The drought in 2021 taught California a new lesson in water management. Rising spring temperatures and drought-parched ecosystems allowed less water to flow into reservoirs. Now another lesson is emerging: San Joaquin Valley crops need an additional one million acre-feet of water to stay cool in the heat.

“Those are big numbers,” said Josh Viers, a civil and environmental engineering professor at UC Merced, after describing the net water loss from an additional 2.5 inches of evapotranspiration demand spread across five million acres of irrigated farmland in the valley.

Plants need that water to replace moisture lost through evaporation in the soil and through a process similar to breathing, known collectively as evapotranspiration.

Viers was speaking at a recent meeting of the State Board of Food and Agriculture and describing the results of an upcoming study. The findings add to a string of new insights that the Public Policy Institute of California (PPIC) has incorporated into a policy brief for state leaders that details the drought’s impacts to agriculture and outlines steps the state can take to help farmers adapt.

PPIC will host a panel discussion on the topic on Thursday with a community water liaison in Gov. Gavin Newsom’s office alongside a Sacramento Valley rice farmer and the general manager of a local irrigation district in the San Joaquin Valley.

According to the brief, general water evaporation is already a significant issue in California. Temperatures in 2021 soared nearly 3.5 degrees above the 20th century average, creating an additional 3-4 inches of evaporative demand and leading to about an 8% increase in crop water demands.

josh viersUC Merced Professor Josh Viers

That water loss will be especially painful this year, as the impacts of three dry years ripple through the agriculture industry and rural communities.

Last year water deliveries for Central Valley and North Coast farms dropped by about 5.5 million acre-feet, more than 40% below the historical average, according to PPIC. Groundwater pumping increased by more than four million acre-feet, raising energy bills by $184 million. While subsidence increased due to the pumping, it was at a lower rate than during the 2012-16 drought.

Statewide, about 400,000 acres of farmland went fallow. The Russian River basin and grape growers bore the brunt of the impacts, amounting to $148 million in losses—nearly a quarter of the annual revenue. The San Joaquin River and Tulare Lake basins saw minimal losses at around 1%.

Many of the same authors on the policy brief published a report in February showing the drought led to the loss of $1.1 billion and nearly 9,000 jobs in California agriculture, with the broader economic impacts stretching to $1.7 billion and 14,600 jobs.

While surface water deliveries were lower in 2021 than any time during the previous drought, state and federal agencies have already zeroed out Central Valley Project and State Water Project allocations this year for many growers, leading the researchers to believe the impacts will intensify and spread this year.

“Definitely the San Joaquin Valley will suffer more cutbacks this year compared to last,” UC Merced Professor Josué Medellín-Azuara told the food and agriculture board, adding that reservoir levels are lower than last year and groundwater sustainability plans will restrict additional pumping in some areas.

Medellín-Azuara, who is an author on the PPIC brief, is working on a separate report that will consider the implications of fallowing farmland for the food processing and beverage industries. His lab is also examining disparities in the average costs of water for irrigated agriculture.

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Citrus growers were able to stay afloat last year by working with exchange contractors to transfer water from the Sacramento Valley through the Sacramento–San Joaquin Delta to orchards in the San Joaquin Valley, according to Casey Creamer, president and CEO of California Citrus Mutual. But it came with “huge costs,” sometimes at 400% more than the typical price.

“We don't know that we're going to have that ability this year,” said Creamer. “That's a very significant concern.”

He noted the drought comes at a challenging time for the industry. The organization surveyed its members in early 2020, before the pandemic, and found the average cost to grow navel oranges was $3,300 per acre. A year later it was $3,900 and, adding in additional packing and shipping costs, it was up by about $1,000 an acre. Creamer believes it has now jumped to $4,500 per acre due to skyrocketing costs for fuel, fertilizer and transportation.

To help farmers adapt to the drought, the PPIC researchers recommend several policy changes. They suggest local groundwater agencies incentivize farmers to avoid pumping in areas that could impact drinking water or to replace wells at risk of running drying. Measures like these would help farmers who are reliant on groundwater pumping and indirectly help maintain local economies.

Groundwater recharge projects would add more storage capacity during wet years, and the state could support this through upgrades to storage and conveyance structure along with improvements to reservoir management, according to PPIC.

The report offers other policy options for building drought resilience over longer timespans, such as placing caps on groundwater pumping and encouraging farmers to balance perennial with annual crops, allowing more flexibility for fallowing during dry years. The state could also boost its $50 million in funding for repurposing fallowed farmland to provide environmental and community benefits.

“This is the new normal, folks,” said Viers, in describing a 20-year dry run in California that is spliced with just three wet years. “Unfortunately, we're going to have to change how we do business. We're seeing nibbling on the edges, but we need big changes in how we approach this.”

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