Challenge: To meet the high water supply demands of Southern California by maximizing the use of the Central and West Coast Groundwater Basins.

Solution: As part of a team of engineering consultants, INTERA helped the Water Replenishment District of Southern California (WRDSC) and Los Angeles Department of Water and Power (LADWP) apply a regional approach to identifying existing and potential new local water sources, treatment facilities, and replenishment and extraction locations capable of providing up to 40 MGD. Potential water sources include recycled water from the Hyperion Water Reclamation Plant, Leo Vander Lans Advanced Water Treatment Facility, and the Los Coyotes Water Reclamation Plant. Work included screening system components and developing implementable, complementary projects that can be initiated upon completion of the Master Plan. As part of the planning and feasibility assessment effort, INTERA is leading the hydrogeologic and groundwater modeling analyses to evaluate hydrogeologic constraints and locations/capacities of injection/extraction facilities. To accomplish this, we are using a suite of models including a state-of-the-art USGS unstructured grid model of the LA Coastal Plain and a refined groundwater model (developed by INTERA) of the area straddling the LA and Orange County boundary.

Results: INTERA’s efforts have helped ensure the projects included in the Master Plan are feasible from economic, hydrogeologic, engineering, and stakeholder perspectives. This Plan will ultimately reduce reliance on imported water, increase regional water supply reliability, maximize use of local groundwater supplies, and reduce ocean discharges through increased reuse.