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2 Geology 3 External links |
History
The valley was called Hetch Hetchy as early as the 1860s. The work means either acorns or edible seeds in the Native American Miwok language [1].
In 1903, San Francisco applied to the United States Department of the Interior to gain water rights to Hetch Hetchy. This provoked a 10-year environmental struggle with the Sierra Club. The environmentalist John Muir observed:
Construction of the dam was finished in 1923, but was later raised an additional 86 feet. Proponents of the dam said that the valley would be even more beautiful with a lake. Muir stated that this lake would deposit an unsightly ring around the lake, which exists today.
In 1987, the idea of razing the O'Shaughnessy gained an adherent from an unexpected quarter — Donald Hodel, then secretary of the Department of the Interior under President Ronald Reagan, once surprisingly advocated tearing down the dam
Nothing ever came of it; some people believe that Hodel had other political pretexts, to see residents of the left wing city of San Francisco coming out against an environmental issue — the mayor of San Francisco, Sen. Dianne Feinstein said in a Los Angeles Times story in 1987: "All this is for an expanded campground? ... It's dumb, dumb, dumb.
The Sierra Club is currently advocating removing the dam, but the city of San Francisco is resisting, because the reservoir is currently serving 2.4 million people, including parts of San Mateo County, Alameda County, and Silicon Valley. The cost of deconstructing the dam will be about 65 million dollars, which is a fraction of the 8 billion dollars needed to upgrade the water system of San Francisco. This dam is also a hydroelectric facility but the electrical generation equipment and lines are well-hidden.
Geology
Like Yosemite Valley, Hetch Hetchy was also sculpted by glaciers as recent as 10,000 years ago. The more recent glacier there was larger than the one in the paleo-Yosemite Valley. However, today the Hetch Hetchy area is drier.
On the upper portion of the valley beyond the reservoir there is evidence of relatively young lava flows. One recent flow formed the Little Devils Postpile which, as he name suggests, is a smaller version of the Devils Postpile near Mammoth Lakes to the south. Both formations are great examples of columnar jointing which is a phenomenon that results from contraction of basaltic lava as it cools (forming hexagonal columns).
