Joseph Serna, LOS ANGELES TIMES
California’s San Joaquin Valley continues to sink at an alarming rate because of groundwater pumping and irrigation, according to a new study by NASA. Ground levels in some areas have dropped 1 to 2 feet in the last two years, creating deeper and wider “bowls” that continue to threaten the vital network of channels that transport water across Southern California, researchers say.
The findings underscore the fact that even as record rain and snow have brought much of California out of severe drought, some parts of the state will probably struggle with water problems for years to come.
Despite a new series of storms that battered California this week, state water regulators decided Wednesday to maintain drought restrictions for at least a few more months as they continue to assess recovery.
Researchers said subsidence has long been a problem in parts of California. “But the current rates jeopardize infrastructure serving millions of people,” said William Croyle, acting director of the state Department of Water Resources. “Groundwater pumping now puts at risk the very system that brings water to the San Joaquin Valley.”
Subsidence occurs when water is removed from underground aquifers and the surrounding soil collapses on itself. Even if the underground water is replenished, subsided basins can’t hold as much water as they did previously.