Truss Bridge, Cross-Bay Pipelines, Hetch Hetchy Aqueduct, Ravenswood, CA, 2025Pixels, pixels everywhere, but not a drop to drink, at flickr.com/photos/mattblaze/54#photography

A long, multi-section truss bridge crossing a body of water, carrying two large pipes rather than a road surface.
you are viewing a single comment's thread
view the rest of the comments
[–] [S] 1 point 1 year ago (9 children)

California's Hetch Hetchy Aqueduct, completed in 1936, delivers about 85% of the water used in the San Francisco Bay area. Originating over 160 miles away, at Yosemite's Hetch Hetchy reservoir, and working chiefly by gravity, a 21 mile section of two pipelines crosses the South Bay via a series of underground tunnels and bridges just south of the Dumbarton Bridge. This bridge section, near the end of its useful life, has recently been augmented by a deep tunnel.Infrastructure is heroic.

  • source
  • parent
  • hideshow 9 child comments
  • [–] [S] 1 point 1 year ago (4 children)

    The Hetch Hetchy water system was controversial from the start, pitting conservation (the reservoir is in a national park) against the need for clean and reliable urban water supplies. At the time of its construction, the fires from the 1906 great earthquake were still freshly in living memory, though organizations like the Sierra Club still opposed the project.

  • source
  • parent
  • hideshow 4 child comments
  • [–] 1 point 1 year ago

    @mattblaze the water from Hetch Hetchy is some of the cleanest and purest on the planet. Snowmelt held by granite. Few places have water that good (Granada, Spain is one). And the dam provides hydropower that serves a significant amount of the City of San Francisco's needs. It comes at a significant environmental cost, of course. As so many things do. On balance, was it the right thing to do? That's hard to answer, even in retrospect.

  • source
  • parent
  • [–] 1 point 1 year ago

    @mattblaze In 1988, Donald Hodel (Secretary of the Interior under Reagan) floated the idea of tearing down O’Shaughnessy dam, which inundated the Hetch Hetchy valley. At the time I thought it was an elaborate troll to split environmental groups away from local San Francisco interests, but apparently he was serious.sfgate.com/opinion/openforum/a

  • source
  • parent