The lush front lawns of Los Angeles are in the full bloom of spring, and it’s difficult to believe the Golden State is about to turn brown. But that is the inevitable implication of the drought, and of new rules which call for a 25 per cent cut in urban water use.

The mandatory restrictions are the first in the state’s history, but they look set to deepen long-standing divisions between the wealthy and the less well-off, and between California’s packed cities and its vast, sparsely populated agricultural areas. “It’s a different world,” Governor Jerry Brown said as he unveiled the plan. “We have to act differently.” What he did not say, however, was that some will have to act more differently than others.

In Los Angeles, whose residents use an average of 265 litres per day, an academic study found that the most affluent neighbourhoods used up to three times more water than others. In wealthy southern cities such as Malibu and Newport Beach, where people have large front lawns, consumption was more than 560 litres per capita in January.

Stephanie Pincetl, director of the California Centre for Sustainable Communities, told The Los Angeles Times: “The problem lies, in part, in the social isolation of the rich, the moral isolation of the rich.” The rich, she said, were “lacking a sense that we are all in this together”.

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

Last year was the warmest on record in California, which is in the middle of its driest spell for centuries. Scientists warn that the region may be entering a “mega-drought” lasting decades or more.

Until now, most California cities have chosen not to punish people for excessive water use, but simply to raise awareness. Beverly Hills, for example, sought to reduce consumption by 10 per cent by encouraging residents to curb their watering and use recycled water in their decorative fountains. In Santa Cruz, by contrast, heavy water users can be fined hundreds of dollars and sent to “water school” to change their habits. The city reduced its water use by 25 per cent last year.

Mr Brown’s 31-point plan calls for golf courses and other landscaped areas to cut water use, and bans watering of roadside verges. It includes schemes and incentives to replace 50 million square feet of lawn with drought-tolerant landscaping.

“The great myth of California water is that someone else is always responsible,” said Jon Christensen, of the University of California’s Institute of the Environment and Sustainability. “There are longstanding divisions between rural agriculture and urban areas, between northern and southern California.

“What I haven’t seen before is this sharp focus on the wealthy, but it still fits the overall pattern: the first thing Californians do in a drought is find somebody else to blame. But we’re all in this together, and focusing on one type of water user is not going to solve the problem.”

While battle lines are being drawn between rich and poor, a bigger conflict is brewing between town and country. As many as 95 per cent of Californians live in urban areas, and yet they use just 20 per cent of the state’s water. The governor’s mandatory restrictions do not apply to agriculture, which accounts for the remaining 80 per cent.

Farmers say they already face dramatic cutbacks because of the drought. California’s agricultural industry, which produces almost half of the fruits, vegetables and nuts grown in the US, left 500,000 acres fallow last year, losing an estimated $1.5bn.