Water officials share grim outlook for CAP water supply

A year ago, in discussing an impending, first mandatory cutback in Central Arizona Project deliveries, CAP and state water officials emphasized that they amounted to “planned pain,” having been in the works under a 2019 drought plan.

While acknowledging the shortage then already expected for 2022 would cause hardship, particularly to Pinal County, Arizona Department of Water Resources Director Tom Buschatzke said that didn’t show that the Drought Contingency Plan requiring them was a failure.

“DCP was not meant to eliminate the chance of shortage at all. A shortage does not reflect the failure of DCP. It is a success,” said Buschatzke, using a common abbreviation for the drought plan.

Last Friday, the official mood was much more somber at the latest state-CAP briefing on shortages, held at CAP’s Phoenix office. Buschatzke and CAP General Manager Ted Cooke made it clear they expect more severe shortages than this year’s as soon as next year. And bigger cuts would likely come in the years beyond. They talked repeatedly of the need for Arizona cities to start making plans to use less water, led by cuts in outdoor watering.

But Cooke added, “We have no need to panic. There’s no imminent threat to water at the tap.”

A federal official, Dan Bunk of the U.S. Bureau of Reclamation, said at the briefing there’s a possibility that as soon as 2024, the Lower Basin will suffer its most severe shortage planned by the 2019 drought blueprint — one that would for the first time cut CAP deliveries to Tucson.

A big difference between now and a year ago is that conditions on the river and at its big reservoirs continue deteriorating faster than had been expected by federal forecasters back then. Lake Mead’s water level has dropped 22 feet to about 1,053 feet since April 2021 — nearly 12 feet lower than forecasters predicted a year ago. Lake Powell has fallen 40 feet to about 3,522 feet in the same period, nearly 20 feet lower than predicted a year ago.

Last Tuesday, the Interior Department announced it will hold back 480,000 acre-feet of water — almost five years worth of Tucson’s drinking water demands — in Powell this year that it had previously planned to release to Mead. Mead, at the Nevada border, stores water for CAP deliveries.

Conservation essential

That cut won’t translate to immediate reductions in water deliveries to Arizona and other Lower Basin users due to an agreement between states and the feds to make the impact “operationally neutral.” But it has sparked fears in many water users of more serious consequences if it’s repeated in future years.

Without that cut, Powell could possibly have fallen next year or maybe even in late 2022 to below 3,490 feet, and stayed there all next year if another dry year occurs, bureau hydrologist Bunk told Friday’s briefing. That’s the minimum elevation required for the adjoining Glen Canyon Dam to generate electricity for 5 million, mostly rural customers in Arizona and five other Western states.

While not specifying what cuts local governments should do now, Buschatzke and Cook said additional conservation was essential to keep Arizona from following the footsteps of California. In March, that state’s governor, Gavin Newsom, issued an executive order that will lead to mandatory cuts of up to 20% by many cities statewide this summer. Last month, Southern California’s Metropolitan Water District ordered about 6 million residents there to limit outdoor watering to one day a week. The cuts follow a dramatic reduction in deliveries this year through the State Water Project canal system running from Northern California to the Los Angeles area.

People in the worst hit areas of Southern California will have to live on 50 gallons per person per day, the Arizona officials said. That compares to 119 gallons per person daily that Tucson Water reported to ADWR that its 743,000 customers consumed in 2020.

“We don’t want to be living on unhealthy allocations in our state. We may be in that place in the future but we’re going to do everything we can to avoid that outcome,” Buschatzke said.

Bunk told the briefing that while winter snowpack conditions in the Upper Basin were about 90% of normal levels in 2021 and 2022, the 2021, spring-summer runoff into Powell was only 32% of average levels. This year, the latest projection, for 59% of average runoff, was announced last week by the federal Colorado Basin River Forecast Center.

“We do seem to be getting precipitation, but warmer temperatures, dry soil conditions and increased evapotranspiration seem to be conspiring to some extent against us,” Bunk said.

A letter to the seven river basin states last Tuesday from Assistant Interior Secretary Tanya Trujillo announcing the cut in Powell’s release is consistent with what the states had previously requested, said Buschatzke, adding, “It’s absolutely necessary for all the reasons already discussed.”

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In its most recent forecast last month, the bureau predicted Mead will drop below 1,050 feet elevation by the end of 2022. If that prediction holds, Arizona would lose 80,000 acre-feet more of water in shortages on top of the 512,000 that were cut this year.

CAP’s Cooke said there’s a chance Mead will fall below 1,045 feet by the end of 2022, cutting another 48,000 acre-feet from Arizona’s river supplies, although he said that’s unlikely. At below 1,045, California would also have to take cuts — its first under the 2019 drought contingency plan.

They also spoke bluntly of the possibility of Mead falling below 1,025 feet in the coming years, a level once considered unthinkable. At that point, Arizona would hit its peak, planned shortage level, called Tier 3, cutting 720,000 acre-feet a year from their CAP supplies.

‘This is our future’

Under Tier 3, Phoenix-area cities and tribes would for the first time lose some of their highest priority supplies, and Tucson, would lose about 14% of its annual CAP share of 144,000 acre-feet a year. Also, once such a shortage is declared, state officials and the Interior Secretary’s office will consult about increasing shortage levels “to protect Lake Mead,” Buschatzke said.

“Again, that’s part of the uncertainty we’re facing. The gravity of the immediate situation is serious,” Buschatzke said.

He and Cooke noted that in the early years of CAP shortages, water users will get mitigation, either in water stored underground years ago to prepare for such occurrences, or money. Eventually, the extra water and money will go away, they said.

A Tier 3 shortage declaration for 2024, while possible, is less likely than the Lower Basin staying at Tier 2, said Bunk.

At one point during the briefing, a Tohono O’Odham tribal representative asked, “How are we insuring that future declarations of shortages don’t affect water delivery to tribes?”

Buschatzke replied: “There’s no guarantee of any water supplies. If we cannot resolve issues to move water through the dams, we can get to the point where the highest priority rights are impacted.

“Not receiving 480,000 acre-feet is a big step, to avoid the likelihood of the highest priority users getting cut to the bone,” he added.

Buschatzke and Cooke also emphasized Arizona’s conservation successes. The state has saved 812,000 acre-feet a year through various programs, including the 2019 drought plan, and a more recent plan to save at least 500,000 acre-feet a year over the entire Lower Basin in 2022 and 2023.

“We’re conserving one fourth of the state’s total apportionment of Colorado River water,” said Buschatzke. “This is our future.”

To respond to the bad river conditions, under the 1980 ,Management Act, management plans that ADWR issues to set more general conservation requirements for urban areas such as Tucson and Phoenix could be tightened up. A fifth such set of management plans is now pending in various water management areas including Tucson, but Buschatzke said he did not see the need to toughen them now.

“The current draft management plans were certainly developed in full knowledge of the challenges facing the Colorado River,” he said. “Those plans accomplish the statutory goal of decreasing groundwater use. Those plans are robust. They do what is legally required.”

Looking further ahead, the director said Arizona and other basin states will be planning in the future to set a long-term target for what they expect total annual river flows — one much less than the roughly 14 million acre-feet a year the Upper and Lower Colorado River Basins now use.