California’s agriculture is the most productive in the country. But it also drinks up about 80% of the developed water used in the state. 

How much water is used by farms changes with the weather from year to year. But it remained generally flat between the 1980s and 2015. 

“The only real way to reduce water use further in agriculture is to grow less food and farm products, or take more agricultural land out of production,” said Danny Merkley, water resources director with the California Farm Bureau Federation.

Almonds and pistachios are the fourth most water-intensive crops in California, after rice, alfalfa and irrigated pasture, according to the Pacific Institute. Nut acreage has soared in the past 10 years, but what that means for water is less clear: State data lags and there’s no real-time monitoring of agricultural water use.

More changes are coming, with climate change parching crops and state law calling for sustainable groundwater management. Complying with California’s Sustainable Groundwater Management Act could require 500,000 to 1 million acres of prime agricultural land to come out of production in the San Joaquin Valley, according to The Public Policy Institute of California.  

The state has earmarked $110 million over three years to repurpose agricultural land and put it towards other uses, such as groundwater recharge and habitat restoration. Other funding is provided to growers who fallow their fields.

Growers also could opt for crops grown during the rainy season and breed more drought-tolerant varieties. And leaving crop residues in fields and reducing tillage can allow soil to retain more water.  

More efficient irrigation systems help, too. But the Farm Bureau’s Merkley said making water go farther is growing more difficult and smaller growers can struggle to pay for it. Also, an international team of researchers warned that increased efficiency must be accompanied by robust monitoring and caps on water extractions. Otherwise, they wrote, it can backfire by prompting planting of more acreage with more water-intensive crops.