Doing the right thing in the environs of the University of California, Davis – one of the foremost agricultural institutions in the US – means driving a carbon efficient car. And having a lawn that’s burned dry.

California’s worst drought on record is forcing people to cut back radically on water use – and that means letting lawns die, and cars get dusty. There was considerable rainfall last month, but it was not nearly enough to replenish the badly-depleted water resources.

Higher than average temperatures – particularly during the winter months – have combined with a lack of rainfall to produce severe drought conditions across much of the state.

Water restrictions have been brought in following the imposition of a drought emergency in January last year.

Dreaming of a wet winter

“If we don’t have rain in significant amounts by early March, we’ll be in dire straits”, says Professor Daniel Sumner, director of the Agricultural Issues Center at Davis. “Historically, California’s water has been stored in the snow pack in the mountains, but warmer winter temperatures have meant the pack has been melting.”

“The agricultural sector has made considerable advances in limiting water use, and new, more drought resistant, crops and plant varieties have been introduced, but aquifers have been pumped and they are not being replenished.

“In the past, massive projects were undertaken to distribute water round the state, but now there’s not the money available to do any more big-time plumbing work. Also, the regulations on diverting water for agriculture use are very tight – rivers can’t be pumped if it means endangering fish stocks or other wildlife.”

Whether or not climate change is causing the drought is a matter of considerable debate. A recent report sponsored by the US government’s National Oceanic and Atmospheric Administration (NOAA) says natural oceanic and atmospheric patterns are the primary drivers behind the drought.

A high pressure ridge that has hovered over the Pacific off California’s coast for the past three years has resulted in higher temperatures and little rainfall falling across the state, the report says.

However, a separate report by climate scientists at Stanford University says the existence of the high pressure ridge, which is preventing rains falling over California, is made much more likely by ever greater accumulations of climate-changing greenhouse gas emissions in the atmosphere.

It’s not just the groundwater that’s depleted

Whatever the cause of the drought, the lack of rain is doing considerable environmental and economic damage. The Public Policy Institute of California, a not-for-profit thinktank, estimates that $2.2 billion in agricultural revenues and more than 17,000 jobs have been lost as a result of the drought.

Thousands of acres of woodland have been lost due to wildfires, while fisheries experts are concerned that severely depleted streams and rivers could lead to the disappearance of fish species in the area, such as coho salmon and steelhead trout.

The drought is not limited to California. Adjacent states are also affected, and over the US border to the south, in Mexico’s Chihuahua state, crops have been devastated and 400,000 cattle have died.

Frank Green, a vineyard owner in the hills of Mendocino County, northern California, says: “The vines are pretty robust and, despite the drought, our wines have been some of the best ever over the past two years.

“But there’s no doubt we need a lot more rain, and plenty more could be done on saving and harvesting water. Farmers have cut back on growing water-hungry crops like cotton, but California is still growing – and exporting – rice, which is a real water drinker. How crazy is that?”

Kieran Cooke writes for Climate News Network.

Also on The Ecologist:

• ‘Fish before agribusiness! California river tribes demand water‘ by Oliver Tickell;
• ‘Climate change and the downfall of California’s big agriculture‘ by Joshua Frank.