Brandon Loomis

The Republic | azcentral.com

YUMA –Smoke rising from groves of lemon trees offers one dramatic visual clue to Arizona's increasingly complex water future: Groves here are going fallow, for a price, to test how much moisture farmers could spare for urban development.

In an era when persistent drought is shrinking Lake Mead, the great Colorado River reservoir, and the entire Southwest is seeking replacement sources, public water managers are pointing their divining rods at farms.

To date, the idea of tapping Yuma agriculture to supply suburban sprinklers around Phoenix is just a pilot project, to determine how much water can be saved; any attempt to start water actually flowing to central Arizona will require costly leases with willing sellers.

But if the state continues to grow while, as government scientists predict, climate change continues to shrink the Colorado River, something has to give. Some of this region's farms are likely to prime the pump for profit.

That's why workers for 33 Yuma farmers started cutting, stacking and burning lemon trees across 1,400 acres of the Yuma Mesa Irrigation and Drainage District last spring, turning orchards into fallow land and saving water.

"It gives the farmer a stable income source where it's not tied to the market," irrigation district manager Pat Morgan said.

Mostly, though, it gives the Central Arizona Groundwater Replenishment District a tantalizing option to replace at least some of the pumped groundwater used in hundreds of thousands of central Arizona homes and yards.

These homes are served by water suppliers counting on the groundwater district to find and buy water to replace what they use. The district, governed by the same board that pumps Colorado River water to cities in the Central ­Arizona Project canal, is required by state law to do so, and to charge the users for it.

The district has contracts with utilities that supply about 43 percent of the people in Maricopa, Pinal and Pima counties. Another 126,000 homeowners who rely more heavily on groundwater pay property taxes directly to the district to replenish it.

It's a complicated and costly workaround for suburban developers, who were initially restrained by a 1980 groundwater-protection law.

To build homes whose occupants would consume groundwater, according to that law, developers had to prove they could tap a 100-year supply. But 13 years later, the Legislature decided any developments that joined the district could proceed to build without an assured supply, and the district would go find the water to sink back in the aquifers that served them.

For many years, the job has been as simple as slurping up and dumping the excess Colorado River water that cities like Phoenix had contracted but weren't yet using from the Central Arizona Project. But after nearly 15 years of drought have steadily shrunk Lake Mead's pool, "excess" and "Colorado River" are hardly compatible terms.

The groundwater district is coming for a new dip into the river at exactly the time that other users fear the competition. Cities, including Phoenix, Mesa and Tempe, in the Arizona Municipal Water Users Association use CAP water directly instead of as an aquifer recharge.

"There's a lot of competition. There are shortages on the river that we're trying to deal with," association Executive Director Kathleen Ferris said.

"There is continuing concern within (the municipal suppliers) that this paradigm of allowing growth to proceed before water is in hand is not sustainable."

Growing need

The federal government has warned that continued drought and depletion of the reservoir could force CAP to leave behind some of its 1.5 million acre-foot share of river water in the next year or two. It would likely mean some central Arizona farms would go without.

An acre-footcan supply about two to three Southwest families for a year, experts say.

Now the groundwater district is seeking 113,000 acre-feet of water over the coming century, according to a draft plan of operations that it must finalize and submit for state approval by year's end. More than half of that water will be required within the next 20 years, as tens of thousands of homes spring up on lots within the district.

One way to cover some of the need is to buy unused water from Yuma farmers, whose rights to the river are older than and legally superior to CAP's.

Yuma Mesa Irrigation and Drainage District farmers like Mark Spencer are burning lemon trees because the groundwater district paid them.

The payment of $750an acre a year for three years, with an option for a second three-year contract,is more than just some cash in hand for leaving some of their water in Lake Mead. It's also what makes it feasible to forgo some of their fruit sales while triple-digit Arizona heat takes a couple of summers to bake pests and harmful spores that ­fester in soils when ­citrus trees approach the end of their productive lives. Immediately planting another crop before nature cleans the soils could harm the new trees.

"I thought about ­(fallowing) as an opportunity to improve my citrus plantings," Spencer said.

The other option, he said, was to tear out the trees and plant hay while resting the soil for a couple of years — earning just $200 or less a year per acre.

Other farmers also are halting hay irrigation to participate in the program. To qualify for the payments, they must prove they have irrigated the land four of the last five years.

A big if

The groundwater district will study the water savings for three years, while rotating farmland in and out of the program. Then it will do another three-year cycle before deciding whether to pursue long-term leases.

"(Farmers) would not relinquish entitlement to Colorado River water," said Perri Benemelis, the groundwater district's senior water-resources analyst.

But they would agree to a negotiated price allowing water that otherwise would flow from Lake Mead to Yuma to take a detour into the CAP canal at Lake Havasu City.

The district predicts the test fallowing could save 9,000 acre-feet a year — nearly 3 billion gallons. But if leasing happens after that, the numbers could be bigger or smaller, depending on who wants to sell.

It's a big if, in some observers' minds, if for no reason other than the cost.

"I suspect a very complex and expensive arrangement would be required to entice senior users," said Tom Davis, who manages the Yuma County Water Users' ­Association. "That is not to say it would not be possible in the future under extreme circumstances."

But that's not to say, either, that he could support it. He noted that the Yuma Valley — with an economy heavily dependent on agriculture — produces most of the winter lettuce grown in the U.S., plus other winter vegetables and wheat.

"We require both food and water for life," he said.

It's also difficult to predict how costly such a project would be for consumers. Members of the groundwater district pay about $500 an acre-foot. But nobody believes that water will do anything but escalate in price as Arizona grows, and some observers believe the district will have to raise at least several hundred million dollars for purchases in the coming century. The district says rates will rise, but it hasn't said by how much.

Surrendering water to the big cities, for whatever period, is also a touchy suggestion.

"Of course there are people that don't like the idea no matter how it's done," Morgan said. He is meeting with nervous farmers from other Yuma irrigation districts to assure them fallowing affects only fields that were about to rotate.

This type of rural-urban transfer is likely to accelerate once it starts, and farmers would be wise to collaborate and plan for it, said Grady Gammage Jr., a lawyer, Arizona State University sustainability scholar and former CAP board member.

"There are going to be more arrangements of this kind reached in the future," Gammage said. "But I think there ought to be a more open dialogue about the relationship of farming and urban use in Arizona."