The rules to manage a shrinking Colorado River are mostly set. Finally.

The federal Bureau of Reclamation has released its long-awaited Final Environmental Impact Statement (FEIS) on the river without full buy-in from the seven river basin states.

No one likes the plan. But it generally stuck to the topline details that federal officials released earlier in the summer:

This is a 10-year deal, broken into 2-year chunks unless the basin states miraculously agree to something longer, containing a wide range of probable outcomes that — depending on the user — could be partially horrible or totally catastrophic.

This offers some certainty for how we move forward.

Yet little about the supporting details feels certain.

Why is certainty important?

The arid West cannot prosper without a reliable, long-term water supply.

We need this kind of certainty to make wise water management decisions, to decide which crops to plant, to attract outside economic investment and secure loans to make those investments ourselves.

For decades, the Colorado River was seen as the utmost in reliability — so much so that most cities in metro Phoenix base their required 100-year water supplies on it.

But the river is shrinking. Flows are down a third on average since 2020, to about 10 million acre-feet a year.

This, despite a century of water law that all but guarantees the seven basin states access to at least 15 million acre-feet.

Even 20 years ago, when shortage planning began in earnest, the rules were set to offer certainty — so cuts could proceed predictably for all involved.

That’s no longer the case.

Water cuts could run the gamut

According to the FEIS, annual water releases from Lake Powell could be as low as 5 million acre-feet, which could tank Lake Mead, or as high as 12, which could build it up.

(Given projected elevations at Lake Powell, however, annual releases of 5 million acre-feet are far more likely.)

Mandatory water cuts also are most likely to vary between 1.5 million acre-feet to 3 million acre-feet a year — a painful cut for Central Arizona Project users at the low end, but a catastrophic one on the high end that could dry up the canal and hamper Yuma’s ability to feed the nation in the winter.

These are vastly different scenarios that require vastly different responses.

The intent is to offer a broad breadth of possibilities to better match conditions and offer flexibility as states develop new operational plans every two years.

But it also ensures that states remain in a constant state of negotiation — and uncertainty about their future.

This changes Colorado River planning

It may take a few weeks or months to fully understand what that means.

Reclamation released its FEIS but has not yet issued a Record of Decision or the first 2-year operating plan. Both could come within days, with no opportunity for public feedback.

The agency is expected to adopt most of the Lower Basin’s 2-year plan, though it could deviate on some important and likely controversial water storage and savings details.

That will take time to sort through.

And even then, it doesn’t take the specter of a 3 million acre-feet cut off the table. Not in the next 2 years, and certainly not over the next 10.

Like it or not, we are entering an era of maybe on the Colorado River:

As in, there may be enough water in some years to avoid catastrophes at Lake Mead and Lake Powell, and in some years, there may not.

That’s a sea change for a river that has long been treated as ol’ reliable.

And it raises more tough questions for water users than answers — including perhaps the toughest one:

Where do we find water certainty if it’s no longer in the Colorado River?


Joanna Allhands writes about water, land use and other issues important to the Arizona Farm Bureau. Reach her at joannaallhands@azfb.org.