For two of the Tucson area’s biggest suburban water users, the impact of Central Arizona Project shortages is all about the long term.
Officials of Farmers Investment Co., which grows pecans in Sahuarita, and Freeport McMoRan, which runs a major copper mine in the Green Valley area, say they are not concerned about shortages on the scale likely to befall the CAP in the next few years.
But they are concerned about the effects of shortages should the current drought last a long time — which is what many scientists are forecasting.
FICO’s pecan groves now get about 40% of their water from CAP supplies owned by Freeport and Tucson Water. They might at some point have to replace at least some of that with the groundwater pumping that CAP was brought in to replace.
In addition, Dick Walden, FICO’s president and CEO, said he believes this region will need to eventually bring in additional water supplies, possibly by building a desalination plant for seawater or brackish groundwater, to counteract impacts of increasingly arid weather and accelerating population growth.
Brackish water, found in groundwater in parts of western and west-central Arizona, has more salts and other dissolved solids than fresh drinking water but less than seawater.
“We also need to leverage technology to use water more efficiently, as we are doing here on the farm,” Walden said. “Hopefully, more efficient water consumption and use of renewable water will get us through this challenging period.”
Both companies have invested heavily in bringing CAP’s Colorado River water to Southern Arizona.
FICO and Freeport last year jointly finished work on a $17.1 million project to build a series of CAP-bearing pipelines, totaling 11 miles, to take the water to FICO’s pecan groves in the Sahuarita-Green Valley area.
Freeport supplies 65% of the 10,000 acre-feet of CAP water that’s now used on the pecan groves and paid $11.2 million for construction. FICO supplied the balance of the construction tab.
The remaining CAP water used at the groves is owned by Tucson Water.
In all, Freeport says it imports about 30,000 to 50,000 acre-feet of CAP a year to the Phoenix and Tucson areas. The company exchanges the CAP water, besides what’s used on the pecan groves, with other users for the rights to groundwater lying closer to its mines in the Green Valley area and in Gila County’s Miami.
Freeport leases 22,000 acre feet of CAP water from the Gila River Indian Community that is being stored at other farms around the state, which the state recognizes as “groundwater savings facilities.”
Able to pump elsewhere
Putting that CAP water onto the farms allows Freeport to do future exchanges of that water for other groundwater, or to gain long-term credits from the stored CAP that allow Freeport to pump groundwater elsewhere, including at its Sierrita Mine just west of Green Valley.
The credits are granted by the Arizona Department of Water Resources, which regulates groundwater pumping under a 1980 state law calling for an end to over-pumping of aquifers in the Tucson area and other urban areas by 2025. These credits provide legal compensation for the groundwater pumped elsewhere, and Tucson Water gets similar credits for the CAP water it uses to irrigate the groves.
Between them, the pecan groves and the Sierrita Mine use 48,000 to 51,000 acre-feet a year. That’s equivalent to about half of what the 739,000 people served by Tucson Water use each year.
No immediate cuts
When shortages occur, both Freeport’s and Tucson Water’s CAP supplies being used at the groves won’t be affected for at least the first two years because that water has a higher priority than the CAP water that will be cut at first.
Those first-round cuts, likely to begin next year, will fall largely on Pinal County farms.
Under the complex system that state and federal officials have established to manage potential future cuts in CAP deliveries, CAP users with a lower priority will get their supplies reduced or eliminated before those with a higher priority.
The water irrigating the pecan groves south of Tucson in Pima County is a mix of two different types of CAP supplies that have higher priorities than the Pinal farmers, so will be be cut off at later stages of shortages.
Starting in 2023, some of the CAP water belonging to Freeport that is used at the pecan groves could start being cut. At first, the cuts will be “mitigated” by other water supplied by the state and the CAP’s operators.
2026 to be a key year
By 2026, assuming shortages continue through then, no more mitigation will occur. But Freeport even then could make use of credits it gets from other CAP supplies that it has stored elsewhere for many years, said Linda Hayes, a Freeport spokeswoman.
Also, when no more mitigation water is available, Freeport could send some of the CAP water it leases from the Gila River tribe to the groves, if some of the supplies now being used for the pecan trees are reduced, Hayes said.
But starting in 2026, if levels at Colorado River reservoir Lake Mead continue to fall, CAP could suffer a more severe shortage that would start to cut some of even the top priority project water now being placed at the pecan groves.
Hopes for new technologies
Walden said he hopes that as clean water becomes more scarce and expensive, the market will develop new technologies to use water more efficiently and clean it more effectively.
He cited desalination of brackish groundwater and recycling of wastewater for human consumption as possible examples.
“Other countries such as Israel, Australian and Switzerland, and even (California’s) Orange County are leaders in developing state-of-the-art purification techniques that make water fit for human consumption that would otherwise go to waste. Desalinization has come a long way as well, especially with brackish as opposed to ocean salt water,” Walden said.
FICO officials are “proud of the fact that we’ve been able to be helpful in reducing our groundwater use through the waterline, and will continue to do so by farming in the most efficient way possible,” Walden said.
If the current drought persists, “we’ll respond by using the water available to us in the future, be it reclaimed water, groundwater, reduced deliveries of CAP water, or some combination thereof,” he said.
Climate change analysis
Freeport’s Hayes added: “A sustained drought for longer periods is a concern. We know that climate change is expected to exacerbate drought conditions.”
To deal with that and other potential climate-related risks across Freeport’s entire business, the company has started work on “a robust and comprehensive climate change scenario analysis,” with help from an outside consultant, Hayes said.
The analysis will identify potential climate-related risks and opportunities, including those involving water, stretching to 2050, Hayes said.
Freeport will also study opportunities to enhance its resilience and that of nearby local communities. The company expects to provide more information about its findings and recommendations later this year.
In addition, the mining company has taken significant steps to switch to as much renewable, recycled, low quality and reused water as possible, Hayes said. It continues to evaluate additional water reuse and recycling options and improve water efficiencies at all operations, she added.
“Company-wide, we used four times more recycled water than new water in 2019, achieving a water-use efficiency rate of 87%,” Hayes said.