Which California crops use the most water?


When discussing the drought, the question of which crops use the most water comes up a lot.

A Pacific Institute analysis of California Department of Water Resources data sheds light on the state’s top 10 water-intensive crops in 2015, the most recent year for which the department has published water-use estimates. The department grouped crops into 20 categories when reporting water-use data.

On average, California crops used 2.97 acre feet of water per acre that year, the data show. An acre foot is equal to about 326,000 gallons, or enough water to cover an acre of land 1 foot deep.

The analysis ranked pasture first among California’s top 10 most water-intensive crops, in some cases grouped by categories (in average acre feet of water applied per acre in one growing season), followed by nuts and alfalfa:

  1. Pasture (clover, rye, bermuda and other grasses), 4.92 acre feet per acre
  2. Almonds and pistachios, 4.49 acre feet per acre
  3. Alfalfa, 4.48 acre feet per acre
  4. Citrus and subtropical fruits (grapefruit, lemons, oranges, dates, avocados, olives, jojoba), 4.23 acre feet per acre
  5. Sugar beets, 3.89 acre feet per acre
  6. Other deciduous fruits (applies, apricots, walnuts, cherries, peaches, nectarines, pears, plums, prunes, figs, kiwis), 3.7 acre feet per acre
  7. Cotton, 3.67 acre feet per acre
  8. Onions and garlic, 2.96 acre feet per acre
  9. Potatoes, 2.9 acre feet per acre
  10. Vineyards (table, raisin and wine grapes), 2.85 acre feet per acre

Many people also question how much water cannabis takes to grow. The Department of Water Resources didn’t track water usage for cannabis in its 2015 data, but The Washington Post reported in 2015 that the crop uses 1.4 acre feet per acre.

Roughly 40% of California’s water use is agricultural, according to Josue Medellin-Azuara, a director at the UC Davis Center for Watershed Sciences.

In analyzing agricultural water use during a drought, it’s important to consider the economic benefits of growing crops, Medellin-Azuara said in an interview.

In a report published this month by californiawaterblog.com, “Jobs and Irrigation During Drought in California,” Medellin-Azuara and Jay Lund, also a director at UC Davis Center for Watershed Sciences, wrote that “fruits, nuts and vegetables support most agricultural gross revenues, employment and income in California’s agriculture.”

Using Department of Water Resources data, they found that “nearly 85% of all employment and revenues are from growing fruits, nuts and vegetables, which are about half of California’s irrigated acreage.”

“Growing water scarcity for agriculture is probably best managed using water markets and pricing so the industry and the state can make the most of limited supplies,” Medellin-Azuara and Lund wrote in the report.

“Efforts to impose detailed arbitrary limits on crops and regions are unlikely to serve the economic and environmental interests of California,” the report said, “but rather further impoverish rural areas and distract from discussions needed for long-term progress.”

You can reach Staff Writer Matt Pera at matthew.pera@pressdemocrat.com. On Twitter @Matt__Pera.


Read More: Which California crops use the most water?