Reservoir 2B Replacement Project

Laguna Beach, CA

South Coast Water District's Reservoir 2B Replacement Project, led by Ardurra as the prime consultant and Peterson Structural Engineers (PSE) as the structural engineer of record, replaced an aging, seismically vulnerable 0.1 million-gallon steel reservoir with two modern 0.1MG AWWA D100 welded-steel tanks. Located on a steep, constrained hillside in South Laguna Beach's wildland-urban interface, the project required innovative engineering solutions to deliver critical fire protection and water infrastructure resilience.

Key Project Highlights:

• Designed two 24-foot-tall reservoirs with 33-foot inside diameters to the latest seismic provisions, fully anchored with hydrodynamic sloshing force analysis
• Engineered soil nail retaining walls up to 25 feet tall to stabilize slopes and expand site footprint
• Implemented a bent plate roof system, eliminating corrosion-prone crevices and improving long-term durability
• Integrated cathodic protection system to extend reservoir service life
• Provided built-in redundancy for uninterrupted service during maintenance
• Completed May 2025 under budget at $6.3 million (original estimate $6.7 million)
• Coordinated complex permitting, including Coastal Development requirements

The project advances South Coast Water District's Wildfire Mitigation and Fire Safety objectives, ensuring reliable drinking water and fire protection for a high-risk community. By introducing redundancy and applying advanced seismic design standards, the new system provides lasting resilience against earthquakes and wildfires while protecting rate payer investments through durable, low-maintenance infrastructure.

The project received a 2026 ACEC-California Engineering Excellence Commendation Award.