From the air, scientists map ‘fast paths’ for recharging California’s groundwater aquifers by car
California’s ground water, like the state’s other water, is not a reserve, but rather a resource that can be tapped for recreation, agriculture or commerce.
Yet with limited supply and growing demand, many of our most precious drinking and irrigation aquifers have become so depleted that they are now nearly depleted in some parts of the state. The situation in Northern California is especially dire.
To keep pace with growing demand for the state’s available water, a new study released on Aug. 24 provides a new glimpse into what may be driving the groundwater “fast path” to total depletion – an increase in agricultural production rates that takes water away from aquifers, or from other uses.
“[The study] has shed a whole new light onto how groundwater is being used right now,” said Jim Rauch, a professor emeritus of geochemistry and chemical oceanography at Stanford University and the study’s co-author.
The study’s findings suggest that the water may only be sustainable if the increased production of crops, such as almonds, is paired with an increase in agricultural production in other ways.
“It’s not enough just to increase crop production, or to just increase irrigation use,” said Rauch. “You have to look at all these additional non-crop uses as well.”
The issue is not new, nor is it confined to California. For more than a century, the Western United States has experienced a steady increase in agricultural production, driven by the conversion of natural lands to farm land and the expansion of food production through new technologies and innovations, such as high-yield crops adapted to regional climate and soil conditions. But over the last five decades, water use has increased dramatically, especially through increased demands for irrigation and for increased use of fertilizer and pesticides, Rauch and his co-author, William C. Sargent of the U.S. Geological Survey, have shown in several studies.
Although California has seen a significant increase