As California descends ever deeper into a potentially devastating drought, with residents facing unprecedented demands to cut water use, everybody is looking for somebody else to blame. But perhaps the most high-profile scapegoat in the parched Golden State is not a somebody but a something: the highly nutritious, increasingly notorious almond.

California grows 80 per cent of the world’s almonds, but it is two other widely reported statistics that have caused controversy: cultivating a single thirsty almond takes more than a gallon of water, and almonds alone account for almost 10 per cent of California’s agricultural water consumption. Agriculture takes up 80 per cent of the state’s total human water usage, which means almonds use some 8 per cent of the precious supply: more than the entire city of Los Angeles.

As California enters its fourth year of severe drought, farmers in the Central Valley are struggling to keep their crops watered and many have opted to leave acres of the fields fallow (Getty)

Now, however, almond growers are pushing back against the negative coverage, with a PR drive to persuade consumers that the much-criticised kernel is as healthy for the environment as it is for their digestive systems. “All food requires water,” said Stacey Humble, marketing chief for the Almond Board of California (ABC). “When you read that one gallon figure without any context, it may sound like a lot. But almonds don’t use that much more water than many foods do.” California produces about half of the fruits and vegetables in the US. “To say a particular crop is to blame for the drought situation is neither fair nor useful,” said Professor Richard Howitt, an expert in agricultural economics at the University of California’s campus at Davis. “Almonds are a market crop and people like them. Nuts are high water users, but so are apricots and peaches and other fruit. To single out almonds, which are healthy, water-efficient and in demand, is misguided.”

Incredible pictures of the California drought Show all 15 1 /15 Incredible pictures of the California drought Incredible pictures of the California drought Lemoore A sign referencing the drought is posted next to a fallow field in Lemoore Incredible pictures of the California drought Fresno Dead trees stand in a field in Fresno Incredible pictures of the California drought Lemoore A dust devil kicks up dirt as it forms over an empty field in Madera Incredible pictures of the California drought Oroville Low water levels are visible at Lake Oroville near the Bidwell Bar Bridge in Oroville Incredible pictures of the California drought Raymond A fisherman sits on the banks of Hensley Lake in Raymond as California enters its fourth year of severe drought, the State's reservoirs are shrinking due to lack of Sierra snow pack and very little rain. Hensley Lake is currently at 8 percent of its 90,000 acre feet capacity Incredible pictures of the California drought Raymond Low water levels are visible at Hensley Lake in Raymond Incredible pictures of the California drought Raymond A bouy sits on what used to be the bottom of Hensley Lake in Raymond Incredible pictures of the California drought Los Padres National Forest Dead and dying trees are seen in a forest stressed by historic drought conditions in Los Padres National Forest near Frazier Park. According to an aerial survey conducted by the U.S. Forest Service in April 2015, about 12 million trees have died in California forestlands in the past year because of extreme drought Incredible pictures of the California drought Firebaugh Dry cracked earth is visible near an almond orchard in Firebaugh Incredible pictures of the California drought Los Angeles An empty water reservoir is seen in the hills above Los Angeles Incredible pictures of the California drought Rancho Santa Fe Aerial view overlooking landscaping in Rancho Santa Fe, California Getty Incredible pictures of the California drought Rancho Santa Fe Aerial view overlooking landscaping in Rancho Santa Fe, California Getty Incredible pictures of the California drought San Diego Aerial view overlooking landscaping in San Diego, California Incredible pictures of the California drought San Diego Aerial view overlooking landscaping in San Diego, California Getty Incredible pictures of the California drought San Diego Aerial view overlooking landscaping in San Diego, California Getty

America’s almond consumption has more than tripled over the past decade. Though strictly a seed, not a nut, the almond recently surpassed the peanut as the most popular snack in the genre. It is thought to be effective in combating obesity, diabetes and arthritis, and recent research has suggested it can also reduce the spread of cancers and lower the risk of Alzheimer’s. It is little wonder, then, that the shelves of health food shops across California and beyond heave not only with packets of almonds, but with jars of almond butter and cartons of almond milk. Almond growers and their allies note that the kernel’s hull is also put to use as feed for dairy cattle, which means almonds help to make not only almond milk, but also good old-fashioned cow’s milk.

More than two-thirds of California’s almond crop is exported, much of it to China, which some critics argue constitutes an export of valuable water. Yet a report by the ABC claims California earned $11bn (£7.2bn) from its almonds last year, accounting for 15 per cent of the state’s total agricultural value, and making its 10 per cent water share seem like a bargain.

For farmers, those margins are too big to resist, even during a drought. Many fields that once grew cotton or vegetables are now filled with nuts. Between July 2013 and July 2014 the state’s growers bought more than eight million young almond trees – although many of those would have been ordered from nurseries before the scale of the dry spell became clear. Almond orchards now cover close to a million acres of California.

Earlier this month, with the drought entering its fourth year, Governor Jerry Brown unveiled an action plan that for the first time in the state’s history includes mandatory cuts of 25 per cent in urban water usage. Some complained that the cuts did not extend to the agricultural sector, although farmers pointed out that they were already suffering.

For the second year in a row, farms have been allocated a 0 per cent share of the water from the irrigation canals of the federally controlled Central Valley Project, which carries rainfall and melt water from the wetter regions of northern California to the state’s agricultural heartland. As a result, at least half a million acres of farmland lay fallow in 2014. While some producers uprooted almond trees, most chose to do without other, less profitable crops.

That is another source of controversy: unlike vegetables, almond trees must be watered year round. Without access to federally allocated water from the irrigation canals, many farmers now source their supply from wells. Excessive groundwater use, says Prof Howitt, is the most pressing water problem faced by the state. Underground aquifers that collected over centuries are being quickly depleted, in some areas causing the very earth to sink by several feet. Late last year Mr Brown at last signed legislation to manage and regulate groundwater use.

Almonds are undoubtedly a thirsty crop, but growers point out that they are far more efficient than beef or dairy. Recent figures compiled by the Los Angeles Times suggest that it takes more than 100 gallons of water to produce an ounce of beef, compared with less than 50 for an ounce of almonds. Advances in irrigation technology, the ABC says, have lowered the amount of water needed to produce almonds by a third.

Some say the wrong product has been demonised, and that opprobrium ought instead to be heaped on alfalfa hay, a low value crop sold as feed to dairies overseas, which takes up even more of the state’s agricultural water supply than do almonds: a whopping 15 per cent in recent years.