Arizona Gov. Katie Hobbs has called cuts to the state's allocation "unacceptable," and won't accept a plan that puts all the burden on the three Lower Basin states. On the other side, Utah's top water negotiator, Amy Haas, has argued it would be "folly" for states to pursue litigation instead of managing the river system themselves.

Multiple state officials have floated challenging federal authority in court rather than accept either outcome.

Several states have set aside money to hire legal teams, but most policymakers know litigation is expensive and slow. There is currently one Supreme Court justice from west of the Mississippi and none from the Colorado River Basin, UNR's Koebele noted, and handing water decisions to the Supreme Court "would be a really big shift in the trajectory of Colorado River governance."

Rather than locking in a long-term framework, Interior has signaled it will pursue a 10-year approach, with the underlying operating rules reviewed and adjusted every two years — a shift from earlier plans for a longer, roughly 20-year interim period. That gives federal officials room to adapt as conditions change, but it also means Nevada water users may face a moving target rather than a settled set of rules for the next decade.

Reclamation is expected to issue the final plan this week.