There is no easy or painless way to solve Willcox’s groundwater problems.

At least 150,000 acre-feet more water flows out of the southeastern Arizona basin than flows into it each year, according to state estimates.

This decline has accelerated since 1990, drying up wells, cracking the earth and permanently damaging the aquifer’s capacity to store water. 

To cut that figure in half — a goal the Department of Water Resources has proposed for the basin — farmers could be required to slash use by roughly 75,000 acre-feet* by 2075.

(Yes, the asterisk is on purpose. We’ll get to that.)

Groundwater is all there is

Willcox is among the nation’s largest producers of pecans and pistachios.

It grows most of the state’s wine grapes, as well as alfalfa for local dairies and a smattering of other crops.

Fields here average some of the highest irrigation efficiency rates in the state. 

But crops require steady water to grow. And groundwater is all there is. 

Mountain runoff doesn’t recharge the aquifer much, and there are no real prospects to recycle or import water.

Not in the quantities necessary to meaningfully offset pumping, at least.

Farmers know something must give. They can’t afford to deepen wells and remain economically viable forever.

“Subsidence will crush a well casing like you stepping on an aluminum can,” said Tedd Haas, a Cochise County Farm Bureau board member who grows multiple crops on the northern end of the Willcox basin.

“It’s expensive. And it happens unexpectedly, like a heart attack, usually in the middle of the season when we really need water.”

Water cuts require careful balance

Many like Haas say they are willing to cut water use, particularly if it can help sustain their operations for the next generation.

But cutting water allotments too deeply could idle major chunks of land, upending a local economy that depends on agriculture.

This requires careful balance.

Which brings us back to that asterisk.

It’s unclear, for now, exactly how much water must be cut to meet Willcox’s proposed 50% overdraft reduction goal.

Presuming the goal is adopted, reduction targets won’t be set until next year, after the state has collected more data to more confidently say how much water is being removed from the aquifer.

But the Department of Water Resources doesn’t want to wait until later management plans to start trimming agricultural water use.

A draft of the basin’s first management plan includes a 10% cut in water duties — the maximum amount of water that farmers can pump in a year — for nearly all crops, right out of the gate. 

That has never been done before.

Arizona tries a new approach

In Phoenix and Tucson, where the management goal is more stringent — essentially zero overdraft, as opposed to a 50% reduction in Willcox — water duties were not cut in the first management plan.

Later plans focused heavily on efficiency gains for farmers, not straight cuts to their water allotments.

But those urban basins had access to other water sources.

And they experienced steady growth that replaced farms with houses, cutting agricultural water use over time.

With those options effectively off the table in Willcox — and other overdrawn basins where agriculture drives nearly all water use — the department says it must take another tack.

The proposed management goal for the Ranegras Plain in western Arizona is similar to Willcox’s, though the state has only just begun work on its management plan.

“We are trying to be very thoughtful, knowing that we’re asking people to do a very difficult thing,” said Olga Hart, who is overseeing the regulatory rollout in both basins.

How do we get water duties right?

A lot rides on where Willcox’s initial water duties are set, particularly if state water officials intend to cut them more deeply in subsequent management plans. 

Arizona Farm Bureau has questioned whether the department has legal authority to make those cuts. 

State law says water duties must be calculated as “the quantity of water reasonably required to irrigate the crops historically grown in the farm unit.”

A key part of the answer is how much water crops need not just to stay alive, but to produce a healthy yield.

University of Arizona agronomist Jeff Silvertooth has spent much of his career researching this question. He and colleague Randy Norton have taken a deeper drive into water allotment calculations after farmers contacted Silvertooth with questions.

They found, for example, that corn grown in Willcox requires differing amounts of water, depending on whether it is grown for grain or silage. 

The same goes for perennial crops such as hesperaloe that require little water when mature but a lot more while establishing their roots.

Silvertooth said officials have been receptive to feedback about these and other major crops grown in the basin.

Reaction in Willcox is mixed

Haas, who has long advocated for additional regulation and serves on the basin’s groundwater advisory board, agreed.

State water officials had the difficult task of balancing those who wanted faster and more stringent cuts with those who wanted few or no changes.

“They created a measured plan,” he said. “It’s setting a tone, one that I think will allow us to continue farming but also start looking at alternate cropping patterns and more intensive irrigation management.”

David Collins, who serves with Haas on the Cochise County Farm Bureau board, is more skeptical that the plan will save water over time because of how efficient farmers already are.

“A 50% cut will hurt no matter what the initial duties come in at,” he said. “But that’s also 50 years down the road, and who knows what the later revisions will look like.”

Collins opposed regulation initially because voters had previously rejected the question.

“That’s beside the point,” he said. “It’s here now. We’ve just got to take it and try to work with it.”

---

What’s next?

The Arizona Department of Water Resources plans to finalize Willcox’s first management plan later this year, with provisions taking effect in 2029.


Joanna Allhands writes about water, land use and other issues important to the Arizona Farm Bureau. Reach her at joannaallhands@azfb.org.