All the leaves are brown
Farmers have been raiding groundwater to survive a four-year drought. Better solutions are needed
PARCHED fields, shallow lakes and wilting trees testify to California’s four years of drought. From Palm Springs to Palo Alto, lawns of luscious green are now an ugly brown. Scrubby grassland grows in once-fertile fields. The Golden State is short of more than 1.6m acre-feet (2 billion cubic metres) of water even before summer’s start. But at the Sacramento County Fair last week, children encased in inflatable spheres bobbed across giant paddling pools and pampered pigs were sprayed from mist bottles. “It’s not so bad this drought, we’ll get through it,” said one young goat-keeper.
Together with the San Francisco Bay, river systems and engineered channels near Sacramento (known as the Sacramento-San Joaquin Delta) form the largest estuary on America’s Pacific coast. It is the hub of California’s water supplies. Rights to its waters were snatched up in the wake of the gold rush and, even in a particularly savage drought (see chart), it is hard for the state to curtail water use by those who have held them for more than a century. Some lucky farmers have therefore quenched thirsty crops as their rights permit; many of those farther south have seen their lands scorch instead.
So the offer on May 22nd by Delta farmers to reduce their water use by a quarter came as a pleasant surprise. At the beginning of April California’s governor, Jerry Brown, had ordered city-dwellers to cut water consumption by a quarter. The farmers’ offer seemed a step towards fairness.
It came with a catch, of course. In return, the state must guarantee it will not restrict use of the farmers’ remaining supplies in the future. But the concession is welcome anyway: not counting what is set aside for the environment, 80% of water used by Californians is for agriculture.
Felicia Marcus, who chairs the State Water Resources Control Board, calls the deal “pragmatic”. She says farmers would rather cut back now than risk reductions later. But it will not be easy to check up on their efforts. Meters are not in general use and some rights-holders need report what they do with water only every three years. Shawn Coburn, who grows tomatoes, grapes and almonds in Firebaugh, doubts the intentions behind the offer: “Those guys are blowing so much smoke up people’s asses it’s not even funny,” he says.
Roughly two-thirds of California’s rain falls in its northern regions, but two-thirds of water use by its 39m residents is in its central and southern areas. Since there has been little precipitation for four years the state’s 1,400 reservoirs have just a year’s supply left. New Melones Lake, the state’s fourth-largest reservoir, is less than a fifth full. Ruddy rings below the tree line of its steep sides show how far it has fallen.
Locals are not too worried. Vicki McFall, who owns a still-thriving flower shop in nearby Angels Camp, says the lake was much lower during the six-year drought that ended in 1992. “We’re all more conscious about water now, though,” she admits, “I only give my nursery plants water I’ve already used for stems and bouquets.” Ellen Hanak, from the Public Policy Institute of California, remains calm too: “The end is not nigh. We are used to having a highly variable climate and our economy can deal with that.”
California has survived dry spells throughout its history. But the length and severity of the current drought may be a result of modern environmental factors. Recent studies agree that a region of high atmospheric pressure, known as a blocking ridge, has been disrupting wind patterns off California’s coast for the past three winters, diverting seasonal storms northwards. Scientists from Stanford University believe greenhouse gases have made the formation of such a blocking ridge more likely. Using computer simulations and statistical models, they found the chances of the ridge forming were three times higher in the presence of modern greenhouse-gas concentrations than those found just before the industrial revolution.
Barton Thompson of the Stanford Woods Institute for the Environment says he worries more about California warming. Since the 1980s average temperatures in the state have been higher than they were in the 50 years before; 2014 was the hottest year on record. A changing climate sees warm and dry periods more often occur together in California, according to another Stanford study. This makes the severity of droughts worse. Extra heat means that moisture evaporates from the soil faster, so plants need more watering. And less snow falls: the water content of the Sierra Nevada mountains’ snowpack, which acts as a natural water-storage system until the spring thaw, was just 5% of its April 1st average last month. “Droughts will be more frequent in years to come and they will be worse,” reckons Mr Thompson.
As surface sources of water have dried up, farmers and others have turned to groundwater to replace their missing supplies. As much as 65% of the water used in the state last year may have been pumped to the surface—up from 40% during average years—according to the California Water Foundation, an environmental group. It replaced about three-quarters of lost surface sources. “The pumping cannot go on as it has for the past four years,” believes Ryan Jacobsen, a farmer in Fresno who also runs his county’s Farm Bureau.
Well-raiding has led to subsidence and damage to underground layers of sand and clay that might otherwise have held more water in the future. It also means salt water can enter aquifers on the coast. Yet California was the last Western state in America to embrace laws for managing groundwater use: legislation was passed in September 2014. And its effects will not come quickly. New management plans for underground sources have until 2040 to become environmentally sustainable.
Meanwhile, guzzling groundwater makes good business sense for many farmers. California is the nation’s largest farm state, with sales of farm products worth $48 billion in 2012. It grows more than a third of America’s vegetables and two-thirds of its fruit and nuts. Health fads for protein-rich diets, perhaps inspired by those of the state’s own film stars, make its farmers “a tonne of money,” according to Mr Coburn. Irrigating orchards of thirsty almonds and pistachios used 3.8m acre-feet of water in 2010, 54% more than a decade earlier. But the value of the nuts was $4.4 billion that year, meaning farmers turned over $1,200 for every acre-foot of water they sprinkled. Alfalfa, a crop that slurped up 5.2m acre-feet of water—more than any other—feeds cows, not celebrities.
Abandoning thirsty crops could solve many of California’s water woes. Agriculture contributes just 2% of the state’s economic output and employs 3% of its workers. Nevertheless, Mr Jacobsen asks where Americans would get their fruit and vegetables without the bounty of the Central Valley. “Farmers are just borrowers of water. The consumers of their products are the ultimate beneficiaries,” he says, “and the scale on which we do things here means that middle-class people can afford to buy them.” It is precisely the area’s desert-like natural conditions that boost yields thanks to the long, dry growing season. Few consumers think about how much water has been used to grow the food they buy.
What else can be done? California’s cities provide some lessons. The amount of water used by residents of Los Angeles and San Francisco is lower than it was in 1980—despite surging populations. But cities can have their fruit and eat it too. Rich urban areas can afford to buy extra water when needed. They can also pay for costly desalination plants (as Santa Barbara has done). Tiered pricing, under which consumers pay more above certain usage levels, can discourage water waste too—but their legality was successfully challenged in a state appeals court in April.
Some urge setting up more water-trading markets, to help the flexibility of supplies. Others want to turn Central Valley lands into a solar-energy hub. Ms Hanak sees better data as a priority. “For the centre of the world’s technology economy,” she says, “we have a pitiful information system at the state level about water.”