As the United States’ top farming state, California has  —  or had  —  a $35 billion farm industry. Besides being the country’s fourth-largest beef producer, the state grows about half of our fruits, vegetables and nuts. Much of it grows in the San Joaquin Valley, which has been called the world’s most productive agricultural region, thanks to an irrigation system that relies mostly on snow melting hundreds of miles away, collected and transported through a system of dams and canals.

This year, as the state endures its third year of uninterrupted drought, all of that is in jeopardy.

Droughts came and went in the 1970s and the 1990s, but expectations are that this one will be worse than those. For one thing, about 10 million moved in to the state since the last drought, bringing with them their demands for showers, toilets and sprinkler systems; for another, the rules governing how much water is available for agriculture are not the same. There are restrictions on the amount of water farmers can pump, imposed to protect some fish species  —  including the delta smelt  —  which exacerbate the scarcity and create what some call a “man-made drought” on top of the natural one.

California farms may take as much as 80 percent of the state’s water usage (according to the Pacific Institute) or as little as 40 to 60 percent (according to the farm industry and the government). Whichever figure is more accurate, what’s certain is that farmers have learned that federal water deliveries will be nonexistent this year, and state water allocations could be just 15 percent of the amount requested, although even that level is in doubt. Predictions are of economic losses up to $3 billion and 95,000 agricultural jobs.

Not surprisingly, in response, many farmers are planting far less or not planting at all; some will try to use more expensive well water to irrigate what they can. This will all be felt in the grocery store shortly. In Fresno County, for example, farmers plan to grow about half the lettuce they grew last year; that shortage is likely to raise consumer prices. The California Farm Bureau predicts that the sizable reduction in California farm output will lead to more imports  —  an effect that could also lead to a price increase. (Overall, food prices rose 5.5 percent last year, while consumer food spending fell a record 2.4 percent. Some experts had predicted moderating food prices this year, but California’s situation could render those predictions meaningless.)

With water scarcity becoming such a major, hot-button issue (not just in California, but all over the globe), you might be seeing more reports like the one called “Saving Water: from Field to Fork,” which was presented to the United Nations in May 2008; it concluded that vegetarian diets are the most efficient in terms of water usage. Another paper, this one from a researcher at University of California, Davis, stated that eating an entirely vegan meal requires less water than is needed to grow one serving of chicken and one-tenth the water needed for one serving of beef.

Such findings are likely to get the attention of the media and consumers as California agriculture struggles, and we all pay the price.