The wet season arrived early this year for much of California, even as Lake Mead has dropped to record low levels. And that raises big questions for some Californians, especially farmers in the Imperial Valley who use the lion's share of water from the Colorado River.  After an unrelenting 11 years of drought on the river, many in that naturally arid corner of the state are forced to confront their future.

As the unofficial ambassador for Imperial Valley farmers, Vince Brooke tours visitors around for the local irrigation district.   Mostly, that’s busloads of water wonks from various Western cities.  And as they bounce along the bumpy roads, their comments can be less than diplomatic. 

"We're water wasters, we're water hogs, the ag sponge," Brooke says, quoting some of the things he’s overheard. "They think, 'this is kind of a waste of time, and a waste of water.'" 

The water they're talking about is the Colorado River, the lifeblood of a billion dollar agricultural industry in the Imperial Valley.  

"This is the only source of water for the imperial valley. All the drinking water, all the agricultural water, this is it," says Doug Cox, who manages Imperial Dam.  It shunts Colorado River water into the All-American canal, which crosses 82 miles of desert just north of the Mexican border to reach Imperial Valley farms.   When the dam and canal system were completed in the 1930s, they were considered one of the wonders of the world.  

As one educational film from the era trumpeted, "The imperial valley, once dry and barren, with the help of water from the Colorado yields rich crops when irrigated!" 

Now, around 90% of the vegetables that Americans eat in the winter are grown around here.  Lettuce, potatoes, sweet corn, carrots, broccoli, cauliflower, as well as alfalfa and other forage crops. 

Ralph Strahm's family has been farming here since right after World War I, around the time Western states divied up water from the Colorado River.  The strategy was pretty much "first come, first served," and Imperial Valley farmers got served a torrent.  Priority rights to almost three quarters of California's allotment.  More water than what Arizona and Nevada got combined.   

That was almost a century ago, but Strahm says there's still good reason so much water should go to farms like his.

"The rest of the nation is becoming a service economy, and the Imperial Valley is producing something.  So many of our jobs in the manufacturing industries have ben exported away from the United States.  We're keeping those jobs here."

But they're not keeping all the water here, anymore.   Under pressure from federal officials, farmers have reluctantly given up some of it, to the more populous and powerful cities, of Los Angeles and San Diego.  Strahm shows me a controversial result of that transfer as we walk along an irrigation channel.  He points to a big padlock securing a gate across the channel's mouth. 

"That lock is to prevent water from being put on this field for the term of a fallowing contract," he explains. Growers fallowed about two percent of the valley’s farmland this year.   Cities pay thousands of dollars for each unfarmed acre.  It can actually be cost effective for farmers right now, while crop prices are so low.   But Strahm says it hurts the valley as a whole.

"The tractor salesman is hurt. People that sell fertilzer and provide other services to farmers. They’re impacted," Strahm says.

Compensation, for now, is going to those who've been hurt. And the fallowing program's only supposed to last a few years, while farmers make their irrigation systems more efficient. 

But after eleven years of drought in the Colorado River Basin, Lake Mead, which supplies water to Imperial farmers and much of the Southwest, is at its lowest level ever.  Add the expected effects of climate change, and models show a 50% chance it could dry up by 2057, unless current water use in the region changes drastically.  

One obvious target for that change is agriculture in the Imperial Valley.   

"We don't need our agriculture in the western U.S. to feed the population," says Doug Kenney, head of the Western Water Policy Program at the University of Colorado.  "It's an important part of the economy, but if agriculture were to go away, life would go on  in the western U.S.  I imagine what will happen is money will flow from cities to farmers, and water will flow from farms to cites," he says. 

But he says both sides should be bracing for a bumpy and less than diplomatic ride.