Camp Pendleton Marine Corps and Fallbrook Public Utility District, California, USA: Exploring indirect groundwater augmentation in the Santa Margarita River

Camp Pendleton, a US Marines Corps base in California, relies on the lower Santa Margarita River groundwater basin to provide drinking water for its occupants. It also provides water to the neighboring village, via the Fallbrook Public Utility District.

During dry years, natural streamflow and hence groundwater recharge is limited, but water demand remains the same. Some wastewater is recycled and used for irrigation and deck washing. However, there is a large volume of recycled water that is available for use, but currently discharged to the ocean at Oceanside Ocean Outfall.

This project will allow that excess recycled water to be used, by treating it to standards suitable for augmenting drinking water supplies, and recharging the Lower Santa Margarita River Basin. This will increase water security for both Camp Pendleton and Fallbrook by utilising local water instead of importing it from northern areas. This water reuse is crucial to withstand the challenges of climate change, while ensuring a safe and resilient water supply.