Massive Machine Assembled to Dig First Tunnel Across San Francisco Bay

When one thinks of San Francisco Bay, one imagines its beautiful and not-so beautiful bridges spanning it. Tunnels in an active earthquake zone just don't seem to be the way the right approach to reach California's version of the Promised Land.

However, that perspective would be a mistaken one for utilities such as the area's water supply. Right now, the Bay Area is witnessing the beginning of a useful public works project involving the creation of the first-ever tunnel across San Francisco Bay. The Mercury News ran a story on the massive machine that will dig the ditch one hundred feet under the bottom of the bay. The dig will create a five-mile-long tunnel housing pipes for the San Francisco area's Hetch Hetchy water system. They will replace the current dual pipes, which are at risk of rupture in the event of a major seismic event. The photograph, from Jacobs Associates, the project's prime consultants, shows the area where the tunnel will be built.

If you thought the BART connection under the Bay, linking the City and the East Bay, was a tunnel, you would be mistaken. (I admit to being among the fooled.) The BART tracks are housed in a pre-constructed tube that sits on the bay floor, according to the Mercury News story.

For the Bay Area, this story is a big deal. I briefly lived in San Francisco, and I can appreciate how difficult it is to improve the area's infrastructure, and understand (as few East Coasters truly grasp) the impact of water and water rights in the West.

There's history in the pipeline story, as well, and not all of it is wonderful. In particular, the Hetch Hetchy dam, which provides the containment for the San Francisco peninsula's water supply, submerged a particularly lovely valley in Yosemite National Park.

Finally, there's the intersection of technology, hope, and necessity that the pipeline represents. It's an interesting story, even if one doesn't live in the Bay Area.