Comment Opportunity on Critically Overdrafted Groundwater Basins in California

The California Department of Water Resources (DWR) is updating the list of critically overdrafted basins in the state as part of its responsibilities under the new California groundwater management law, the Sustainable Groundwater Management Act of 2014.

The list of critically overdrafted basins and subbasins is open for comment through September 25, 2015. The draft list is online here, and the statewide map is posted here. Click on this link for more information and instructions on how to comment (scroll down to “Next Steps”).

A basin is considered to be critically overdrafted if existing water management practices would likely result in significant adverse overdraft-related environmental, social, or economic impacts.

The state made an initial list of eleven critically overdrafted basins in 1980, when DWR issued a report to the state legislature on groundwater basins in the state. Under the new groundwater law, DWR is required to update the list of critically overdrafted groundwater basins by 2017.

In late August, DWR released the draft list of critically overdrafted basins that includes nine newly identified basins. Of the newly listed basins, three of them are on the Central Coast and have been listed because of seawater intrusion: the Soquel Valley, 180/400 Foot Aquifer, and Los Osos Valley basins. The balance are in the San Joaquin Valley and Paso Robles. DWR has detected significant ongoing and irreversible subsidence (downward movement of the land surface) in the Merced, Delta-Mendota, and Westside basins.

Condition of basins from 1989-2009 was used to determine their status, as the law requires that the current drought period not be included in the evaluation.

Farms that are using groundwater from these critically overdrawn basins may have limits placed on their groundwater use in the future as the groundwater management process evolves. State law specifies that groundwater will be managed at the local level. The new groundwater management law will establish groundwater sustainability agencies in 2017 that will be tasked with developing groundwater management plans. Any mandated reductions in pumping will come from these local agencies rather than from DWR.

CCOF maintains a drought resources page that includes timely updates on the drought and links to programs that support farmers and ranchers during the drought. Visit CCOF’s drought resources page.