Justin Brandt (Former Employee)

In areas adjacent to the Delta-Mendota Canal (DMC), extensive groundwater withdrawal from the San Joaquin Valley aquifer system has caused areas of the ground to sink as much as 10 feet, a process known as land subsidence. This could result in serious operational and structural issues for the Delta-Mendota Canal (DMC). In response, the USGS is studying and providing information on groundwater...

Subsidence is a global problem and, in the United States, more than 17,000 square miles in 45 States, an area roughly the size of New Hampshire and Vermont combined, have been directly affected by subsidence. More than 80 percent of the identified subsidence in the United States is a consequence of human impact on subsurface water.

The East Bay Municipal Utility District (EBMUD) has proposed to store and recover as much as 10 million gallons of water per day (MGD) at an aquifer storage and recovery (ASR) site, the Bayside Groundwater Project. Water will be stored in a 100-ft sequence of coarse-grained sediment (the "Deep Aquifer") underlying the East Bay Plain and the adjacent Niles Cone ground-water basin.

The San Joaquin Valley is one of the most productive agricultural regions in the nation. Beginning around the 1920's, farmers relied upon groundwater for water supply. Over time, overpumping caused groundwater-level declines and associated aquifer-system compaction and land subsidence that resulted in permanent aquifer-system storage loss.

The U.S. Geological Survey's National Water-Use Information Program compiles the nation's water-use data at the county, state, and national levels. USGS five-year reports on national and state water-use estimates between 1950-2015 are posted on the web at: https://water.usgs.gov/watuse/. USGS water-use data for states and counties for 1985-2015 are available at: https://waterdata.usgs.gov/nwis/wu.

In 2010, Californians withdrew an estimated total of 38 billion gallons of water per day, compared with 46 billion gallons per day in 2005.