By DAN CHARLES
The next time you pick up some California-grown carrots or melons in the grocery store, consider the curious, contested odyssey of the water that fed them. Chances are, farmers pumped that water from underground aquifers on a scale that's become unsustainable, especially as the planet heats up.
Facing an ongoing drought that is squeezing surface water supplies, farmers are extracting groundwater at higher rates to continue growing food as usual.
California's farmers probably will pump an additional six to seven million acre-feet of water from their wells this year, above what they normally use, according to Josue Medellin-Azuara, a water expert at the University of California, Merced. That quantity would cover 10,000 square miles with a foot of water, and far exceeds the amount that naturally replenishes the aquifer, even during a year with normal rainfall.
"It's a huge amount,"says Steve Jackson, a farmer in Visalia who helps to manage 40,000 acres of almonds and other crops. "I'd say 90 to 95 percent of our crop demands this year are going to be met by groundwater."
This year, however, may mark the beginning of the end of California's great groundwater grab. The state is preparing to phase in new limits on groundwater pumping that will force painful adjustments on the state's farmers.
California is a powerhouse of food production, growing some 40 percent of the country's fruit, vegetables, and nuts. Yet the production depends on a supply of water that's increasingly fragile and unreliable as the climate warms.
"Drought reveals the lie of a place," says Mark Arax, the Fresno-based author of The Dreamt Land, a history of California's water conflicts. "The lie is our ambition. We've taken on too much."
In good years, an intricate system of dams, aqueducts, and irrigation canals captures water from rivers and melting snow, much of it in the northern part of the state, and moves that water to fields in the wide Central Valley where most crops are grown. The system also supplies coastal cities, but agriculture remains the largest consumer of water.
This year, rivers are running low. The state's biggest reservoirs contain less than half the average amount of water, and farmers have been forced to rely on their wells. "This year, there is no allotment, because there is no water," says Kathy Briano, referring to the amount of water that farmers are assigned for irrigation use. Briano grows almonds near the town of Porterville, and she's relying on her wells instead.
Until now, groundwater use in California has been unrestricted. Farmers and cities could pump as much as they wished. And there was a time when that water source seemed inexhaustible.
The Central Valley aquifer is like a giant, multi-layered lake beneath the ground. "A hundred years ago, when you tapped a foot into the earth, in certain parts of the valley, the water would gush out," Arax says. At that time, wells typically only needed to be 50 or 80 feet deep.
But year after year, towns and farmers --- but mostly farmers --- pumped more water out of the aquifer than nature put back in, and the water table fell. Today, farmers and towns are drilling wells over a thousand feet deep. Extracting so much water even changed the region's geology."As you draw the water up and out of the earth, the earth itself then collapses and sinks," Arax says. "We're not sinking by inches. We're sinking by feet."
Briano says the problems first became obvious during the drought of 2014-2015. "Everybody was pumping," she says. "You had to pump all that you needed, and you just brought that groundwater down to nothing."
On her ranch, the water table dropped by 60 feet. The well that supplied water to her house went dry. The same thing happened to hundreds of people who relied on shallow wells in the nearby town of East Porterville. "People were without water, and they had to bring water tanks in. They had no water at all!" she says.
During that drought, there was growing pressure to enact limits on groundwater use. Susana De Anda, executive director of the Community Water Center, in the town of Visalia, was among those pushing for change. "When 90 percent of our valley residents rely on groundwater, we have to be sure that we're sharing that for all beneficial uses," she says. "That means that we should not over-pump."
In 2014, California passed the Sustainable Groundwater Management Act (SGMA). It requires big changes, but they will be enforced only gradually, over the next two decades.
Under this law, overuse of the aquifer must end by 2040. By that date, use and replenishment of the state's groundwater must be in balance.
State and local officials now are coming up with limits on groundwater use to achieve this. In practice, it could mean that farmers in the San Joaquin Valley, which occupies a large area of the Central Valley between Sacramento and Bakersfield, will have to cut their groundwater pumping by 70 or 80 percent by 2040, compared to what they're using this year.
In order to enforce these limits, some authorities are requiring meters on wells. Others are monitoring water use through satellites that can detect which crops are being grown.
The reaction among farmers has been mixed. Some, like Steve Jackson, agree that limits are necessary, even though groundwater has kept his farm alive in drought years. "It is a lifeline, but I think that it's a lifeline that we've all taken for granted, and it's not infinite,"he says. "I think that's what's coming home to all of us."
The limits probably will mean that some land will no longer grow crops, although there's dispute about how much. One study, backed by the agricultural industry, predicts that a million acres, or 20 percent of the fields in the San Joaquin Valley, will be taken out of production. Other researchers think it will be half that much. Farmers are likely to adapt by shifting their limited water supplies to their most valuable crops. They also will be able, for the first time, to buy and sell groundwater allotments, shifting the water to the places where it's worth the most.
Other farmers, like Kathy Briano, reject the prospect of idling fertile Central Valley land. Briano agrees that it makes sense to protect the aquifer. But to make up for it, she wants the state to deliver more water from dams and reservoirs, to which she says the farms are entitled. "My solution is, you need to bring us more water," she says. "We can't keep taking from the valley, because we're taking away [food] production, and where can we grow everything? Right here!"
Mark Arax, the writer, says the changing climate is likely to breed more conflicts like this, also in other parts of the country. "How we deal with this becomes an example for the rest of America, when it comes to their doorstep," he says.
The California dream was born in the Gold Rush, claiming nature and re-shaping the land. Now, Arax says, it's time to re-invent that dream.
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