Groundwater Well Levels (IMAGE) Arizona State University Caption Groundwater well levels dropped several meters at most of the 1600 observation wells across the Central Valley, from 2007-2010. These observations are strongly associated with groundwater extraction during the drought. Credit ASU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.