San Francisco Public Utilities Commission's Water System Improvement Program, Bay Division Pipelines 3 & 4 Crossovers Facilities Project, New Construction Methods and Focused Coordination Resulting in a Successful Project

The San Francisco Bay Area's primary water supply system, the Bay Division Pipelines, is highly vulnerable to seismic damage from the nearby San Andreas and Hayward fault zones. The San Francisco Public Utilities Commission's (SFPUC) $4.6B Water System Improvement Program (WSIP) consists of 81 projects to improve the seismic and delivery reliability to its customers. The Bay Division Pipelines (BDPLs 3 and 4) are two major SFPUC water transmission pressurized pipelines that extend 34 miles from Fremont to Redwood City in California, serving the heavily populated South Bay and southern Peninsula customers. BDPL 3 is a 72-inch diameter, welded steel and reinforced concrete pipe, depending on location. BDPL 4 is a 90-inch diameter, welded steel and pre-stressed concrete cylinder pipe, also depending on location. The BDPLs also convey the majority of San Francisco's water and replenish reservoirs in the Peninsula, enabling the SFPUC to meet peak summer demands.