By Nick Cahill

When the Colorado River Compact was signed 100 years ago, the negotiators for seven Western states bet that the river they were dividing would have ample water to meet everyone’s needs – even those not seated around the table.

A century later, it’s clear the water they bet on is not there. More than two decades of drought, lake evaporation and overuse of water have nearly drained the river’s two anchor reservoirs, Lake Powell on the Arizona-Utah border and Lake Mead near Las Vegas. Climate change is rendering the basin drier, shrinking spring runoff that’s vital for river flows, farms, tribes and cities across the basin – and essential for refilling reservoirs.

The states that endorsed the Colorado River Compact in 1922 – and the tribes and nation of Mexico that were excluded from the table – are now straining to find, and perhaps more importantly accept, solutions on a river that may offer just half of the water that the Compact assumed would be available. And not only are solutions not coming easily, the relationships essential for compromise are getting more frayed.

With the Compact’s shortcomings and the effects of climate change and aridification becoming as clear as the bathtub ring around Lake Mead, previous assumptions of how much water the river can provide and the rules governing how it gets divvyed up must be revised to reflect the West’s new hydrology. One thing is certain among experts and Colorado River veterans: Water cuts are in the short-term and long-term forecast for major cities such as Los Angeles, Las Vegas and Phoenix, as well as farmers from Colorado’s West Slope to growers in California’s Imperial Valley near the Mexican border.

“You don’t have any other arrow in your quiver right now except to reduce use,” Pat Mulroy, former general manager of the Southern Nevada Water Authority, told a gathering of Colorado River water interests this fall. “There are no other arrows.”

The River’s Changing Math 

Predicting the amount of water the Colorado River can provide in a given year has always been a challenge. The river’s flow is famously erratic, dictated by the size of the often-fickle Rocky Mountain snowpack and other variables such as soil moisture and changes in temperature. 

The old expectations of the Compact signers is giving way to a new reality on the river. Over the last century, the river’s flows in the Upper Basin have dropped by 20 percent. Scientists have pinned warming temperatures as the main cause of the disappearing flows and predict the trend will worsen as the Upper Basin, source of most of the river’s water, becomes even hotter and drier. 

Water users have been able to counter previous dry spells by relying on the river’s main reservoirs. But after more than two decades of drought, both Lake Mead and Lake Powell are only about one-quarter full. The reservoirs’ rapid declines have forced the Bureau of Reclamation to order unprecedented water cuts to Arizona and Nevada. Mexico is taking similar cuts under binational agreements. And Reclamation has warned more severe actions are needed to prevent the collapse of the Colorado River system. 

The Compact signatories, relying on data from a small but abnormally wet time period, estimated the river’s annual average natural flow in the Upper Basin to be about 18 million acre-feet. The figure, they asserted, was enough to cover 7.5 million acre-feet of water in perpetuity for the Upper Basin states of Colorado, New Mexico, Utah and Wyoming, and 7.5 million acre-feet for the Lower Basin states of Arizona, Nevada and California. They also agreed that any water committed to Mexico would be supplied equally by the two Basins. Native American tribes, who now legally hold substantial rights to the river’s water, were barely mentioned.

Brad Udall, Colorado State University climate researcher, said it’s becoming harder and harder for the river to meet the promises outlined in the Compact and the accompanying set of agreements, laws and court cases referred to as the Law of the River. He warned dozens of water managers and policy experts at a recent Water Education Foundation Symposium that climate change caused by greenhouse gas emissions is rapidly and permanently shifting precipitation trends in the Basin.

“It’s not a drought, it’s not temporary, it’s aridification,” said Udall. “Additional 1 degree Celsius or more warming by 2050, Lee Ferry flows in 9 million acre-feet are possible. Every important trend line [is] heading in the wrong direction, notably our reservoirs, but all the science trends as well.”

Data from recent decades shows it’s becoming uncommon for the river to meet the benchmark used to craft the Compact. Estimated annual flows at Lee Ferry, a key dividing point between the Colorado River’s Upper and Lower Basins, have surpassed 18 million acre-feet just four times since 1991, while the river’s average flow since 2000 has been 12.3 million acre-feet.

“If we’re taking out more than comes in, it is really simple math that the reservoirs are going to continue to decline,” said Rebecca Mitchell, director of the Colorado Water Conservation Board, the state’s water management agency. 

Mitchell was among nearly 200 state and regional water managers, farmers, tribal leaders and other water interests from the seven Basin states, along with key federal and Mexican officials, who attended the Foundation’s biennial Colorado River Symposium in late September to mark the Compact’s 100th anniversary and to discuss the risks and challenges ahead for the iconic Southwestern river. 

Discussions were sometimes sobering and sometimes tense, underscoring the growing risks to a river depended upon for drinking water by 40 million people and for irrigation of more than 4 million farmland acres across the Basin. An undercurrent of the discussions was whether Basin interests can avoid taking their differences to court – a prime motivation behind creating the 1922 Compact. Despite the occasional sharply worded airing of differences between Upper and Lower Basin interests, there was broad acknowledgement that action is needed to keep the river system functioning. 

Reclamation Commissioner Camille Calimlim Touton was among those urging water interests throughout the Basin to continue working collaboratively toward solutions and she provided a broad outline of actions that federal officials are preparing to take in 2023 – including reducing water releases from Lake Powell and Lake Mead – to keep the river from crashing. 

“The actions we choose to take over the next two years,” Touton told participants, “will define the fate of the Colorado River for the next century.”

Living Within New Means

Though the Colorado River’s annual yield has shrunk in the 21st century, demand for its diminishing supply hasn’t, creating a glaring math problem for Basin water managers. In a system where every drop of water is already allocated, the specter of an 11 million acre-foot river — or worse — is forcing users to prepare for a drier future. 

One agency that has been actively finding ways to stretch its river supply is Southern Nevada Water Authority, which serves more than 2 million people in the Las Vegas area. The agency has updated its modeling and long-range planning to reflect the river’s changing hydrology. 

John Entsminger, the authority’s general manager, said computer models are sending a direct warning that the Lower Basin will end up with only a slice of the 7.5 million acre-feet per year outlined in the Compact. After accounting for evaporation and system losses, he said, it’s probable the Lower Basin and Mexico will have much less water to split.

“It is incumbent upon the Lower Basin to come up with a plan to live within its 7 million acre-feet release from Lake Powell probably forever going forward and hope it’s not less than that,” said Entsminger.

Like Nevada, Arizona is already feeling the pinch from the latest round of federal water cuts. So far, the two states and Mexico have shouldered most of the pain.

In 2022, Arizona is using approximately 2 million of its 2.8 million acre-feet Colorado River allocation, according to state officials The state’s agricultural industry is taking the hardest hit, including one rural county that fallowed more than 50 percent of its farmland for lack of irrigation water.  

“We’re already seeing huge pain, and with an 11 million acre-feet [river] that pain’s just going to continue to grow,” said Tom Buschatzke, Arizona Department of Water Resources director. 

The widening gap between supply and demand is also having an impact above Lee Ferry, where inflows into Lake Powell continue to fall below historical average. Water from Powell is critical for helping the Upper Basin meet its commitment under the 1922 Compact to deliver water to the Lower Basin.

Representatives from the Upper Basin states say they have collectively cut their annual consumptive river use from 4.5 million acre-feet to approximately 3.5 million acre-feet over the last three years. Over the same period, they argue, the Lower Basin has done little to reduce its own consumptive use. Similar to Arizona, Upper Basin farmers also have been on the receiving end of water cuts. 

The Ute Mountain Ute Tribe has fallowed the majority of its farmland in southwestern Colorado while in Wyoming, more than 100,000 acres of farmland were cut off from surface water for most of August because of low stream flows in the Upper Basin. 

“That equates to about 100,000 acre-feet of [diverted Colorado River water] a month…that’s a third of our average irrigated use,” said Brandon Gebhart, Wyoming State Engineer. 

The Upper Basin states have proposed a five-point plan built around paying farmers to reduce water consumption. Though it doesn’t require mandatory cuts for water users, proponents say the success of the plan hinges on whether the Lower Basin agrees to leave more water in Lake Mead.

“I think we need to recognize that the uses are far outweighing what Mother Nature is providing and that is primarily not in the Upper Basin,” said Mitchell with the Colorado Water Conservation Board. 

California In the Spotlight

California’s use of the river has been a sore point among others in the Colorado River Basin. California, the largest user of Colorado River water, has been spared from water cuts so far due to its senior priority rights and has been using its full 4.4 million acre-feet entitlement in 2022. Groups in both the Upper and Lower Basins say the state must significantly reduce its use to prevent the river system’s collapse.

California water agencies and state officials have pushed back on criticism that they aren’t doing enough to help buoy the shrinking reservoirs.

Peter Nelson, chairman of the Colorado River Board of California, argued California delayed the current crisis by enacting voluntary deals that pay farmers not to plant their fields, transfer water to urban users or make their systems more water efficient.

“In the Lower Basin, since the last seven years or so, we’ve stored 1.5 million acre-feet of water in Lake Mead as Intentionally Created Surplus water,” said Nelson, who farms in the Coachella Valley. “That has enabled the lake levels at Lake Mead to stay high enough to stay out of shortages and benefit other states in the Basin.”

Though the state is using its full share amid another bitterly dry year on the Colorado River, California water managers say they are not dismissing the fact that the river is overprescribed and that future cuts are needed. But they warn that the state’s farmers shouldn’t be made the scapegoat for all the Basin’s water problems.

For example, cutting off water to farmers in the Imperial Valley may help solve one crisis but simultaneously cause another, said Henry Martinez, general manager of the Imperial Irrigation District. Agriculture overwhelmingly drives Imperial County’s economy, he said, so fallowing would lead to major job losses in a region already prone to high poverty and unemployment rates.  

“You can devastate the whole industry by making the wrong cutbacks at the wrong time. There has to be consideration also as to how to prop up or maintain the economy of the region, otherwise you go from a very poor area to devastating even furthermore the economy,” said Martinez.

In response to Reclamation’s call this summer for river users to voluntarily conserve 2 million to 4 million acre-feet of water in 2023 to protect Lake Mead and Lake Powell, Imperial Irrigation District and other California agencies on Oct. 5 proposed a plan that would save 400,000 acre-feet — 9 percent of California’s river allocation — each year between 2023 and 2026.

Earlier this month, the Department of the Interior approved the deal, committing $250 million from the Inflation Reduction Act to kickstart the conservation plan and support Salton Sea restoration efforts. As a result of water conservation efforts and a long-term transfer of farm water from the Imperial Valley to urban San Diego, the sea has been shrinking, exposing more lakeshore to winds that blow hazardous, lung-choking dust into the region.

California’s offer has received mixed reviews throughout the Basin: Some have applauded the proposal and called it an encouraging first step from the river’s biggest user, but others have cast it as an underwhelming opening gambit.

Wade Crowfoot, California Natural Resources Agency Secretary, said the Basin must continue negotiating and taking advantage of federal aid earmarked for Western drought relief to spur water conservation. 

“As challenging and as tense as this is, I think that there’s a real opportunity and that failure is not an option,” said Crowfoot. “Everybody understands we have to figure this out and we have some resources at our disposal.” 

“We can’t be caught flat-footed.”

In June, Reclamation Commissioner Touton told a U.S. Senate panel that unless an emergency conservation deal was reached by river users in 60 days, the federal government would have to take unilateral action to prevent the system’s demise.

But the deadline passed without a deal and there was no immediate federal response, causing water users to wonder whether repercussions were coming. With little progress on a watershed-wide conservation plan, some Colorado River veterans contend the federal government should take a direct role in facilitating negotiations.

“I think Reclamation is going to have to get some key players in the room, probably including Mexico, and really get down to the brass tacks of leveraging and what needs to be done,” said Tom Davis, general manager of the Yuma County Water Users’ Association. “We need to save this patient’s life in the next 24-36 months.”  

Touton’s demand that the Basin states cut 2 million to 4 million acre-feet caught them off guard, said Bruce Babbitt, former Interior secretary and Arizona governor. Since the announcement, Babbitt said, the states have essentially been “stumbling around” in the absence of a well-defined negotiation framework.

Babbitt likened the current situation to the one 100 years ago, when the states’ negotiations on how to split the Colorado River had also stalled before President Warren Harding tapped Herbert Hoover to guide the talks. Babbitt told the September symposium there are important lessons to be taken from the structured discussions at Bishop’s Lodge, just outside of Santa Fe, N.M., that ultimately led to the formulation of the 1922 Compact.

“What finally emerged out of that in terms of process at Bishop’s Lodge is something that I think we need to reflect on because we’re going to have to put together a workable framework,” Babbitt added.

Federal officials contend there isn’t a leadership void.

David Palumbo, Reclamation’s deputy commissioner of operations, said Reclamation is preparing a suite of actions — including reducing releases from Lake Powell in 2023 — to prevent a scenario where water can’t flow out of the system’s main dams.  

“If we need to release less than 7 million acre-feet [from Glen Canyon Dam] … if that hydrology is not there, we’re going to have to do something to avoid the crash and we’re going to be prepared to do that,” said Palumbo. “We can’t be caught flat-footed.”    

With talks between the states and tribes at a standstill, Interior Secretary Deb Haaland on Oct. 28 announced the federal government is considering deviating from operating rules established in 2007 and 2019 to handle water shortages on the river. 

During recent public briefings, federal officials have indicated that Lake Powell releases may be slashed by 2 to 3 million acre-feet annually to keep the reservoir from reaching a point where it could no longer generate electricity or deliver water downstream.

Meanwhile, Reclamation is now offering Lower Basin water users up to $400 per acre-foot of conserved water over the next three years, part of the $4 billion in drought relief funding secured through the Inflation Reduction Act. In addition, at least $500 million will be reserved for water conservation and efficiency projects in the Upper Basin.

Some Colorado River veterans, including Colby Pellegrino, deputy general manager of resources for the Southern Nevada Water Authority, are urging Reclamation to focus the federal drought relief on actions that will not just temporarily halt Lake Mead’s decline, but permanently change water use habits.

“We should be using that money to fundamentally change the way we do everything in this Basin to use the least amount of water possible,” she said.

Considering the scope of the damaging economic, social and ecosystem impacts that would flood the Basin if Lake Mead or Lake Powell were to reach dead pool, others argue Congress should get more involved. One idea, outlined in a policy paper presented at the Symposium by the Foundation’s 2022 Colorado River Water Leaders class, is a biennial program that would provide federal funding for programs that would reduce system demand and encourage more frequent discussions between the states, tribes and other water users in the Basin.

Congress has enacted similar regional programs in recent decades, including in the Florida Everglades, the Chesapeake Bay and the Great Lakes. A stable source of federal funding can create permanent, multi-benefit solutions, said Brenda Burman, former Reclamation commissioner who will take over as general manager of the Central Arizona Project in 2023. 

“Whether it’s biennial or yearly, I think we need to be looking at a Colorado River Basin program,” she said. 

Tribes Gain a Say

Unlike previous deals, the federal government and states say they are committed to figuring out how to share Colorado River water while acknowledging the sovereignty and water needs of Native American tribes.

Many Basin tribes, which hold legal rights to about a quarter of the river’s water, are hoping to upgrade their infrastructure and fully develop their water rights. As the tribes assert their water rights, the amount of water available to states with junior rights like Arizona or Nevada may shrink. After fighting legal battles to secure their rights to the river — 12 Basin tribes still have unresolved water rights claims — tribes aren’t eager to halt the progress they’ve made in bringing water to their communities and farms.

Lorelei Cloud, a member of the Southern Ute Indian Tribe’s tribal council, said the tribe’s unused river water simply flows by its Colorado reservation to be used by others downstream. She reiterated that unused tribal water, which gets treated as “surplus water”, is a vanishing luxury the rest of the Basin won’t soon be able to bank on.

“Tribes don’t get compensated and have never been compensated for our unused tribal water, especially the water that’s sitting in Lake Powell and Lake Mead,” said Cloud.

Decrepit water infrastructure among other issues prevents the Southern Ute from being able to use its full river allocation as it is, so Cloud added that the tribe is unlikely to cut back its water use even if the river continues to shrink.

“When tribes start to develop their water, what are you all going to do?” Cloud asked the Symposium crowd. “Because that water is ours. We’re in Colorado, so we’re going to get our water first.”

While the tribes have been historically excluded from and considered an afterthought in Colorado River negotiations, there are signs that the balance of decision-making power is shifting. Congress is providing billions of dollars in funding in the Bipartisan Infrastructure Law and the Inflation Reduction Act to help tribes across the country improve their drinking water and water delivery systems.

At the September Symposium, both federal and state officials echoed the need for tribes to be included at the bargaining table.

“Tribes across the Basin will also continue to play a vital role,” said Interior Secretary Haaland, the first Native American to serve as a cabinet secretary. “Indian tribes have water rights, and not only are they deeply affected by the drought, but they have been and will be invaluable partners in finding solutions.”  

Other Challenges

Before considering any major changes to the river’s guiding principles, water managers will have to ensure that the country of Mexico is included in the process.

Mexico, already dealing with water shortages in several of its northern cities, is taking cuts to its river supply in 2022 and 2023 under binational agreements. Tensions over sharing the Colorado River have traditionally waxed and waned but the neighboring countries have been able to reach a series of water management agreements in recent decades. 

Members of the International Boundary and Water Commission (IBWC), which oversees boundary and water issues between the U.S. and Mexico, said they are confident the two countries can continue communicating and building on previous partnerships.    

“I feel that we’re going to go very far and be able to identify what we need to solve the issues along the U.S.-Mexico border,” said Maria-Elena Giner, the U.S. commissioner to the IBWC.

Thus far, talks regarding the river’s future have focused on limiting impacts to cities, farms and tribes. But reserving enough water to ensure the Basin’s fish and wildlife survive the drought is another thorny task water managers are wrangling with.

Environmental groups and other nongovernment organizations argue they are key river partners that can bring myriad resources and ideas to the brainstorming process.

“When the system is not sustainable, it’s not resilient and the environment loses. It’s the one that gets sacrificed first,” said Taylor Hawes, The Nature Conservancy’s Colorado River program director. “Finding solutions that do not sacrifice the environment, that do not look at the environment as a sacrificial lamb, need to be part of our collective path forward.”

Meanwhile, new rules that would require Lower Basin users to account for water lost in large reservoirs to evaporation or leaky water delivery infrastructure are in the works. Currently, Upper Basin states are charged for evaporation losses but the Lower Basin is not.

Federal officials estimate as much as 10 percent of the river’s flow evaporates annually, including more than 1 million acre-feet from the Lower Basin. The federal government has announced it may change the evaporation accounting practices by the end of 2024, meaning the Lower Basin could take a significant cut to its share.     

“In these serious times, we need to take the overdue step of assessing how to account for those losses throughout the Basin. This is another tough reality that we must work together to address,” Haaland said.

As water managers attempt to navigate the river’s mounting crises, they can turn to a variety of recent success stories for inspiration.

Cities such as Phoenix, Los Angeles and Las Vegas have shown the ability to decouple water demand from population growth. Restoration efforts at the long-neglected Salton Sea are producing positive results. An innovative water sharing deal is providing economic benefits to the Jicarilla Apache Nation as well as water security for New Mexico and increased river flows for endangered species of fish.

These beneficial programs and decisions — in a refreshing twist from a river history dominated by men — are being crafted with the input of women in high-ranking positions, creating hope on a river in dire straits. 

Instead of court battles that could lead to a federal judge taking over management of the Colorado River, water users need to negotiate with open minds as they chart a path for the lifeline that means so much to so many, said Mulroy, former head of the Southern Nevada Water Authority. To cut through the paralysis that has bogged down negotiations, everyone will have to show the courage to deviate from old agreements and assumptions and prepare for cuts.

“We’re talking about a body of law and a structure we’ve lived with predicated on 17 to 18 million acre-feet,” Mulroy said, “and a reality that has 9 to 11 million acre-feet in the river – the two don’t mesh.”

The Water Desk’s mission is to increase the volume, depth and power of journalism connected to Western water issues. We’re an initiative of the Center for Environmental Journalism at the University of Colorado Boulder. The Water Desk launched in April 2019 with support from the Walton Family Foundation. We maintain a strict editorial firewall between our funders and our journalism.