The Eastern Snake Plain Aquifer of southern Idaho is one of the largest underground pockets of water in the world.
It's the sole drinking water source for 300,000 people and allows this once sage brush desert to bloom with crops and cattle. But years of drought and falling flows have also turned it into a battleground. It’s a fight the whole arid West may soon face.
Guy Hand spoke to water users and others in the area and files this report.
Joe Cooper: "Right now we're right on the main gate on the Milner dam. It's kind of overcast and windy and cold up here."
It may not have sounded like an historic moment in October when watermaster Joe Cooper prepared to open an irrigation gate above this flat expanse of reclaimed Idaho desert.
Joe Cooper: "Ah, he just hit the button and the gates starting to rise."
But never in Idaho history have water users purposely let precious water pour out of a reservoir into fields that have already been harvested.
Joe Cooper: "The water's just barely starting to run out now. Can you hear it?"
The hope is that all that water—enough to flood nearly 30,000 acres a foot deep—let out over several weeks, will seep into that fallow ground and help refill the underlying aquifer.
Joe Cooper: "It's kind of an experiment. We've never done this this time of year, so…."
That's because last summer the state of Idaho threatened, for the first time ever, to shut down wells on thousands of acres of farmland — unless groundwater pumpers figured out a way to put back some of the water they'd pumped out of the aquifer.
In an 11th hour deal, groundwater pumpers arranged to buy water from other farmers, open that gate at Milner Dam, and avoid, for the moment at least, a confrontation that some say could devastate Idaho's economy.
Rocky Barker is environmental writer for the Idaho Statesman.
Rocky Barker: "This battle started when somebody developed a pump strong enough, powerful enough to suck that water out of this deep aquifer. And that happened in the 1940s. Suddenly all of this land that was out there became fair game. And there was a general belief among many water users that the aquifer was unlimited."
A half century later, the limits are showing.
Randy MacMillan: "The spring users in the Thousand Springs area are almost like canaries in the mine. We're the first ones to see the impact of mining the aquifer."
Dr. Randy MacMillan is with Clear Springs Foods, the largest producer of farm-raised rainbow trout in the world. Clear Springs depends on the water that naturally gushes out of the aquifer downstream from all those groundwater pumps. MacMillan says those pumps, combined with drought, are hurting his business.
Randy MacMillan: "In just the past five years, we've lost probably about $20 million in revenue, in gross revenue, from lack of fish production at two out of four of our farms."
Clear Springs has older water rights than the ground water pumpers. MacMillan believes Idaho law requires that senior right holders receive their legally alloted water—even if newer users have to be cut off.
Rocky Barker: "When it comes down to it, it's those farmers who believe first in time is first in right versus other farmers who believe the Idaho constitution says that doesn't mean you can shut other people off."
This is the new frontier in Western water law. Should the burdens of scarcity—in a time of global warming—be shared among all users? Or should the West stick with traditional water right law?
Idaho is the first Northwest state to face these questions—but…
Lynn Tominaga: "Idaho is no different than Oregon or Washington."
Lynn Tominaga directs the Idaho Groundwater Appropriators, the group that represents the pumpers.
Lynn Tominaga: "A prime example is the water rights issue that happen in Klamath Falls. Throughout the West there are problems with drought and we have to find better ways of managing the water so that you don't have these economic catastrophes take place because somebody happens to be a little short of water."
The whole matter is going to court. Hearings begin this week in Boise and will likely lead to the Idaho Supreme Court. Again, writer Rocky Barker:
Rocky Barker: "There are some wonderfully novel legal issues that are going to come out of this. And it will decide for us the future of this state."