Hetch Hetchy Valley

Hetch Hetchy This photograph, taken in the early 1900s before the O'Shaughnessy Dam was constructed, shows the Hetch Hetchy Valley and the Tuolumne River, looking east. Wapama Falls is on the left, Kolana Rock on the right. Floor elevation 3,800 feet (1,200 m) Geography Coordinates 37°56′51″N 119°47′13″W A modern photo, taken from much the same vantage point, shows the submergence of the valley floor under the waters of the reservoir.

Hetch Hetchy Valley is a glacial valley in the northwest corner of Yosemite National Park in California. It is currently completely flooded by O'Shaughnessy Dam, forming the Hetch Hetchy Reservoir. The Tuolumne River fills the reservoir. Upstream from the valley lies the Grand Canyon of the Tuolumne. The reservoir supplies the Hetch Hetchy Aqueduct. The damming of the valley in the 1920s, and the creation of a reservoir, were at the time, and since, a major environmental controversy in the Western United States.

The Hetch Hetchy Road drops into the valley at the O'Shaughnessy Dam, but all points east of there are roadless, and accessible only to hikers and equestrians. Wapama Falls 1,700 feet (520 m) and Tueeulala Falls 840 feet (260 m), both among the tallest waterfalls in North America, are both located in Hetch Hetchy Valley.

History

The name "Hetch Hetchy" comes from a grass with edible seeds that grows in the valley, in the Native American Sierra Miwok language. It was first used in the English language by Joseph Screech, who in 1850 became the first European to enter the valley. Screech noted that Paiutes had inhabited Hetch Hetchy and still gathered seeds, roots and acorns in and around it. Acorns are indeed available in the valley, but rare elsewhere in the high country.

Hetch Hetchy Little Arroyo in 1908 signed C.N. Doughty

Charles F. Hoffmann of the California Geological Survey conducted the first survey of the valley, in 1867.

Damming

See also: O'Shaughnessy Dam

In 1906, after a major earthquake, San Francisco applied to the United States Department of the Interior to gain water rights to Hetch Hetchy. This provoked a seven-year environmental struggle with the environmental group Sierra Club, led by John Muir. Muir observed:

Dam Hetch Hetchy! As well dam for water-tanks the people's cathedrals and churches, for no holier temple has ever been consecrated by the heart of man.

Tueeulala Falls on the north side of the valley.

Proponents of the dam replied that the valley would be even more beautiful with a lake. Muir correctly predicted that this lake would deposit an unsightly ring around its perimeter, which would be visible at low water.

Because the valley was within Yosemite National Park, an act of Congress was needed to start the project. The federal government ended the dispute in 1913, with the passage of the Raker Act, which permitted flooding of the valley.

Construction of the dam was finished in 1923. Water from the dam serves 2.4 million Californians in San Francisco, San Mateo, and Alameda Counties, as well as some communities in the San Joaquin Valley, and generates electricity for San Francisco. Environmental groups (including the Sierra Club and Restore Hetch Hetchy) advocate removing the dam.

Geology

Like nearby Yosemite Valley, Hetch Hetchy was sculpted by glaciers as recently as 10,000 years ago, though the Hetch Hetchy glacier was more recent and larger than the one in the paleo-Yosemite Valley. 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 the name suggests, is a smaller version of the Devils Postpile near Mammoth Lakes to the southeast. Both formations are excellent examples of columnar basalt, a phenomenon that results from contraction of basaltic lava as it cools (forming hexagonal columns). Similar formations are found in the Giant's Causeway in Ireland, and the New Jersey Palisades in the United States, as well as other places throughout the world.

Proposed restoration

Recent proposals, first by the U.S. Department of Interior and subsequently by the California state government, to remove the dam and restore the valley raise the possibility that the valley may once again be returned to its natural condition (see Restore Hetch Hetchy). However, former Secretary of the Interior Don Hodel recalled in a 2005 op-ed that his proposal in the 1980s had been "met by an unexpected firestorm of opposition from some people who normally favored environmental responsibility and conservation, most notably then-mayor of San Francisco, Dianne Feinstein".

See also

• Tuolumne River
• Grand Canyon of the Tuolumne
• O'Shaughnessy Dam
• San Francisco Water Department
• Yosemite National Park
• Timeline of environmental events
• Hetch Hetchy Railroad
• The National Parks: America's Best Idea

References

• Simpson, John W. (2005). Dam!: Water, Power, Politics, and Preservation in Hetch Hetchy and Yosemite National Park. ISBN 0-375-42231-5. 
• Righter, Robert W. (2005). The Battle over Hetch Hetchy: America's Most Controversial Dam and the Birth of Modern Environmentalism. ISBN 0-195-31309-7. 

External links

• John Muir on Hetch Hetchy Dam
• Restore Hetch Hetchy web site
• Sierra Club on Hetch Hetchy
• Discover Hetch Hetchy - Environmental Defense
• San Francisco Public Utilities Commission, Department of Hetch Hetchy Water and Power
• U.S. Geological Survey Hetch Hetchy images - About 30 are available, from both before and after the construction of the dam.
• Hetch Hetchy Early Native American People's History
• California Resources Agency Hetch Hetchy Restoration Study