In Arizona, worry about access to Colorado River water

TUCSON, Ariz. -- Robbie Woodhouse's grandfather began nearly a century of family farming along the Gila River near Yuma in the middle 1920s when he dug up a bunch of mesquite stumps on his land to make way for his barley, wheat, Bermuda seed, cotton and melon fields.

Farming never really took off at the Woodhouse homestead until 1954, when the federal government finished a 75-mile-long concrete canal to bring Colorado River water to what's now known as the Wellton-Mohawk Irrigation and Drainage District, which covers about 58,500 acres along the Gila River east of the Colorado.

Today, Woodhouse presides over the governing board of a district with more than 120 individual growers, partnerships, trusts and other operating entities growing about 100 different crops, including seed crops as well as staples like wheat, cotton, lettuce and other produce. Wellton-Mohawk is one of six agricultural districts in the Yuma area that together grow 90% of the cauliflower, lettuce, broccoli and other winter vegetables sold in the U.S.

But now, the future of this district, of farming in the Yuma area in general and of Arizona's second largest drinking water supply for urban residents are all mired in a sea of uncertainty. Due to a logjam in interstate negotiations for massive cuts in Colorado River water deliveries, farmers and urban users have no idea how much water use they'll be ordered to cut, possibly starting next year.

All the Yuma area irrigation districts depend entirely on Colorado River water to nourish their crops. While groundwater does lie beneath many of the farm fields, its quality is uncertain or poor in many places.

The Colorado River flows at Horseshoe Bend in Glen Canyon National Recreation Area on June 8 in Page, Arizona.Brittany Peterson ~ Associated Press, file

"Obviously we're very, very concerned," said Woodhouse, whose 1,250 acres grow mostly produce, such as cauliflower, broccoli and lettuce. "Without the water, we don't grow anything. But I wouldn't say we are scared. We do feel an obligation to do our part."

EDITOR'S NOTE: This is part of a collaborative series on the Colorado River as the 100th anniversary of the historic Colorado River Compact approaches. The Associated Press, The Colorado Sun, The Albuquerque Journal, The Salt Lake Tribune, The Arizona Daily Star and The Nevada Independent are working together to explore the pressures on the river in 2022.

Water officials of Arizona cities of Tucson, Goodyear and Scottsdale are also concerned and a little on edge although they're not panicking. They are the most dependent of Arizona cities on river water delivered through the Central Arizona Project, a $4 billion, 336-mile-long canal system running from the river to the Phoenix and Tucson areas.

While all these cities have backup supplies, led by groundwater, to cushion them in the short- to medium-term in the event of river water cuts, their long-term picture is more uncertain because the CAP was extended into Arizona nearly 40 years ago precisely to get them off groundwater.

Arizona got about 36% of its total water supply from the river as recently as 2020. That share of river water feeding farms and cities has declined some since then, with the advent of a federally approved Drought Contingency Plan that will cut the state's river water use by 21% starting in 2023. It's expected to drop even further in the coming years but nobody knows how much right now.

The uncertainty was triggered first in June, when Reclamation Commissioner Camille Touton testified at a U.S. Senate Committee hearing that to stabilize the river's declining reservoirs Lakes Mead and Powell, the basin states need to cut their water use by roughly up to 30% starting in 2023, and come up with a plan to do that by mid-August. If a plan doesn't appear by then, she warned the federal government would impose its own, to "protect the system."

But mid-August came and went with no agreement and no plan or timetable for a plan from the bureau. The bureau did say at an Aug. 16 news conference, however, that it was going to look closely at several measures such as modifying the Hoover and Glen Canyon dams so they can keep delivering water at lower elevations and counting evaporation of water from Lake Mead and the river against the Lower Basin's total water supply, thereby reducing that supply by hundreds of thousands of acre-feet a year.

So now, Wellton Mohawk and the other irrigation districts are pushing a plan to cut one acre-foot of water used per acre annually, on 925,000 acres along the Lower Colorado River in Arizona and California. In return, they're seeking $1,500 an acre-foot in compensation, or a total of $1.387 billion annually.

With that money, they'll invest in water-efficient farming tools like drip irrigation, gradually switch to less thirsty crops from water-slurping alfalfa and weather economic losses from reduced water use, Woodhouse said.

"What we want to have happen is for each individual farmer to operate their farms in the matter that they want to operate and plant the crops that they feel they can maintain the fertility of their soils," he said. "I'm sure it's going to greatly change crop rotations and also change management practices of individual farmers, to exist on less water. It's real important that those decisions be left to each individual farm."

This proposal has been roundly criticized by urban water leaders, however. While saying farms must take the biggest water use curbs because they use 72% of Arizona's water and close to 80% basin-wide, Central Arizona Project officials say the farmers' price tag is unrealistically high and that whatever money is paid should be used strictly to modernize irrigation practices for the long term.

"Anytime anyone wants to sit down with us and talk about it, we're more than willing to do so. But no one has been willing to discuss it," countered Wade Noble, an attorney representing the Yuma-area irrigation districts. "Until we get to that point, our voluntary forbearance of a significant amount of the water we control will remain on the terms we put on the table. We're not going to negotiate with ourselves."

Where both Arizona farms and cities agree is that the other river basin states and the federal government haven't moved fast enough to reduce water use.

"Reclamation has got to show some leadership and say this has got to be done and give us a guide map as to how the system is protected as the commissioner promised what it would be," Noble said.

The CAP's board president Terry Goddard and its previous president Lisa Atkins wrote a letter on Aug. 19 to Interior Secretary Deb Haaland that made essentially the same point. To date, no written response from Interior has been forthcoming.

With no action forthcoming on a deal, some Arizona water users have pulled back on past commitments to leave water in Lake Mead to prop it up. The Tucson City Council, for instance, had pledged earlier this year to leave 30,000 acre-feet in the lake in 2022 and 2023 but has since backed off that pledge and voted to order its full allocation of 144,191 acre-feet for 2023 pending the negotiations' outcome. The Gila River Indian Community withdrew an even larger commitment, to leave nearly 130,000 acre-feet in Mead next year. The CAP is holding onto 35,000 acre-feet it was going to leave in Mead and announced plans to remove another 18,000 acre-feet from the lake next year.

"Unfortunately, the community has been shocked and disappointed to see the complete lack of progress in reaching the kind of cooperative basin-wide plan necessary to save the Colorado River system," said Gila River Indian Community Chairman Stephen Roe Lewis.

Until now, it's left almost 600,000 other acre-feet of its CAP supply in Mead since 2016. In 2022 alone, CAP users and other Arizona Colorado River users left nearly 800,000 acre-feet in Mead, led by 512,000 acre-feet it legally had to leave there under the terms of the 2019 Drought Contingency Plan due to the lake's falling levels. Arizona and California left another 268,000 acre-feet in the lake this year from what's called the "500 Plus Plan," which had sought a half-million acre-feet in voluntary contributions to the lake, but projections for next year show more water will be removed from the lake under that plan than will be left in it.

Many Arizona cities using river water are preparing for the inevitability they'll have to use less. In Goodyear, in the Phoenix area's West Valley, whose population is about 101,000, the city has recharged about half of its annual CAP supplies into the ground for several years. It's also been recharging treated sewage effluent into the ground, and has stored a total of seven years' supply of both sources. It anticipates no short-term problems in delivering water to customers, said Ray Diaz, Goodyear's water resources and sustainability manager.

Colorado River shortfalls aren't going to affect what the city does now but could in the future.

"What would happen if we were shorted and had to continue our approved development?" said Diaz. "It's something we would have to look into and really assess what we could afford for the future -- how much water we can provide."

In Scottsdale in the Phoenix area's East Valley, CAP supplies about 70% of the water for its 250,000 residents. Most is delivered directly to homes and businesses rather than recharged. If the city had to sustain a large cut in CAP supplies, it would have to rely much more heavily on groundwater, said Gretchen Baumgardner, the city's water policy manager.

It has stored about 230,000 acre-feet of CAP water and treated sewage effluent in the ground -- about 2.5 years worth of its current supply -- but town officials don't want to use it all at once, Baumgardner said. It also gets about 15% of its supply from Salt and Verde River surface supplies, delivered by the quasi-public utility the Salt River Project.

"There will be a larger portion of groundwater" used in the future, said Baumgardner, adding that city officials won't know how much until they learn how drastic the cuts in CAP deliveries will be.

The city is also looking to extend its supply further. Its wastewater treatment plant in North Scottsdale operates a pilot project to treat a small amount of effluent to exceed state drinking water standards, a process called "direct potable reuse." The city is working with the State Department of Environmental Quality to help set up new state regulations that would allow the plant to reuse its wastewater for drinking on a larger scale.

But when asked if a "Day Zero" could ever arrive in which Scottsdale failed to meet all residents' demands for water, Baumgardner replied, "It's just one of those uncertainties right now. That will really be hard to answer," in part because of a pending effort by federal officials to overhaul its guidelines for operating its reservoirs -- an effort that won't be finished until 2026.

In Tucson, officials of the Tucson Water utility are more optimistic about their ability to survive major CAP cuts. The utility about 40 years ago signed up to take almost a third more CAP water than it needs today to serve the 735,610 customers living inside and outside city limits. That's allowed it to store nearly five and a half years worth of CAP in large, recharge basins -- water that can be pumped when needed during CAP shortages later. The utility also has access to a huge aquifer lying under a large expanse of former farmland northwest of the city that it bought and retired in the 1970s. It also is regularly recharging and storing underground large amounts of partially treated effluent that can be pumped later for drinking.

But there is one cautionary note. A recent Bureau of Reclamation study found that as the Southwest's climate warms up, runoff of melting snows into rivers and washes surrounding the city is likely to decline, meaning less water will be replenishing its aquifer than in the past. That would increase the possibility that groundwater pumping in place of CAP water use could put increased pressure on the aquifer, triggering higher pumping costs and more likelihood of subsidence in which the ground collapses, possibly triggering fissures.

Ultimately, the story of CAP water in Arizona is a story about groundwater, added Kathryn Sorensen, a researcher for Arizona State University's Kyl Center for Water Policy. When there's less Colorado River water delivered to Arizona, the cities, farms and other users fall back on groundwater, she said.

"We are very blessed to have plentiful aquifers in central Arizona we can fall back on," Sorensen said while noting they are fossil aquifers, meaning water entered them thousands of years ago and they are not easily replaced.

"If we pump them and are unable to replenish the pumping, the aquifers will pay the price," she said.