Arizona may give up even more Colorado River water

• Three states trying to avoid future federal takeover of water allocation
• Without cuts, Arizona could be left without access to the reservoir
• California would forfeit some of its share under proposed agreement

Recent negotiations could lead to bigger water cuts for Arizona and Nevada if a shortage is declared on the Colorado River.

The emerging proposal could also put California on the hook to cut some of its share if shortage conditions were to worsen.

Water-policy leaders from basin states have met regularly since last summer to discuss ways to avoid draining Lake Mead to the point of federal takeover.

The U.S. Department of the Interior would take charge of water allocation if the reservoir's elevation were to sink to 1,025 feet. That could leave the Central Arizona Project without access, based on its junior rights to the river. But that’s up to the discretion of the Interior, said Theodore Cooke, general manager at the Central Arizona Project.

Cooke said water-policy leaders are considering a solution that cuts the risk of hitting that point by about half.

Lake Mead stood above 1,077 feet in elevation Monday. But water managers predict that a shortage is increasingly likely in the coming years. The U.S. Bureau of Reclamation would announce a shortage during the summer if it projects Lake Mead's elevation would sink to 1,075 feet or lower at the beginning of the following year.

MAP:Tracing the path of the Colorado River

FULL COVERAGE:As the River Runs Dry

Representatives from both Nevada and California said it was too soon to talk specifics, but the Arizona Department of Water Resources reviewed the plan with the Southern Arizona Water Users Association last week.

That presentation included the following cuts:

• Arizona would lose 512,000 acre-feet of its share if a first-level shortage is declared, compared with the 320,000 acre-feet it had agreed to cut based on 2007 negotiations
• Nevada would sacrifice 21,000 acre-feet, up from its original 13,000.
• Both Arizona and Nevada would take reductions even without a shortage, but Cooke pointed out that Arizona has already been conserving a comparable amount so this would not affect a major change here. Nevada also has been conserving water in Lake Mead through that same agreement.
• The Bureau of Reclamation, which manages Lake Mead, would find ways to save 100,000 acre-feet per year.
• California would take a cut of 200,000 acre-feet but only if the shortage worsened. At that point, Arizona would have to give up much more.

To put that into perspective, an acre-foot — 325,851 gallons — is about what two Arizona households use in a year.

Tanya Trujillo, executive director of the Colorado River Board of California, said the group has been walking through a "hypothetical scenario" and that they haven't reached agreement on specific details.

“It’s really premature to discuss specific details, but we’re continuing to work in good faith. We are looking for an agreement that will be beneficial to all three Lower Basin states,” Trujillo said. “There are still significant issues that we need to keep working through. So we’re going to keep at it, and it may take several months. It may take another year.”

In Arizona, exactly how those hypothetical cuts would be absorbed is yet to be determined. Agricultural customers, who have expected to take the biggest hit during a shortage, will likely not be alone. The state will ask cities and towns to volunteer to offset the burden, Cooke said.

Some cities are already making sacrifices. Phoenix, for example, is tapping into banked water to offset some of its usual consumption directly from the Colorado River. “Our hope is that we have some sharing of the burden so it doesn’t just fall on the backs of some,” Cooke said.

Residents have not felt the effects, as the city only uses about two-thirds of its allotted water.

That, along with other conservation efforts around the state, is helping the CAP leave a portion of Arizona’s share in Lake Mead to stave off a shortage. The move was part of a 2014 agreement among Colorado River users to conserve up to 740,000 acre-feet in Lake Mead by 2017.

Lake Mead hit record lows last summer, but a wet spring in conjunction with the 2014 agreement helped to stave off a shortage, Cooke said.

February's heat increases chance of 2018 Lake Mead shortage

Regardless of the ongoing drought, lower-basin states consume more water from the river than what it provides.

They have been draining Lake Mead since river allocations were made in the early 1900s because the deal never took into account vast amounts of water lost to evaporation or the moving process.

That reality hasn’t thrown us into shortages before because the upper basin hasn’t used its full allocation for years, which has allowed excess water from Lake Powell to flow into Lake Mead.

The two lakes can store up to four times the normal flow of the river. That storage has held us over through dry years, said Chuck Cullom, Colorado River programs manager for the Central Arizona Project.

Water managers have been working through more long-term solutions for years, as residents in major cities have made significant cutbacks at home.

Arizona Department of Water Resources Director Tom Buschatzke called recent negotiations a landmark because California is willing to take less than its legal entitlement and Arizona is willing to take bigger cuts than what it agreed to in 2007.

"Voluntary participation by all three states would create certainty that would allow each state to control its own destiny," Buschatzke said.

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Reporter Ian James from the Desert Sun contributed to this article.