The California Drought: Everybody’s Business

Agricultural Disaster Preparedness and Recovery December 16, 2015 Print Friendly and PDF

Drought soil



If you ate your five servings (or more) of vegetables or snacked on a handful of walnuts or grapes today, chances are they all grew somewhere in California.


California’s temperate four-season climate, diverse geography, and expansive acreage of deep, fertile soils support a $44 billion agricultural economy comprised of 81,500 farms producing 400 crops, some of which grow nowhere else in the U.S.


The Golden State produces almost all the tree nuts consumed in the U.S., 95 percent of the  broccoli, 99 percent of the walnuts, and 90 percent of the tomatoes. All told, California growers provide more than half the nation’s fruits and vegetables and almost all the tree nuts.


Severe long-term drought


However, the state from which we all eat is in the midst of a severe three-year drought—the longest in 500 years—with no real relief in sight. Last year was the the driest in the state’s recorded history.


In February, California governor Jerry Brown declared a state of drought emergency, prompting both state and federal governments to approve financial aid packages to help water-strapped farms and communities.


Both federal and state officials have also told farmers that, barring a very wet spring, they won’t release any water for agriculture this year from California’s two massive water projects: the Central Valley Project and the State Water Project, which convey water from dammed rivers in the state’s relatively wet north to the urban and agricultural areas of the more-arid south.


Although irrigated agriculture makes up only three to five percent of the state’s diversified economy, it represents 80 percent of the human uses of California’s water. To help understand why, consider this: It takes more than five gallons of water to produce one head of broccoli, almost five gallons to make a single walnut, and more than three gallons to produce a tomato.


Since most Americans eat from California farms, that makes the state’s historic drought everyone’s concern.

A complex water system

“Not only do we have this mismatch of water in space, but we also have it in time,” says Jay Lund, professor of environmental engineering at the University of California in Davis (UC Davis) and director for the Center for Watershed Sciences.


“Where are all the people and all the agriculture? They’re largely [in the southern half of the state] where the water ain’t.” Lund says. He adds, “Summer is the main growing season, when we also like to have our lawns green, and when the water is definitely not falling out of the sky.”


Lund describes California’s water system as “one big hydrologic cycle, tightly managed, [with oversight by] 2000-3000 government agencies, most of them local.” These agencies collectively oversee a massive plumbing enterprise that makes California’s Central Valley the largest complex of dams, reservoirs, pumps and aqueducts in the world.


Linked to the huge water system and defying any sort of brief description is California’s complex system of water rights, its epic past and ongoing water conflicts, and the operations of the market for water itself.


“Somehow,” Lund concludes, “It actually works pretty well. All this complexity gives us a lot of resilience.”


Growing resilience


California growers have already shown resilience, according to University of California Cooperative Extension specialists and crop advisers.


Dr. Sam Sandoval-Solis, a UC Davis statewide extension water specialist, says: “Since the mid 1990s, orchards and vineyards in particular, along with increasing numbers of vegetable farms, have adopted microdrip irrigation systems and management systems that distribute water to plants with as much as 83 percent efficiency; in vineyards, it’s as high as 95 percent.”


But Sandoval-Solis worries about the significant conversion over the past decade from row crops to nuts and other tree crops. “Production is always driven by the market,” he says. “Tree crops require more water, but in good years can yield higher profits than annual crops.


“But in times of extreme drought, perennial tree crops offer much less flexibility to farmers. They have to keep irrigating their orchards to protect the value of their capital investments. They don’t have the flexibility to leave that land unplanted.”


Experts quoted in many press accounts estimate that drought will force more than a half-million irrigated acres out of production this year--mostly on land that would otherwise be planted to row crops--and that many orchards won’t get enough water to sustain good yields. The result: as much as $5 billion in losses to California’s farm economy.


To help Californians cope with the drought emergency, Sandoval-Solis notes that Cooperative Extension in California is working on three levels: “First, at the farm level to help farmers mitigate drought and make better use of the water resources they have now; second, by organizing the expertise of 20 to 25 extension water management and crop advisers to produce 16 to 20 drought educational modules to post online; and finally, partnering with the Department of Water Resources to roll out a public symposium in Sacramento at the end of April.

Is it climate change?

Mike Crimmins, a University of Arizona extension climatologist and an investigator with the Climate Assessment for the Southwest program, warns against making generalized statements or predictions about the California climate, its water resources, or its agriculture.


“When experts deliver what appear to be wildly conflicting forecasts or points of view on the situation, they’re probably all right from some perspective,” he says with a chuckle. “You have to get into the nuance in every conversation about California water.


“When you look into the deep climate record, the West has been prone to both extended wet periods and decades-long droughts. This drought is defying the forecast models, but in the Paleo context, it’s not entirely unprecedented.

“The flip side of all the technological advances that have made California so agriculturally productive and such an attractive place to live is stress on the resource. All human change stresses the water resource.”

“Is climate change part of this drought? Yes,” Crimmins says. “There’s overwhelming evidence for global climate warming, which makes climate change part of everything right now. But it’s difficult to determine in real time what part of it is due to natural variability and what’s due to climate change. It’s a subtle background.”

Crimmins continues: ”For years, growth and change in the region have largely ignored climate matters. Winters like this one force political realities. We have to make societal decisions about what we value, and California is working out some really difficult choices.”

‘Managing our water resource isn't only about today’s drought’

Allan Fulton is a county-based extension irrigation and water resource adviser who covers Colusa, Glenn, Shasta and Tehama Counties in the northern Sacramento Valley, home to more than 2,000 farms, most of them orchards of almonds, walnuts, olives, and prunes.

Fulton’s job involves meeting and communicating by phone and email with farmers, conducting on-farm demonstrations, hosting workshops, writing for trade publications and newspapers, and conducting applied research in a number of areas, including ways to improve irrigation efficiency.

An example of his applied research: (VRI). While conventional irrigation systems dispense water uniformly over an entire area, VRI systems map the naturally varying soil types in a given orchard and design the irrigation system to deliver an optimum amount of water and fertilizer to each of the different soil zones.

“But managing our water resource isn't only about today’s drought,” says Fulton. “This year water is scarce, but other years we have more water than we know what to do with. The issue here is how to make better use of the excess water in years of high runoff and high snowpack.

“Most of the state’s storage reservoirs were built before 1970. Increasing surface water storage in an environmentally acceptable manner needs to remain among the management options, Fulton says.

“But it isn't the only option. We need to look more closely at groundwater banking in wet years, by capturing excess surface water and infiltrating it back into the ground. Measures that help stabilize groundwater in storage enable us to be better prepared when surface water is scarce.”

The 26-year extension veteran says there’s an urgent need for more applied research to help California’s vast agricultural economy adapt to changing resources and increasing attention.

“A big challenge is that over the past two to three decades we have greatly reduced investing in the the land-grant mission—investment in basic research and new knowledge, adaptive research to apply new knowledge to specific situations, and ultimately delivering new technology and information to address our society’s challenges,” Fulton says.

‘Reports of its demise are overstated’

Responding to reports that the current drought will drive much of California’s vegetable production to areas of the country where water is cheaper and more abundant, Tim Hartz, extension vegetable specialist with UC Davis for the past 22 years, and director of the state’s Vegetable Research & Information Center, says, “The idea that anything short of a cataclysm is going to make [vegetable production leave California] is ridiculous. Reports of its demise are grossly overstated.”


“Yes, we will have a substantial amount of fallowing this season, mostly lower-value annual crops, so that growers can maintain perennial crops,” he says. “And in the human context, the drought has and will continue to cause economic hardship, especially on the arid western side of the San Joaquin Valley, where we’ll have loss of supporting industries and huge unemployment.”


Long term, will agriculture rebound? Yes. We may lose some ground; output may shrink over time,” In the short term, ”we’ll be down some. Some items will be more expensive nationwide: peppers, squash, cantaloupe, leafy greens. With regard to nut crops, there may simply be less of these this year."


But, “Our processing-tomato production, and our multi-million dollar processing plants aren't going anywhere,” says Hartz.. “Leafy greens, melons, almonds and walnuts won’t disappear. They’ll be the last industries to go because they can’t be done on this scale, or at all, elsewhere.”


A lot of the prognostication is “based on the prospects that the current level of drought is permanent. But in the context of historical reality, we will have wet years. We haven’t a clue what the year 2100 will look like."


Learn more


U.S. Drought Monitor Continuously updating maps and information about drought conditions throughout the U.S.


NOAA's U.S. Seasonal Drought Outlook Latest seasonal assessment.


Managing California's Water: From Conflict to Reconciliation Explores solutions for a sustainable, long-term water strategy.


Virtual Tour of California Water A compilation of 15 videos explained by a series of experts from UC Davis describing the physical, legal and water management issues of the California Water Landscape.


California Water Map: Thirst Edition A bit of California water humor.


Advancing water resource management  in agricultural, rural, and urbanizing  watersheds: Why land-grant  universities matter. Incisive paper identifying challenges to managing the nation’s water resources for, especially as required for agricultural sustainability. Identifies knowledge gaps and suggests actions that harness the unique combination of expertise and public outreach/engagement of land-grant universities.


Progress with Groundwater Management in the Rural Counties of the Northern Sacramento Valley Detailed conference poster demonstrates Cooperative Extension’s role in helping people understand groundwater resources and long-range planning.

Released March 19,2014

Photo credit: California Department of Forestry and Fire Protection (CAL FIRE)

Writer: Peg Boyles, eXtension,



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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.