The negotiators who wrote the Colorado River Compact pose for a photo in 1922. They were deliberate in choosing their words, which still shape a river that supplies 40 million people more than a century later.
The future of the Colorado River hangs in the balance. The states that will decide its future are stuck at an impasse. They can’t agree on a plan to divvy up the shrinking water supply.
At the heart of that disagreement are three words written over 100 years ago.
It’s all rooted in a document called the Colorado River Compact. None of its authors are alive today, but the words they wrote in 1922 are still shaping life for millions today.
“The content of this particular document, the Colorado River Compact, is the foundation of the law that is governing the Colorado River at this point,” said Patty Rettig, who manages the water archive at Colorado State University’s library.
Her archive includes the writings of Delph Carpenter, one of the eight men who penned the original document. Sitting at a library table, Rettig carefully flips through the pages of his notes — thin, carbon-paper drafts marked up with pencil — looking for clues from history about how we arrived at the water policy fights of the 21st century.
“I know they were thinking about the future,” she said. “We have evidence they were thinking about the future, but I don't think they were thinking 100 years into the future.”
Taking a closer look at those three words — why they were chosen a century ago and how they’re being interpreted today — tells us a lot about the big, complicated problems facing the Southwest’s most important water supply.
Where are we now?
The Colorado River supplies 40 million people across seven Western states and parts of Mexico. Rules about sharing water are decided by representatives of those seven states. Mostly appointed by governors, they meet, usually behind closed doors, to decide who should get how much.
Right now, the clock is ticking for them to agree on new guidelines for water sharing since the current set of rules expires in 2026. Meanwhile, more than two decades of dry conditions have only increased pressure for the entire region to cut back on demand. The Colorado River has been in the grips of a megadrought, fueled by climate change, and demand has remained mostly steady.
As a result, the region’s reservoirs have plummeted to record lows, and big changes are needed for a sustainable future.
In March, the states split into two camps and published their ideas for managing the river after 2026. Those two groups were divided along familiar lines. The Upper Basin states of Colorado, Utah, Wyoming, and New Mexico found themselves pitted against the Lower Basin: California, Arizona, and Nevada.
Those two camps have been at odds since the earliest days of Southwestern water management, and 2024 is no exception.
What do they disagree about?
The two proposals for managing water lay out a major philosophical difference between the Upper and Lower basins. They disagree about who should take responsibility for the gap between supply and demand.
The Upper Basin is legally required to let a certain amount of water flow to its downstream neighbors each year. After more than 100 years of complying with that standard, Upper Basin states want the ability to allow less water to flow, and their proposal puts that idea into writing.
About 85% of the Colorado River starts as snow in the Upper Basin’s mountains. Climate change, the catalyst for the region’s water shortages, is shrinking the amount of snow that falls in those mountains each year. Because of that, the Upper Basin states argue, they feel the sting of climate change more sharply than the Lower Basin. Cities and farms within its four states have to adjust their water use in accordance with recent snowfall, Upper Basin leaders say, but the Lower Basin can count on predictable water deliveries from upstream.
The Upper Basin’s proposal basically outlines a legal loophole that would let them, under certain circumstances, allow less water to flow downstream without breaking their contract with California, Arizona, and Nevada.
“[The proposal] protects Lake Powell storage for the benefit of both the Upper and Lower Basins, mitigates the risk of either Lake Powell or Lake Mead reaching dead pool, and is consistent with the Law of the River,” the Upper Basin states wrote in their proposal.
What are those three words?
In 1922, eight men holed up at a lodge in Santa Fe, New Mexico, and spent 11 months going back and forth about the language of the Colorado River Compact. They were very deliberate in their choice of words.
One of the most important ideas laid out in its pages is the division of water between the Upper and Lower Basin. Half of it — 7.5 million acre-feet — stays in the mountain states where it starts as snow. Those Upper Basin states are on the hook to let the other half flow downstream.
Article III, Section D of the Compact explains it this way.
“The States of the Upper Division will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75,000,000 acre-feet for any period of ten consecutive years reckoned in continuing progressive series beginning with the first day of October next succeeding the ratification of this compact.”
The water leaders of Colorado, Utah, Wyoming, and New Mexico are today, zooming in on one tiny part of that sentence.
“Will not cause.”
The Upper Basin states, in 2024, say the agreement does not require them to send a particular amount of water downstream every year. Instead, it requires them to not be the reason that amount doesn’t make it downstream.
They’re arguing that climate change, not the states themselves, is the reason that less water is making it downstream. The Upper Basin states say they have less water to begin with, and it isn’t their fault – it’s the fault of a warming climate.
And they’re saying the Colorado River Compact, written more than a century ago, gives them legal permission to allow less water to flow downstream because they aren’t the ones causing the water supply to go down.
Whose idea was this?
The Colorado River Compact has not always been interpreted in this way. The idea to blame climate change as the “cause” of depleting water supplies, by most accounts, came around in the early 2000s. The people who drew it up are still around today.
“I might have been one of them,” Eric Kuhn said with a chuckle. “I plead guilty.”
Kuhn, now retired, was the head of the Colorado River District from 1996 to 2018. The taxpayer-funded agency was founded to keep water flowing to the cities and farms of Western Colorado. He said warming temperatures, which pushed river supplies into a steady decline starting around the year 2000, was the spark for the idea.
“We have fixed obligations at Lee Ferry, and because of climate change, we're going to see less and less water in the river,” Kuhn said. “A fixed obligation with a declining resource means our water supply is caught between the two. So, I called it the ‘Upper Basin squeeze.’”
Lee Ferry, also called Lee’s Ferry, is a place on the Colorado River in Northern Arizona. The architects of the Compact designated it as the river’s halfway point. The measuring equipment installed there is still important today.
Kuhn doesn’t blame today’s water leaders for pushing the idea during negotiations about the future. He said they wouldn’t be doing their jobs if they didn’t highlight climate change. But he doesn’t see this interpretation — the idea of “not causing” drops in the water supply — as the silver bullet to the Upper Basin's water woes “I think it's a negotiating stance,” Kuhn said, “And hopefully will give them some maneuvering room to come up with a different proposal than what they're saying right now.”
What did the Compact’s authors mean?
A certain faction of powerful people are choosing to interpret the language of the Colorado River Compact in a very specific way. But was that the intention of the people who wrote it?
In short, it’s hard to tell. But people with a knowledge of water history think they probably weren’t trying to create a loophole. Patty Rettig, the archivist at Colorado State University, has read through a lot of documents that can provide some context.
The collection she manages contains extensive writings from Delph Carpenter. He was Colorado’s delegate to the 1922 meetings that resulted in the Colorado River Compact. His family turned over his papers, which includes an original copy of the Compact itself, to the CSU library. The collection also includes pages upon pages of handwritten notes and work-in-progress drafts that accrued during the months-long deliberations.
Rettig has read through the meeting minutes from 1922 – a word-by-word transcription of what state negotiators talked about during their brainstorming sessions in Santa Fe. She does not think Delph Carpenter would have deliberately chosen wording about the Upper Basin’s delivery obligation to provide 21st-century leaders a way to find some wiggle room in how they manage water.
“I think it is plausible, but I think that also might be stretching his intentions some,” she said. “I don't have the sense that he was trying to do something underhanded or trying to get specific benefits for his state.”
The compact’s authors — a group that also included representatives from six other states and Herbert Hoover, who was the U.S. Secretary of Commerce at the time — may not have been thinking about water policy discussions in the year 2024, but they were decidedly choosy with their wording.
Flipping through a mishmash of undated drafts of the Compact, many marked with Carpenter’s own scribbles and notes, that now-important “will not cause” sentence takes a few different forms.
At one point, the authors write that the Upper Basin states will not cause the river to be “diminished” below the set amount of water. At another, they use the word “reduced.” Finally, they settled on “depleted.”
But throughout all of the drafts, or at least the ones that made it into CSU’s collection, they did not change the wording about the Upper Basin’s responsibility to not “cause” the river to drop.
What happens if this goes to court?
The Upper Basin’s idea was met with swift dismissal from downstream states. JB Hamby, California’s top water negotiator, put that dissent into words.
“Arguing legal interpretations until we’re all blue in the face doesn’t do anything to proactively respond to climate change,” Hamby said in a press conference on March 6, the day the proposal was released.
For Robert Glennon, water law expert and professor at the University of Arizona, the Upper Basin’s argument only makes sense if you laser-focus on those three words — “will not cause” — and ignore the context of the Colorado River Compact as a whole.
He said it’s a simple document, laying out a sequence of steps to split the river in half at Lee’s Ferry. The document itself is only a few pages long. It was written before Glen Canyon Dam and Hoover Dam were built or extensive canals tapped the river’s flow.
Glennon said the compact’s authors “didn’t know what the Upper Basin states might do, but they wanted to make sure there was no hanky-panky.” The phrase in question, demanding the Upper Basin send water downstream, simply reinforces the agreed-upon split.
That, in Glennon’s mind, is the most “sensible interpretation” of the Compact’s language. But if the states decide to take the question to court, Glennon said, a lawsuit over the language “would be a disaster.” “What, you’re trying to cram modern theories and the science of climate change into a 100-year-old document?” Glennon said.
He pointed out the Colorado River Compact is short — considerably shorter, he joked, than a lease for an apartment. It doesn’t contain any legal definitions for key words like “depleted” or “cause.” No one could predict what the courts would do, and court cases over Western water rights, in the past, have sometimes dragged on for years or even decades.
Glennon adds that if the Upper Basin really wanted to reopen the terms of the Colorado River Compact in a courtroom, there is a stronger argument at hand. The founders who divided up the water in 1922 judged the river’s flow by a period of extremely wet years — in fact, some of the wettest in more than a thousand years. Even setting aside long-term drought and climate change, the compact divvied up more water than the river normally holds. In legal terms, that’s called a “mutual mistake” – and it’s the kind of thing a lawyer could use to void a contract.
“I think that’s a legal argument with some heft to it,” Glennon admitted.
But he wasn’t suggesting anyone take that road. Glennon said it’s in no one’s interest to tear apart the Colorado River Compact. Instead, he expressed faith in the ongoing negotiations.
“We’re pretty close to finding ways to get through this really quite terrible period,” he said. “The people who are working on these issues at the state and federal level are smart, they’re earnest, they’re determined to get through this, and I think they will.”
What’s next for negotiations?
Glennon isn’t the only one who believes the states can hash this out at the negotiating table without leaning on controversial readings of old laws.
Jim Lochhead was Colorado’s top water negotiator in the late 90s, and among the first people to push the “will not cause” interpretation. But now, he said, isn’t the right time for lawyers to make “arcane and complex arguments.”
“Making strident arguments about those interpretations ultimately ignores the responsibility of the basin states to come together and reach agreement on managing a crisis that we all face together as a basin,” Lochhead said.
His comments join a chorus of other Colorado River experts who, despite their differences about how exactly to solve the supply-demand crisis, agree on one thing: the river’s future should be decided by the Western states that use its water.
“I think the fundamental lesson is that we're much better off controlling our own destiny than putting our future in the hands of nine justices on the United States Supreme Court who don't understand Western water law, who don't understand life in the West,” Lochhead said.
Proposals from both basins are on the desk of the Bureau of Reclamation, the federal agency that manages Western dams and reservoirs. They’re joined by suggestions from tribal nations and a coalition of environmental nonprofits.
Reclamation officials are calling on the states to find some consensus before the November election, so federal water managers can start the paperwork to implement post-2026 river management plans before any potential disarray that could be caused by a change in presidential administrations.
In June, state water negotiators said they plan to take longer than that, hinting that they are more likely to find common ground closer to the 2026 deadline.
This story is part of ongoing coverage of the Colorado River, produced by KUNC in Colorado and KNAU in Arizona. It is supported by the Walton Family Foundation.
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