Happy New Year!

Think I’m being premature? Think again.

October 1 marked the beginning of the new water year — sort of like a fiscal year for water managers.

But while there might be occasion for a stiff drink, few will be popping bottles of champagne, as the new water year also reveals how the big users of the Central Arizona Project will handle major cuts to Arizona’s supply of Colorado River water.

For Tucson, that means crossing a Rubicon, so to speak.

Tucson is giving up about half of its usual Colorado River allocation of 144,191 acre-feet per year. This water year, only 71,000 acre-feet of new wet water will be coming into the system, per a CAP contract approved by the council last month.

However, Tucson Water will also receive between roughly 20,000 and 28,000 acre-feet from the Arizona Water Banking Authority to compensate for part of those cuts, meaning that Tucson Water’s total allocation next year is in the 90,000+ acre-feet range. This water already sits in Tucson’s own water banking system, so the compensation represents a legal transfer of paper water.

What does paper water mean? And why are we putting some words in bold in today’s newsletter?

Because we’ve got another edition of our Water Glossary, which we introduced last month to help regular people break through the jargon of Arizona’s water world.

Auld Lang Syne

The first of October marks the beginning of a new “water year.” For those who measure and study water, it is a demarcation that allows for an accurate picture of snowmelt and other forms of precipitation in the coming seasons — early fall is generally when streamflows are low and aquifer levels stable.

For those in charge of managing water systems, particularly in central Arizona, it functions much like a fiscal year: Users place an order for water from the Central Arizona Project and the federal government based on their system’s needs over the coming year and any voluntary or mandatory cuts.

For the most part, these users don’t themselves divert water from the main stem of the river. Instead, they enter into contracts for specific volumes of water with the Central Arizona Water Conservation District (which, broadly speaking, runs CAP) and the federal government (which, broadly speaking, paid for CAP).

CAP itself holds a contract with the federal government, hence the term CAP subcontractor.

You can check out a 2025 list of subcontractors and their entitlements here.

Solid, paper, liquid, vapor

You’ll often hear water wonks talk about “wet” and “paper” water.

Perhaps you thought that, even in Arizona, all water was wet.

Not so, depending on how you think of it.

Generally, wet water means actual water that sits in a river, canal, aquifer or reservoir. Paper water refers to a legal water right that may or may not be directly connected to actual water — think long-term storage credits.

One issue is it’s not always so simple to turn those paper rights into real water, whether because of infrastructure or law. And they can obscure how much actual water is in the system. But they also effectively tape the system together.

That’s probably enough glossary items for the moment. Let’s get back to what the city council is doing...

That 90,000+ acre-feet sum for the upcoming water year is plenty to meet the city’s needs, Kmiec said at the meeting last week.

In an exchange that seemed more intended for the viewing public (if such a public exists during a midday study session) than for anyone on the council, Mayor Regina Romero asked Kmiec if he feels confident that amount “is sufficient to be able to provide the water services for all of our customers, including commercial, residential, industrial?”

And indeed, Romero wants to reassure Tucsonans that their water supply is secure.

This came up during debates on Tucson’s large water ordinance last month, when Romero said at one point that concerns about the city’s water supply might be getting in the way of economic development.

So the city is also planning a series of town hall meetings to spread the gospel of conservation, to tout the city’s international reputation as a smart water user and, basically, to assure people that water will still be coming out of their taps.

Still, that doesn’t mean Tucson isn’t sacrificing to keep up with the dry times. Here’s how the cuts are broken down:

As for Tucson’s liquidity, to turn a phrase, most of this compensation cash is set aside for other water conservation and augmentation projects, so don’t expect it to patch any holes in the city general fund.

Still, that’s money that will help the city weather the continuing “mega-drought” that has settled over the region — and any future federal cuts that might entail.

Tucson has already taken cuts under the Drought Contingency Plan, and while city staff is planning revisions to the city’s drought response next calendar year, the city will remain under the same drought response conditions for now. That means, per city documents, “leading by example and encouraging customers exceeding their water use guidelines to take action and use water more efficiently.”

In other words, most of you can rest assured that although there is a historic drought, the city is not yet requiring you to change your behavior. But it would sure be nice. Happy New Year!

If you’ve followed our coverage of the Colorado River situation, you may be wondering how the much-vaunted shortage sharing agreement between the three Lower Basin states of Arizona, California and Nevada factors into this new water year.

This agreement — in theory — will allow Arizona to take smaller reductions in 2027 and 2028 than it would in a scenario where the feds imposed 3 million acre-feet a year in cuts on the Lower Basin, as indeed could happen.

The federal plan for the river leaves room to revise cuts based on the agreement. But, as we’ve noted before, the three-state deal hasn’t actually been signed yet.

A spokesperson for the Arizona Department of Water Resources said that since the current raft of Colorado River agreements doesn’t expire until the end of the calendar year, there’s still time to work out some kinks in the Lower Basin deal. (Remember also that Nevada is suing the federal government over its river plan.)

Nevertheless, he emphasized that all three states were in agreement on the broad strokes of the plan.