Robbie Woodhouse’s grandfather began nearly a century of family farming along the Gila River near Yuma in the mid-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 such as wheat, cotton, lettuce and other produce. Wellton-Mohawk is one of six irrigation 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 — the Colorado River — are all mired in 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 will be ordered to cut or when cuts would occur.
All Yuma area irrigation districts depend entirely on Colorado River water to nourish crops. Groundwater lying beneath many of the farm fields is of uncertain or poor quality.
Woodhouse’s 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,” he said. “We do feel an obligation to do our part.”
Water officials of Arizona cities of Tucson, Goodyear and Scottsdale are also concerned but not panicking. They are the most dependent of Arizona cities on Colorado River water delivered through the Central Arizona Project, a $4 billion, 336-mile-long canal system from the river to the Phoenix and Tucson areas.
Backup supplies are led by groundwater
While these cities have backup supplies, led by groundwater, to cushion them in the short to medium term, their long-term picture is more uncertain because the CAP was extended into Arizona nearly 40 years ago 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.
Uncertainty was triggered first in June, when Reclamation Commissioner Camille Touton told a U.S. Senate Committee that to stabilize the river’s declining reservoirs Lakes Mead and Powell, river basin states needed to come up with a plan by mid-August this year to cut water use by up to 30% starting in 2023. If a plan didn’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 of Reclamation. Bureau officials said at an Aug. 16 news conference, however, that they will look closely at several measures such as modifying the Hoover and Glen Canyon dams so they can deliver water at lower elevations; and counting evaporation of river and reservoir water against the Lower Basin’s total water supply, thereby reducing that supply by hundreds of thousands of acre-feet a year.
Federal government’s pace criticized
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 want $1,500 an acre-foot in compensation, or a total of $1.387 billion annually. An acre-foot is enough to serve two to four Arizona households for a year.
With that money, the districts would 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. That will likely involve crop rotations and other changes, he said.
The proposal has been roundly criticized by urban water leaders. While saying farms must take the biggest water use curbs because they use 72% of Arizona’s water and close to 80% basinwide, CAP officials say the farmers’ price tag is unrealistically high and that money paid should be used strictly to modernize irrigation practices.
Where Arizona farmers and city officials agree is that the federal government has not 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 it would be,” said Wade Noble, an attorney representing the Yuma-area irrigation districts.
The CAP’s board president Terry Goddard and its previous president Lisa Atkins wrote a letter on Aug. 19 to the Interior secretary that made essentially the same point. To date, Interior hasn’t responded.
Now, some Arizona water users have pulled back on past commitments to leave water in Lake Mead to prop it up.
Those users include the Central Arizona Project itself, the city of Tucson and the Gila River Indian Community. They’ve at least temporarily withdrawn commitments to leave nearly 250,000 acre-feet in Mead this year and next. That’s almost as much river water as Robbie Woodhouse’s Wellton-Mohawk Irrigation District sprays on its crops in a 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, the Gilas have left almost 600,000 other acre-feet of their 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 the CAP had to leave there under the 2019 Drought Contingency Plan due to the lake’s falling levels.
That compares to a total of 1.062 million acre-feet CAP is expected to deliver to all of its customers during 2022.
Arizona and California left another 268,000 acre-feet in the lake this year from 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.
Cities face inevitability
Many Arizona cities using river water are preparing for the inevitability they’ll have to use less river water.
Officials of Tucson Water are optimistic about the city’s ability to survive major CAP cuts, although they know that at some point they’ll likely be pumping groundwater in its place.
About 40 years ago, the utility signed up to take almost a third more CAP water than it needs today to serve its 735,610 customers living inside and outside city limits. That’s allowed it to store nearly five and one-half years worth of CAP water in large recharge basins — water that can be pumped when needed during CAP shortages later.
Tucson Water also has access to a huge, largely untapped aquifer lying under a large expanse of former farmland northwest of the city that it bought and retired in the 1970s. It also regularly recharges, and stores underground, large amounts of partially treated effluent that can be pumped later, and is slowly moving into a program to build “green infrastructure” such as rainwater capture facilities, using a small fee charged to water customers.
“We’re still awaiting to see what the CAP cuts will be. We have been prepared for it. We have a diverse portfolio” of water sources, said Tucson Water Director John Kmiec. “We have multiple dials, multiple water resources.”
But there is a cautionary note. A recent Bureau of Reclamation study found that as the Southwest’s climate warms, runoff of melting snows into rivers and washes surrounding Tucson 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.
On one level, Lisa Shipek of Tucson’s Citizens Water Advisory Committee agrees with Kmiec — that the city can survive with less or even no CAP water. Fulltime director of the nonprofit Watershed Management Group, Shipek endorses what she calls a “hydrolocal approach,” one that would rely much more heavily on using captured stormwater and recycled sewage effluent.
She favors measures to reduce Tucson Water’s per-person water use from 80 gallons to 40 gallons a day, to take pressure off underground aquifers and trigger recovery of rivers and streams that dried up 70 years or more ago.
Her ideas for achieving that goal include banning decorative, “nonfunctional” turf for homes and businesses, starting with new development and eventually phasing it in on existing development. She also suggests rebates for low-flow appliances and for rainwater harvesting and gray water equipment to homeowners living outside Tucson Water’s service area. She also favors putting more restrictive measures in the city’s drought plans, to kick in when CAP shortages get worse, and to also tie the drought plans to local water conditions such as aquifer levels as well as to conditions on the Colorado River.
“We want to live in a community where we have a place where we feel we can live here in the summer,” Shipek said. “We want to have an urban forest, flowing rivers, that has a certain quality of living. That’s what we love about the Sonoran Desert. We should be using every tool in our toolbox to drive down water use, maximizing recharge, to continue to bring our groundwater levels up, to support streams, creeks and rivers.”
Phoenix-area cities’ plans
In Goodyear, in the Phoenix area’s West Valley, population about 101,000, the city has recharged about half of its annual CAP supplies into the ground for several years. It’s recharging treated sewage effluent into the ground, and storing 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.
The cutbacks could, however, affect the city’s ability to serve and allow continued growth, he said. Under that circumstance, the city would have to assess what it can afford in the way of future growth and water deliveries, he said.
In Scottsdale east of Phoenix, CAP supplies about 70% of the water for its 250,000 residents. Most is delivered directly to homes and businesses. If Scottsdale sustained a large cut in CAP supplies, it would have to rely much more heavily on groundwater, although it doesn’t know how much now, said Gretchen Baumgardner, the city’s water policy manager.
Scottsdale 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 city officials don’t want to use it all at once, Baumgardner said. It also gets about 15% of its water supply from the Salt and Verde rivers.
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 Arizona Department of Environmental Quality to help set up new regulations to allow the plant to treat 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 guidelines for operating reservoirs. It won’t be finished until 2026.
Ultimately, the story of CAP water in Arizona is a story about groundwater, said Kathryn Sorensen, a researcher for Arizona State University’s Kyl Center for Water Policy. When less river water is delivered, cities and farms fall back on groundwater.
“We are very blessed to have plentiful aquifers in central Arizona we can fall back on,” Sorensen said. “But they are all fossil aquifers,” whose water entered them thousands of years ago and can’t be easily replaced.
“If we pump them and are unable to replenish the pumping, the aquifers will pay the price.”
Arizona water chief seeks federal action on Colorado RiverFor Star subscribers: Compensated turf removal; paying farmers to grow lower-water-use crops; and investing in water reuse, recycling and salt water desalination are among the dozen specific proposals.
For Star subscribers: Arizona and California, which have battled over the Colorado River for nearly a century, are at it again. This time, Arizona leaders are blaming California, and other states, for putting the burden of stemming the river's impending crisis on their backs alone.
