Photo: The Blue River flowing through Silverthorne just below Dillon Dam in May 2025. Photo/Allen Best.
This story by Allen Best appeared on BigPivots.com on August 18, 2025. We are sharing it in two parts.
For many months, all reports suggested that the four-upper basin states — who speak with one voice in these negotiations — and the three lower-basin states remained far apart. A story on June 27 in the Las Vegas Review Journal described the meetings as “tense” and “deadlocked.”
Wyoming, Utah and New Mexico along with Colorado constitute the upper basin. Arizona, Nevada and California make up the lower basin.
Becky Mitchell, Colorado’s representative in the negotiations, told a forum in Silverthorne covered by Big Pivots in May that hydrologic risk must be shared between the upper basin and the lower-basin states.
This sore spot has long festered. The Colorado River Compact of 1922 specified that the upper basin states “will not cause the flow of the river at Lee Ferry to be depleted” below an aggregate of 75 million acre-feet for any 10 consecutive years. The location is between Glen Canyon and the Grand Canyon.
But what if the river fails to deliver that much water? Upper basin states have delivered that volume so far, but that’s mostly because Wyoming, in particular, has not developed what was expected 100 yeas ago.
Those who had originally gathered in Santa Fe in 1922 to negotiate the compact had understood drought, but only as a temporary thing. They had no extensive long-term perspective — and chose to ignore what evidence was at hand, according to a 2019 book by Fleck and Kuhn, “Science be Dammed: How Ignoring Inconvenient Science Drained the Colorado River.”
Colorado’s beef and that of other upper-basin states has been that the two big dams on the river provided certainty for the lower-basin states to get water. However, the headwaters states have no certainty. They must live with what Mother Nature provides. They have balked at cutting water use to provide certainty for downstream states. They want the risk shared.
Natural flow proposal
In June came the first public word of what may have been a breakthrough. It is called the “natural flow proposal.” As explained by Tom Buschatzke, the director of Arizona Water Resources, to the Arizona Republic in a story on June 18, the idea is to focus less on who gets what and more on what the river can realistically provide.
“We do have to recognize what the hydrologic risks are to us,” he said after presenting the idea to a committee,” and we have to kind of find an equitable way to share those risks.”
That idea being discussed would employ a rolling three-year average of the natural flow of the river. Natural would be defined as the volume if there were no diversions and impoundments.
Buschatzke — a frequent visitor at the Colorado River forum sponsored by the University of Colorado’s Getches-Wilkinson Center each June — pointed out that the goal would be to spread the pain equitably, not equally. The lower basin would need more water than the upper basin, which has still to develop all the water allocated it in the 1922 compact.
“It is not 50-50,” he told represents at the June 17 meeting. “I won’t try to speculate on what the number might be.”
California uses the most water of any state in the Colorado River Basin, partly for its cities along the Pacific Coast but a substantial amount for agriculture in the Imperial Valley. Photo December 2015/Allen Best
A few weeks later, John Entsminger, Nevada’s representative in interstate talks, similarly was vague about details. “It’s not something where I can tell you what the score is in the third inning: the baseball game is still being played,” he told the Las Vegas Review-Journal.
Details remain sparse, he added.
“Everybody’s pretty much accepted that we’ve got to come up with a new formula for dividing the river,” Mark Squillace, an environmental law professor at the University of Colorado, Boulder, told the Las Vegas newspaper. “The devil’s in the details about getting the numbers right.”
According to the best information that Big Pivots was able to obtain, there is still no agreement about what the percentage should be, although it is not 50-50.
Mitchell, Colorado’s representative on the Upper Colorado River Commission (and its acting chair), told the Review-Journal that the 2007 guidelines that provide the management map of the river’s operations “are not sustainable, because the water is just not there. It’s not in storage, and it’s not in the river.”
For a late-June story in Politico’s E&E, Mitchell described the natural flows idea as a math problem. “The concept under discussion is that Powell would release a certain percentage of volume of the average of the last few years of natural flows, as measured at Lee Ferry,” she said.
E&E described a more complex challenge.
“The theory — the premise of sharing the river based on how much water would travel downstream without dams or diversions or other human interventions — is actually a complex mathematical problem, rife with potential pitfalls and technical issues.”
This idea of basing releases from Lake Powell likely would take several years to implement. As such, it would not immediately impact levels in the reservoir.
As for the minimum power pool at Powell, that’s the level at which hydroelectricity can no longer be generated. Some 16 municipal and cooperative electrical utilities in Colorado get power from the dam. Those amounts tend to be smaller, about 5% or less, although important if the utilities are stretching to achieve decarbonization goals.
The greatest value of Glen Canyon is that if the Western grid has a blackout, the grid can be restarted with hydropower from the dam.
And too, the role of Congress
As administrator of the two big dams in the basin and several smaller ones, the federal government must figure out how to manage them consistently with the agreements among the states. It is also the formal administrator among the lower-basin states.
At the conference in Boulder, Cameron clearly said the federal government wants the states to figure out the solution. However, he also said that if the states cannot come to agreement, the federal government, as the administrator of the infrastructure, has authority to set policy, too.
And finally, he mentioned that the whole package may need to go to Congress, as was the case with the Colorado River Compact. It was approved in 1929.
Arizona had refused to endorse the compact until much later.
Allen Best publishes the e-journal Big Pivots, which chronicles the energy transition in Colorado and beyond.