San Joaquin Valley farms are laying off workers and letting fields lie fallow as their water ration falls.

A former farm is graded and put up for sale for commercial development near Bakersfield. Urgent calls for Californians to conserve water have grown after the final Sierra Nevada snow survey of the season indicated a snow depth and water content at only 67% of normal levels. David McNew / Getty By Alana Semuels Reporting from Mendota, Calif. — Water built the semi-arid San Joaquin Valley into an agricultural powerhouse. Drought and irrigation battles now threaten to turn huge swaths of it into a dust bowl. Farmers have idled half a million acres of once-productive ground and are laying off legions of farmhands. That’s sending joblessness soaring in a region already plagued by chronic poverty. Water scarcity looms as a major challenge to California’s $37-billion agricultural industry, which has long relied on imported water to bloom. The consequences of closing the spigot are already evident here in rural Fresno County, about 230 miles north of Los Angeles. Lost farm revenue will top $900 million in the San Joaquin Valley this year, said UC Davis economist Richard Howitt, who estimates that water woes will cost the recession-battered region an additional 30,000 jobs in 2009. Standing in a parched field in 104-degree heat, valley farmer Joe Del Bosque pointed to cracked earth where tomatoes should be growing. He didn’t bother this year because he can’t get enough water to irrigate them. He’s cultivating only about half of the cantaloupe and asparagus that he did in 2007. He has slashed his workforce, and his bills are mounting. “We can’t survive at 10% of our water,” said Del Bosque, 60, a white cowboy hat, long sleeves and jeans protecting him from the blistering sun. Desperation is rippling through agricultural communities such as Mendota, 35 miles west of Fresno, where an estimated 39% of the labor force is jobless. It’s a stunning figure even for this battered community of about 10,000 people, which has long been accustomed to double-digit unemployment rates. … But climate change is intensifying competition for this resource and may well force changes in the way the valley has been farmed for decades. …

Despair flows as fields go dry and unemployment rises