The Colorado River is at a pivotal crossroads. People are taking more water out of the river than it can provide, and the policymakers that manage water use cannot agree on how to rein in demand.
That has left the river — and the nearly 40 million people who use it — hanging in the balance. Across seven Western states, major cities, tribes, and powerful economies are stuck in a moment defined by low reservoirs, high-stakes legal tension and an uncertain future.
This fall, a new federal plan for cutting back water use has triggered legal action from Nevada, Arizona and the massive canal system that brings Colorado River water to the Phoenix area.
But this tense moment and this 21st century crisis are not showing up as a complete surprise.
In fact, the architects of that canal system gave explicit warnings that its position near the front of the line for cutbacks would mean lower flows in the future. The warnings they issued in the 1960s appear to have been largely ignored in the decades since, and the fingerprints of their ambition are still shaping the headlines of today.
How we got here
Phoenix and Tucson as we know them today wouldn't exist without a gravity-defying, 336-mile system of canals, pipelines and pumping plants that cut through the desert, collectively known as the Central Arizona Project, or CAP.
Today, water shortages threaten the expensive, improbable system, and a series of warnings about the canal's future from the 1960s, seem prescient.
"It's an engineering marvel," said Rich Weissinger, who spent nearly 30 years working for the organization that operates the canal.
Weissinger, who most recently worked as director of field maintenance for CAP, stood inside one of the pumping plants that keeps water flowing through the canal. Inside the facility, motors and turbines kicked into action and emitted a steady, thundering whir.
The moving parts that keep this system running are rock solid, held in massive casings of riveted metal that wouldn't look out of place on a battleship.
"We have lots of people, lots of industry, lots of municipalities that depend on a stable water source," Weissinger said. "and that's what CAP can bring — a stable, reliable water source."
But now, unprecedented dry conditions in the Colorado River basin are putting some of that reliability into question. The 21st century has seen record-breaking drought supercharged by climate change. Steady withdrawal from cities and farms across the seven states that use the Colorado River have left its water supplies pinched between supply and demand.
Taking more than the river can give
As policymakers have scrambled and failed to come up with a regionwide compromise that would rein in demand, the nation's two-largest reservoirs have shrunk to record lows. In response, a controversial set of plans would cut a significant chunk of Arizona's annual take from the Colorado River.
They could mean a 47% cut to the amount of water allocated to the Central Arizona Project.
But today's problems did not come without warning. The architects of the CAP, 1960s policymakers who championed it as a promising part of Arizona's future, were clear about the fact that it would not work forever without extra help. They publicly forecasted big drops to its flows in the 21st century and laid out a plan to avoid them.
They called for augmentation, or the addition of outside water supplies, to the Colorado River water that flowed through the canal. They suggested a connection between the Colorado River system and the Columbia River system in the Pacific Northwest. They considered massive desalination facilities on the Pacific Coast. Now, decades later, we know those suggestions never became reality.
It seems like the warnings of dropping flows, and the plan to deal with those shortages, were ignored along the way. But the water experts of today say the reality is complicated, and there are good reasons why advice from the 1960s went unheeded, even as Arizona faces sharp water cutbacks that could reshape its future.
A warning, largely forgotten
When the Central Arizona Project was signed into reality, then-President Lyndon B. Johnson waxed poetic about its promise. In a video from the organization's archives, he stands in front of a crowd and speaks over optimistic, swelling violin music.
"It'll provide more water for growing cities, more water for expanding industries, for the farmer's crops, and for the rancher's cattle," Johnson said of the CAP.
But people in the audience that day, some of the CAP's loudest proponents, were frank about the limits of the project.
Floyd Dominy, then commissioner of the Bureau of Reclamation, laid out specific estimates for the amount of water it might divert in the future. He forecasted big declines between 1990 and 2030, suggesting that its available supplies would be more than halved in that time.
Dominy and others guessed that the amount of water available for the CAP would go down specifically because of growing use in the upstream states of Colorado, New Mexico, Utah and Wyoming, not because of drought and climate change, which turned out to be the primary driver of declining water supplies in the 21st century. Regardless, Dominy and others were broadly correct that less water would be available to divert toward Phoenix and Tucson.
Congressman Mo Udall, a Democrat from Arizona, was also a vocal supporter of the CAP. He was candid about the need for more water in it. Testifying in front of Congress in 1968, he made it clear that it was necessary to bring in additional water.
"Let's assume there is no augmentation in the river — not a drop," Udall said. "I think this is a very violent assumption, because I am as sure as anything in this life that there will be augmentation."
The idea of augmentation via a connection to the Columbia River felt so real at the time that senators from the Pacific Northwest felt the need to protect the Columbia by adding a section to the legislation that authorized the CAP. The bill's proponents agreed to include that language — meaning that the federal government would be barred from even studying a plan to move water into the Colorado River from any other river system for ten years after the law passed.
Despite that certainty, dreams of augmentation in the 1960s never materialized.
"There was no willingness to spend money to address a future problem that wasn't here yet, and that I think people were not sure whether it was going to materialize or not," said Tom McCann, a former deputy general manager for the CAP.
For decades, the CAP has diverted water into central Arizona. It has never been helped by a major infusion of desalinated water from the Pacific Ocean or a pipeline to the Pacific Northwest.
"The warning that had been issued before, if you want to think of it that way, was largely forgotten," said McCann, who has extensively studied the CAP's history.
He said augmentation was not written off completely by decades of CAP managers, but they also did not think that water shortages would get this dire.
"We didn't think that the large-scale augmentation things were harebrained ideas," McCann said. "In fact, we tried to keep looking at them and studying them and figuring out how we could implement them. They were challenging, was the problem, challenging in multiple aspects."
McCann said cost and political hurdles got in the way.
Kicking the can down the road
Now that Arizona is in the grip of steep water shortages and major threats to the singular purpose of the CAP, the warnings from the 1960s have taken on a new, eyebrow-raising tenor.
Was it a mistake to build the massive, ambitious canal and then fail to build the kinds of backups its designers said would be necessary?
Mo Udall and his brother Stewart, who was secretary of the Interior from 1961 - 1969, gave fairly explicit notice that augmentation needed to be a part of the CAP's future. Was it a mistake to ignore them?
Today's water experts generally say no. Including a very important one.
"I think Stewart and Mo sort of blew it on some of this," said Brad Udall, Mo's son and Stewart's nephew.
The younger Udall is a widely-respected water thinker in his own right, working as a senior water and climate research scientist at Colorado State University. He said his dad, uncle and their colleagues could have done better than suggesting complicated, expensive and unlikely augmentation as a fix for the CAP's future deficiencies.
But, Udall argued, they deserve some forgiveness.
The brothers grew up on a farm in rural eastern Arizona during the Great Depression, and by the time they were in the halls of power, an era of booming national optimism may have colored their political thinking.
When the CAP was proposed, America was riding high. In the mid-1960s, a World War II victory was still fresh in mind, and the nation was on the tail end of an era that brought about the interstate highway system and dams that still stand as the country's largest. So, in the context of the time, it makes sense that they suggested fixing future water shortages by throwing more concrete at the problem.
"The 1968 idea was we could build our way out of anything," Brad Udall said. "We could engineer our way out of every crisis. We're smart. We're rich. The world's our oyster."
On top of that, many of the CAP's proponents were likely exhausted. Discussions and negotiations about the canal were happening shortly after a years long legal battle between Arizona and California. It ended in a landmark Supreme Court decision and decree that, among other things, paved the way for the CAP.
Udall said after the court battle, proponents of the canal "just wanted to get this thing across the line," and their pitch for augmentation was a hasty, if half-baked, way to do that.
"They figured, like many humans do, we'll do some of the hard work later," Udall said. "This is a massive project, and we don't have all the answers now. We're going to kick the can down the road and hope it all works out."
The future of farms and desalination
There's another reason to believe that promising augmentation was a politically convenient decision. Desalination plants and across-basin pipeline help policymakers ignore an elephant in the room.
"I have a strong thesis that this is a way to avoid saying Phoenix is going to grow at the expense of agriculture," said Chuck Podolak, former director of the Water Infrastructure Finance Authority of Arizona.
Farms and ranches account for roughly three quarters of all Colorado River water use. Because huge quantities are used for growing relatively cheap crops, water is more valuable in cities, where the same amount can be spread across many homes and businesses. Water experts say it would be complicated, but more affordable, for cities to buy water from farms rather than build huge new infrastructure.
But if you can afford augmentation, Podolak said, you can avoid the tough political fight it would take to reallocate water from farms to cities.
He said ideas from the 1960s shouldn't be seen as "founding father documents," but rather the product of "fallible people" needing to get short-term political success.
"I think we might be naive to assume complete honesty and wonderful intent by everyone back then," Podolak said, "Just because it's written in black and white on a piece of paper."
However, he said we shouldn't write off all of their ideas completely.
As today's Colorado River cuts squeeze Arizona cities, cities have warned that billions of dollars in public spending will be needed to help them adapt in the long term. Utility managers have outlined the need for new groundwater pumping systems, water treatment plants and pipes to move limited supplies to the places they're needed. All of that will cost a lot of money.
Podolak said a connection between Arizona and the Columbia River is unlikely, but ocean desalination — which filters salty seawater into fresh drinking water — deserves consideration.
His former agency was promised $1 billion in 2022 to find new sources of water. Even though big chunks of that funding have been withheld in the years since, it is actively exploring a handful of proposals to build coastal desalination plants.
"I do think it can be built," Podolak said. "I think it can be done. I think it all comes down to — at what cost? And are the people of Arizona, the ratepayers of Arizona, the elected leaders of Arizona, willing to pay or invest in that cost right now? But I don't see that as a foolish undertaking."
Others say big, new ocean desalination plants are so expensive and politically complicated that it's more worthwhile to invest in other ways to access purified water first.
For example, the Central Arizona Project is exploring a transfer deal with the San Diego County Water Authority, which runs the largest desalination facility in the Western Hemisphere, near the beach in Carlsbad, California. Under a potential deal, San Diego would pull more water from the ocean and leave some of its Colorado River water behind, allowing Arizona to take it instead — for a price.
Closer to home, some cities are investing hundreds of millions into wastewater recycling plants, using a method they have dubbed "advanced water purification." Those facilities can take sewage and turn it back into safe, clean drinking water. Max Wilson, water resources management advisor for the city of Phoenix, said they use a technology very similar to the kind used at ocean desalination plants.
"We actually are doing [desalination] here, but we're doing it right here in the Valley, and we're doing it through advanced water purification," Wilson said during a live event hosted by KJZZ.
A fundamental problem, and a real way to fix it
The CAP's designers may not have had the perfect solution, but they were mostly right in diagnosing the problem. People are asking for more water than the Colorado River can provide on its own. So there may be some lessons to learn from a close read of the comments made while the CAP was being drawn up.
"I wouldn't say it's helpful to look back at the architects and blame them, but it's helpful for today," said John Berggren, regional policy manager for the environmental nonprofit Western Resource Advocates. "Every decision has to be made in that context. We don't have an unlimited supply. We're probably not going to build the new big pipeline anytime soon, so let's find every way to tighten our belts here."
Berggren, who researched the CAP's conception for his Ph.D. thesis, said the canal's designers knew that there was a fundamental problem in the bedrock of management plans for the Colorado River. Even before the current era of shortage, Arizona was promised an unsustainably large volume of water. Most years, Arizona and its neighbors pull more water from Lake Mead — the nation's largest reservoir — than flows into the lake and refills it.
That leaves the Colorado River in a state of imbalance, often referred to as a "structural deficit." Berggren said people across the seven states that use the river have to revisit the fundamental management of its water and cut back on demand.
"Everyone across the Colorado River basin is going to have to help chip in and use less water because that's how the system was designed," he said.
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