By Bettina Boxall, Los Angeles Times

These days, there’s a lot of discussion of carbon footprints. A new study by the Pacific Institute focuses on another footprint, that of water.

The report, released this month by the Oakland-based think tank, takes a look at the amount of water required to produce the goods Californians consume, whether it’s the food we eat or the things we buy; whether they are produced in state or imported from other states or foreign countries.

California’s total water footprint is about 64 million acre-feet, or 20 trillion gallons of water, per year, according to the study. More than half of that is used to produce goods that are imported and consumed here.

On a per capita basis, the average Californian’s water footprint is 1,500 gallons a day – slightly less than the average American’s but significantly more than the average in other developed countries.

Only about 4 percent of the total footprint is tied to direct household use, much of it for watering lawns and gardens. Industrial products, such as clothing and electronics, account for another 3 percent.

The biggest piece by far – 93 percent — is tied to agricultural production, both food that is imported from out of state or grown, produced and consumed in state. (California’s agricultural exports are not counted.) Thanks to the large amounts of water required to grow animal feed, meat and dairy products have an especially big footprint.

Overall, about 70 percent of the state’s water footprint is associated with goods produced elsewhere in the U.S. or in foreign countries.

“These findings suggest that California’s economic and social well-being is intimately connected with water resources beyond our borders and is vulnerable to water-supply constraints in those regions,” note authors Julian Fulton, Heather Cooley and Peter Gleick.