From 2008 to 2010, pumping resulted in groundwater-level declines approaching historical lows and also renewed compaction. This has reduced the flow capacity of irrigation canals and resulted in structural damage totaling millions of dollars.
Recently published satellite data reveal rapid subsidence (i.e. sinking) of land in California’s Central Valley that spans more than 1,200 square miles, E&E Publishing reports.
The culprit is the pumping of groundwater for agricultural and urban uses, which occurred amid persistent drought and surface-water restrictions. In places, subsidence occurred at a rate of nearly 1 foot per year between 2008 to 2010, the period covered in the U.S. Geological Survey report.
The Bureau of Land Reclamation commissioned the report ahead of investing as much as $800 million to perform restoration along the San Joaquin River. "We may have the least [groundwater regulation] of any state," Felicia Marcus, head of the State Water Resources Control Board, tells E&E. "It's probably a tie with Texas at the state level."