A new study shows land in California’s San Joaquin Valley has been sinking at record-breaking rates over the last two decades as groundwater extraction has outpaced natural recharge. The researchers found that the average rate of sinking for the entire valley reached nearly an inch per year between 2006 and 2022.  Researchers and water managers have known that sinking, technically termed “subsidence,” was occurring over the past 20 years. But the true impact was not fully appreciated because the total subsidence had not been quantified. This was in part due to a gap in data. Satellite radar systems, which provide the most precise measure of elevation changes, did not consistently monitor the San Joaquin Valley between 2011 and 2015. The Stanford researchers have now estimated how much the land sank during these four years. 

Related groundwater articles:

• Communications Earth & Environment: Study: Quantification of record-breaking subsidence in California’s San Joaquin Valley
• Scientific Reports: Study: Groundwater resources: challenges and future opportunities
• Capital Public Radio: As monumental California water law turns 10, state leaders say there’s a lot left to do
• E&E News by POLITICO: California regulators back off planned groundwater crackdown
• Kronick blog: Counties update groundwater well-drilling restrictions in response to the Governor’s termination of executive orders