The Colorado River is in hassle: Now not as a lot water flows into the river as individuals are entitled to take out of it. A brand new concept would possibly trade that, however sophisticated political and sensible negotiations stand in the best way.
The river and its tributaries supply water for roughly 5 million acres of cropland and pasture, hydroelectric energy for tens of millions of folks, game within the Grand Canyon, and demanding habitat for fish and different natural world. Thirty federally known Local American tribes assert rights to water from the Colorado River gadget. Additionally it is crucial supply of consuming water for towns inside the Colorado River Basin, together with Phoenix, Tucson and Las Vegas, and towns outdoor the basin, reminiscent of Los Angeles, San Diego, Salt Lake Town, Denver and Albuquerque.
The seven Colorado Basin states were grappling with easy methods to maintain declining Colorado River provides for 1 / 4 century, revising utilization tips and taking further measures as drought has endured and reservoir ranges have persisted to say no. The present tips will expire in overdue 2026, and talks on new tips were stalled for the reason that states can’t agree on easy methods to steer clear of a long term disaster.
In June 2025, Arizona recommended a brand new way that might, for the primary time, base the quantity of water to be had at the river’s exact flows, somewhat than on reservoir stage projections or historical apportionments. Whilst the proposal has been praised as providing “a glimmer of hope,” coming to settlement on the main points gifts daunting demanding situations for the Colorado Basin.
The Colorado River Compact
The 1922 Colorado Compact divided the 250,000-square-mile Colorado River Basin into an Higher Basin – which incorporates portions of Colorado, New Mexico, Utah and Wyoming, in addition to the northeastern nook of Arizona – and a Decrease Basin, encompassing maximum of Arizona and portions of California and Nevada. The compact apportions every basin 7.5 million acre-feet of water from the river every yr. An acre-foot of water is sufficient to quilt 1 acre in water 1 foot deep, which quantities to roughly 326,000 gallons. Consistent with a 2021 estimate from the Arizona Division of Water Sources, 1 acre-foot is enough to delivery 3.5 single-family families in Arizona for 365 days.
Expecting a long term treaty with Mexico for sharing Colorado River water, the compact specified that Mexico will have to be provided first with any surplus to be had and any further quantity wanted “borne equally” through the 2 divisions. A 1944 water-sharing treaty between Mexico and the U.S. promises Mexico no less than 1.5 million acre-feet of Colorado River water yearly.
The compact additionally specified that the Higher Basin states of Colorado, New Mexico, Utah and Wyoming “will not cause the flow of the river … to be depleted below an aggregate of 75,000,000 acre-feet for any period of 10 consecutive years.”
The Decrease Basin states of Arizona, California and Nevada contend that this provision is a “delivery obligation,” requiring the Higher Basin to make sure that over any 10-year duration, a complete of no less than 75 million acre-feet flows to the Decrease Basin.
In contrast, the Higher Basin states contend that the language simply creates a “non-depletion obligation” that caps their collective use at 7.5 million acre-feet consistent with yr in instances when further use through the Higher Basin would purpose lower than 75 million acre-feet to be dropped at the Decrease Basin over a 10-year duration.
This confrontation over the compact’s language is on the center of the diversities between the 2 basins.
Snow fall in Western mountains, together with the Flatirons outdoor Boulder, Colo., is the principle supply of water for the Colorado River Basin.
AP Picture/Thomas Peipert
A small supply space
Just about the entire water within the Colorado River gadget comes from snow that falls within the Rocky Mountains within the Higher Basin. About 85% of the Colorado Basin’s flows come from simply 15% of the basin’s floor space. Lots of the remainder of the basin’s lands are arid or semi-arid, receiving lower than 20 inches of precipitation a yr and contributing little to the flows of the Colorado River and its tributaries.
Rain and blizzard range dramatically from yr to yr, so over the process the 20 th century, the Colorado Basin states – with the help of the U.S. Bureau of Reclamation, the company of the Division of the Inner chargeable for working federal water and tool initiatives within the U.S. West – evolved a fancy gadget of reservoirs to seize the additional water in rainy years so it may well be to be had in drier years. Essentially the most notable reservoirs within the gadget are Lake Mead, impounded through Hoover Dam, which was once finished in 1936, and Lake Powell, impounded through Glen Canyon Dam, finished in 1966.
Over the last 25 years, the volume of water saved in Lake Mead and Lake Powell has declined considerably. A number one driving force of this decline is a long drought most likely amplified through local weather trade: One find out about estimated that the area is also struggling its driest spell in 1,200 years.
However human mistakes also are including up. The Colorado Compact’s authentic negotiators made unrealistically constructive assumptions concerning the river’s reasonable annual glide – in all probability knowingly. Of their e-book “Science be Dammed,” Colorado River mavens Eric Kuhn and John Fleck report how compact negotiators willfully or wishfully disregarded to be had knowledge concerning the river’s exact flows. Kuhn and Fleck argue the negotiators knew it could be a long time ahead of call for would exceed the river’s water delivery, and so they sought after to promote a large imaginative and prescient of Southwestern construction that might advantage huge federal financing for reservoirs and different infrastructure.
As well as, the present Colorado River gadget accounting does no longer issue within the kind of 1.3 million acre-feet of water misplaced yearly from Lake Mead because of evaporation into the air or seepage into the bottom. This accounting hole signifies that underneath commonplace annual releases to fulfill the apportionments to the Decrease Basin and Mexico, Lake Mead’s water stage is often declining.
Stabilization efforts
The seven Colorado River states and Mexico have taken vital steps to stabilize the reservoirs. In 2007, they agreed to new tips to coordinate the operations of Lake Mead and Lake Powell to stop both reservoir from achieving catastrophically low ranges. Additionally they agreed to cut back the quantity of water to be had to Arizona and Nevada relying on how low Lake Mead’s ranges cross.
When the 2007 tips proved inadequate to stay the reservoir ranges from declining, the Colorado Basin states and Mexico agreed in 2019 to further measures, authorizing releases from Higher Basin reservoirs underneath positive stipulations and extra cuts to water customers within the Decrease Basin and Mexico.
By means of 2022, projections for the reservoir ranges regarded so dire that the states began negotiating further near-term measures to cut back the quantity of water customers withdrew from the river. The government helped out, too: $4 billion of Inflation Aid Act investment has helped pay the prices of water-conservation measures, basically through agricultural districts, towns and tribes.
Those discounts are actual. In 2023, Arizona, California and Nevada used best 5.8 million acre-feet of Colorado River water – their lowest blended annual intake since 1983. The Decrease Basin’s general intake in 2024 was once reasonably upper, at 6.09 million acre-feet.
Lake Powell, a key Colorado River reservoir, holds best one-third as a lot water as it’s designed to include.
Rebecca Noble/Getty Pictures
A brand new alternative?
With the 2007 tips and extra measures expiring in 2026, the cut-off date for a brand new settlement looms. Because the Colorado River states attempt to figure out a brand new settlement, Arizona’s new proposal of a supply-driven way provides hope, however the satan’s in the main points. Vital elements of that way have no longer been ironed out – for example, the proportion of the river’s flows that might be to be had to Arizona, California and Nevada.
If the states can’t agree, there’s a likelihood that the secretary of the Inner, appearing during the Bureau of Reclamation, would possibly make a decision on his personal easy methods to steadiness the reservoirs and what kind of water to ship out of them. That call would nearly surely be taken to courtroom through states or water customers unsatisfied with the end result.
And the Decrease Basin states have stated they’re totally ready to visit courtroom to put in force what they imagine to be the Higher Basin’s supply legal responsibility, which, the Higher Basin has answered, it’s ready to dispute.
Within the period in-between, farmers in Arizona’s Yuma County and California’s Imperial County can not make sure that in the following couple of years they are going to have sufficient water to supply iciness greens and melons for the country. The Colorado River Basin’s municipal water suppliers are frightened about how they are going to meet calls for for faucet water for houses and companies. And tribal countries concern that they’re going to no longer have the water they want for his or her farms, communities and economies.
