In this issue we take a look at the Water System Improvement Program (WSIP) being constructed by the San Francisco Public Utilities Commission. The WSIP was envisioned in the wake of the Loma Prieta earthquake in 1989 that caused widespread damage to the area. I can recall tuning in to watch the World Series between the San Francisco Giants and Oakland A’s when the quake happened, and listening as Al Michaels described the scenes in the aftermath, including a collapsed portion of the double-decked Bay Bridge and damage to areas downtown.
The WSIP is a $4.8 billion program that will increase the reliability and redundancy of the water system that serves 2.6 million people. The WSIP is the latest chapter in a long and interesting history of water delivery in the Bay Area. The water system stretches more than 160 miles from the Sierra Mountains to the San Francisco Peninsula and the City of San Francisco. In fact, the water supply — the Hetch Hetchy reservoir that was formed by damming the Tuolomne River — was created to provide a reliable source of water in the aftermath the Great Earthquake of 1906 that ravaged San Francisco. Without water to fight fires, the city burned for three days, resulting in even more catastrophic damage and loss of life.
The construction of the water system lasted more than 20 years, culminating with the arrival of Hetch Hetchy waters in the Crystal Springs Reservoir on the San Francisco Peninsula in 1934. The WSIP provides redundancy and seismic reliability to that system, and allows for maintenance and repair of some sections of the system that have not been taken out of service since becoming operational. The major tunneling components are: the 3.5-mile long New Irvington Tunnel, which parallels an existing tunnel which will be rehabilitated; the 5-mile Bay Tunnel, the first bored tunnel constructed under San Francisco, which replaces existing 1930s-era steel pipelines; and the 4,200-ft New Crystal Springs Bypass Tunnel, which provides seismic improvements by relocating an existing pipeline.
The Bay Tunnel and New Crystal Springs Bypass Tunnel projects are complete, with the New Irvington Tunnel expected to be in service by spring 2015. In fact, the Bay tunnel opening was commemorated by a ceremony at the Pulgas Water Temple in October, almost 25 years to the day of the Loma Prieta earthquake.
With the WSIP winding down, the tunneling community may not have far to go for the next big water project. The Delta Habitat Conservation and Conveyance Program, which begins in nearby Sacramento, involves some 70 miles of large diameter tunnels to support the delta ecosystem and secure water for some 25 million Californians and 3 million acres of farmland. If all goes to current plan – probably unlikely given some of the opposition to this massive $25 billion program — tunnel design would commence in early 2016, with the first tunnel contracts being advertised for construction bids in late-2017 to early-2018.
Stay tuned …