Building Seismic Resilience into a Regional Water System

The Metropolitan Water District of Southern California (Metropolitan) provides approximately 1.4 billion gallons of water every day to 19 million people over a 5,200 square miles service area within southern California. Metropolitan’s system includes the 242-mile Colorado River Aqueduct, 830 miles of conveyance and distribution pipelines and tunnels, 20 dam and reservoir facilities, and 5 water treatment plants. The system traverses an area with numerous faults capable of generating large earthquakes that have the potential to impact water deliveries. Moreover, as an owner and operator of a critical lifeline system, Metropolitan has long recognized the importance of preparing for earthquakes and the associated seismic hazards. Accordingly, the organization has taken steps to improve the seismic resilience of the system to limit the impacts on water deliveries to our customers. Metropolitan employs a defense-in-depth approach for its seismic resilience strategy with the goal of preparing for and effectively responding to seismic events. The major components of this strategy include maintaining adequate emergency water supplies, hardening facilities to limit damage from seismic hazards, and maintaining a robust emergency response program. This paper will describe the implementation of Metropolitan’s seismic resilience strategy, focusing on how the activities support the organizations goals for seismic resilience.