Local groundwater has always been an integral component of the Los Angeles Department of Water and Power’s (LADWP) water supply portfolio, comprising approximately 15 percent of the supply during normal years and up to 30 percent in drought years. Local groundwater has also been heavily relied upon in the event of emergencies, such as the 1994 Northridge Earthquake, when the more routine delivery systems were temporarily disrupted.

The LADWP has entitlements or water rights in four separate local groundwater basins: San Fernando, Sylmar, Central, and West Coast (see pie chart below). The San Fernando Groundwater Basin (SFB) is the largest of these resources, accounting for nearly 80 percent of all local groundwater pumped by LADWP. The Upper Los Angeles River Area Watermaster oversees the groundwater activities for the San Fernando and Sylmar Basins, while the Central and West Coast Basins are within the jurisdiction of the State Department of Water Resources. While local groundwater has historically provided Los Angeles with a high-quality, reliable water supply, existing groundwater contamination in the SFB has impacted LADWP’s ability to fully utilize this valuable resource. LADWP is advocating strongly for the various regulatory agencies to identify and hold the responsible parties accountable for cleaning up the SFB. LADWP is also pursuing a parallel track to explore other administrative or legal remedies available to expedite cleanup, including the pursuit of monetary compensation for water lost due to contamination and the resulting pumping limitations.

The LADWP’s Groundwater Management Program will be gradually increasing its capital investments over the next 10 years, primarily focusing on projects that increase groundwater recharge and well production, and improve groundwater quality in the SFB. A key study that is currently being conducted by an outside consultant is the Groundwater System Improvement Study which involves, among other things, an evaluation of the groundwater quality in the SFB and recommendations for treatment options to maximize the utility of the groundwater supply. In addition, LADWP is investigating opportunities for increased storage of groundwater in the local basins, creating a cost-effective, environmentally friendly reserve of water resources in cases of extreme drought or other emergencies.