The sinuous Gila River arises from springs and caves in the Black Range Mountains just west of the Continental Divide in New Mexico’s Gila Wilderness. From there, it tumbles down box canyons before twisting through the ranches and farms of southwest New Mexico’s Cliff-Gila Valley and onto the cactus dotted plains near Silver City. Once, the Gila flowed 650 miles all the way to the Colorado River on the California-Arizona border, but today, the waters disappear in the desert outside Phoenix.
As New Mexico’s last major dam-free river, the Gila is an anomaly in an arid region where states fight to control every last bit of water. But a decision is near that could alter the river’s flow forever. New Mexico’s nine-member Interstate Stream Commission is considering three proposals to divert up to 14,000 acre-feet of water from the Gila —about 4.5 billion gallons — for cities, farms, and people in the four counties of southwestern New Mexico. The commission announced on Tuesday that it’s postponing its final vote until later this fall.
The diversion proposals are among 15 — including municipal water conservation and irrigation ditch improvements — that the commission is weighing before a December 31 deadline, when it must choose whether or not to take advantage of water it’s entitled to under the 2004 Arizona Water Settlements Act. The law reserves $90 million in federal funds to help improve the water supply in the southwestern part of the state, either through conservation programs, or through building a diversion. But the latter comes with an additional $46 million subsidy.
The commission has spent millions analyzing the technical feasibility, economic costs, and environmental impacts of the various proposals as well as on studies of the Gila itself — from its hydrology and riparian ecosystems, to how climate change will impact future flows. But with many inquiries still in progress, key details surrounding the diversion proposals remain murky.
The basic idea, however, is that they would draw water only during major flood events like those that accompany the late summer monsoons — when the river flows at 30,000 cubic feet per second, unleashing a half-mile wide torrent filled with trees and boulders.
Because of the volume, the commission maintains that the diversions would have a minimal impact on the Gila. According to commission Deputy Director Craig Roepke, doing this could actually help the Gila, stressed from years of intensive agriculture. Though it has no large, channel-blocking dams, such as those spanning the Colorado and the Rio Grande, the Gila does have seven major irrigation diversions. In many years, farmers draw so much water that parts of the river run dry, wreaking havoc for farmers and fish alike. If monsoon floods could be stored, Roepke says some of that water could be strategically released to ease dry times.
But Mike Fugagli, an ornithologist who lives in the Cliff- Gila Valley, insists there’s “no way” the state can get 14,000 acre feet per year just by taking water from those big flood events, which are relatively rare. He argues that they’d have to draw significantly from medium-sized floods too — those in the 400-4,000 cubic feet per second range, which are critically important for maintaining vigorous growth in the Gila’s riparian ecosystems.
From the window of his house, Fugagli looks out onto the Gila’s broad flood plain, home to diverse wetlands that, he says, are “almost like magic,” packed as they are with life in an otherwise arid-looking landscape. He worries that altering the magnitude and frequency of those medium floods will have a devastating impact on the rich riparian forests that sustain numerous endangered species like the southern willow flycatcher.
Still Roepke, an avid boater, says he sympathizes with opponents. He’s taken his 14-foot raft down the Grand Canyon; the first vacation he took in over a decade that didn’t involve whitewater was his honeymoon to Italy last year. From a recreational viewpoint, he’d rather leave the river the way it is too, he says, but “the whole thing is a lot more complicated (than that). We can’t take (the diversions) off the table right now.”
The environmental impact isn’t the only aspect of the diversion proposals that’s ambiguous. Critics also charge that its unclear where most of the money will come from and to whom the water will actually go.
The commission argues that wells drawing water from the Mimbres Basin aquifer, upon which much of southwestern New Mexico relies, are dropping by 0.3 feet per year — the brunt of which will fall on farmers.
But with costs for a diversion running from $400-500 million, federal money would only cover a small fraction of the anticipated expense. Roepke admits the commission has not yet figured out where the balance will come from.
A recent report by the Boulder-based environmental group, Western Resource Advocates, found that southwest New Mexico could more than make up the projected 35 acre-foot gap in domestic and municipal water supply through conservation methods alone, like those already taking effect in Deming and Silver City — a much more affordable option, says Stacy Tellinghuisen, who co-authored the report. The report did not factor in agricultural use because, she says, farmers would not be able to pay for the additional water — no matter how much they say they need it.
Choosing the diversion route, however, could raise average annual water bills at the homes it serves from $200 a year to over $630. Since tripling the water bill is politically and socially infeasible, the report found, the cost would likely fall to state taxpayers.
“We should really take a look at this as a turning point for New Mexico,” says Adrian Oglesby, director of the University of New Mexico’s Utton Transboundary Resource Center and the commission’s former Gila water attorney. “We’re in a state of ambiguity right now... Which path are we going to go down?”
Oglesby sees the fight over the Gila as a window into the evolution of Western water management — from building big dams and engineering projects to smaller local projects focused on making better use of the water available.
“There are folks saying you have to grab this water because if you don’t grab it now you’re never going to get it,” he says. “No matter the cost and even if we don’t know what we’re building yet.”
Sarah Tory is an editorial intern at High Country News. Follow @tory_sarah