Excessive groundwater pumping has resulted in significant overdraft of 21 basins across the state. Most are in the Central Valley.
It’s led to low water levels, saltwater intrusion, or subsidence, where the land above the basin sinks.
The list was last updated in 2003. Lauren Hersh, with the California Department of Water Resources, says in determining the list, the department considered groundwater conditions in wet and dry years, but not during the drought.
“There is an acknowledgement that those basins that were having troubles, most likely conditions have gotten worse,”says Hersh.
Hersh says new laws passed in 2014 will require agencies that use water from those basins to come up with a plan to manage them by 2020.