A report released today by California's Pacific Institute estimates that reasonable water conservation improvements on the state's farms could save a huge amount of water--far more than what farmers have been forced to relinquish to protect fish habitat during the state's ongoing drought. The amount that could be saved, 1.8 trillion gallons annually, is more than 15 times the size of the municipal supply of San Francisco.
The report, Sustaining California Agriculture in an Uncertain Future, provides considerable ammunition to environmentalists in their fight with farmers over the West's dwindling water resources. In the midst of the third year of drought in California, growers are blaming endangered species laws for crimping their water supply and contributing to $1 billion in lost revenue this season. Though they've used their plight to call for weakening environmental regulations and building more dams and reservoirs, the report suggests their efforts are misplaced. Smarter conservation has allowed some growers "to increase their income, crop yields, and production, even during drought," says Pacific Institute president Peter Gleick. "Such success stories offer the state a vision of what a healthy agricultural future might look like."
The water conservation methods that the Gleick studied are already in use in the state, though many farmers cling to older practices. For example, 60 percent of crops in California are still irrigated by flooding the field, even though drip irrigation methods can easily halve water use. The report also suggests that farmers apply less water to crops during drought-tolerant growth stages and use sensors that can detect when soil is dry.
These ideas can seem far-removed from our lives until we realize that the products we consume account for more than 90 percent of our daily water use, far more than what comes out of our taps. I explore this idea in "What's Your Water Footprint," a piece in the current issue. The Pacific Institute and other environmental groups eventually hope the concept of a water footprint will catch on much as carbon footprints have. The idea could be used to reward farmers who do the right thing, either with tax breaks, loans, or a premium for the products they sell.
The case for looking at carbon footprints and water footprints together is stronger than ever. A new study from the University of Colorado found that climate change creates a 50 percent chance that the reservoirs supplied by the Colorado River, the West's main water source, could run dry by 2057. And a study released today by UC Davis found that California's $10 billion fruit and nut industry is under threat from higher temperatues, which could make it impossible to grow walnuts, pistacios, peaches, apricots, plums, and cherries almost everywhere in the Central Valley. If that happens, all the water conservation technology in the world probably won't save us.