Hetch Hetchy Valley
Encyclopedia
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...
in Yosemite National Park
Yosemite National Park
Yosemite National Park is a United States National Park spanning eastern portions of Tuolumne, Mariposa and Madera counties in east central California, United States. The park covers an area of and reaches across the western slopes of the Sierra Nevada mountain chain...
in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. It is currently completely flooded by O'Shaughnessy Dam
O'Shaughnessy Dam
The O'Shaughnessy Dam is a curved gravity dam on the Tuolumne River in the Hetch Hetchy Valley of California's Sierra Nevada. The dam is located in Yosemite National Park, and creates the Hetch Hetchy Reservoir. It is named for former San Francisco chief engineer and the original chief engineer of...
, forming the Hetch Hetchy Reservoir
Hetch Hetchy Reservoir
Hetch Hetchy Reservoir is a reservoir in Yosemite National Park, about northeast from the city of Merced, California. The reservoir has a capacity of and is formed by the concrete gravity O'Shaughnessy Dam in Hetch Hetchy Valley on the Tuolumne River...
. The Tuolumne River
Tuolumne River
The Tuolumne River is a California river that flows nearly from the central Sierra Nevada to the San Joaquin River in the Central Valley...
fills the reservoir. Upstream from the valley lies the Grand Canyon of the Tuolumne
Grand Canyon of the Tuolumne
The Grand Canyon of the Tuolumne is the portion of the valley of the Tuolumne River in Yosemite National Park, USA. As defined by the United States Geological Survey, it begins immediately below Tuolumne Meadows and ends immediately above Hetch Hetchy Valley.The Tuolumne River runs as a somewhat...
. The reservoir supplies the Hetch Hetchy Aqueduct
Hetch Hetchy Aqueduct
The Hetch Hetchy Aqueduct is a conveyance of Tuolumne River water runoff from federal lands in Yosemite National Park to San Francisco and its client municipalities in the greater San Francisco Bay Area...
. 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.
History
The name "Hetch Hetchy" comes from a grass with edible seeds that grows in the valley, in the Native AmericanNative Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
Sierra Miwok
Valley and Sierra Miwok
The Plains and Sierra Miwok , were the largest group of Miwok Native American people...
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.
Charles F. Hoffmann
Charles F. Hoffmann
Charles Frederick Hoffmann was a German-American topographer working in California U.S. from 1860 to 1880.-Life:Hoffmann was born in Frankfurt, Germany, 1838. After receiving an education in engineering, he emigrated to America. In 1857 he was topographer for Frederick Lander’s survey to the Rocky...
of the California Geological Survey
California Geological Survey
Although it was not until 1880 that the California State Mining Bureau, predecessor to the California Geological Survey, was established, the "roots" of California's state geological survey date to an earlier time...
conducted the first survey of the valley, in 1867.
Damming
In 1906, after a major earthquake1906 San Francisco earthquake
The San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, California, and the coast of Northern California at 5:12 a.m. on Wednesday, April 18, 1906. The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.9; however, other...
, San Francisco applied to the United States Department of the Interior
United States Department of the Interior
The United States Department of the Interior is the United States federal executive department of the U.S. government responsible for the management and conservation of most federal land and natural resources, and the administration of programs relating to Native Americans, Alaska Natives, Native...
to gain water rights to Hetch Hetchy. This provoked a seven-year environmental
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....
struggle with the environmental group Sierra Club
Sierra Club
The Sierra Club is the oldest, largest, and most influential grassroots environmental organization in the United States. It was founded on May 28, 1892, in San Francisco, California, by the conservationist and preservationist John Muir, who became its first president...
, led by John Muir
John Muir
John Muir was a Scottish-born American naturalist, author, and early advocate of preservation of wilderness in the United States. His letters, essays, and books telling of his adventures in nature, especially in the Sierra Nevada mountains of California, have been read by millions...
. 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.
Because the valley was within Yosemite National Park
Yosemite National Park
Yosemite National Park is a United States National Park spanning eastern portions of Tuolumne, Mariposa and Madera counties in east central California, United States. The park covers an area of and reaches across the western slopes of the Sierra Nevada mountain chain...
, an act of Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
was needed to start the project. The federal government ended the dispute in 1913, with the passage of the Raker Act
Raker Act
The Raker Act was an act of the United States Congress that permitted building of the O'Shaughnessy Dam and flooding of Hetch Hetchy Valley in Yosemite National Park, California. It is named for John E. Raker, its chief sponsor...
, 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
Restore Hetch Hetchy
Restore Hetch Hetchy is a grassroots non-profit organization seeking to restore the Hetch Hetchy Valley in Yosemite National Park to its original condition.-History:...
) advocate removing the dam.
Geology
Like nearby Yosemite ValleyYosemite Valley
Yosemite Valley is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of California, carved out by the Merced River. The valley is about long and up to a mile deep, surrounded by high granite summits such as Half Dome and El Capitan, and densely forested with pines...
, 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
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
flows. One recent flow formed the Little Devils Postpile
Little Devils Postpile
Little Devils Postpile, in Yosemite National Park in California, United States, is a set of columnar joints in a basalt plug resembling the Devils Postpile formation. It is located along the Tuolumne River a few miles west of Tuolumne Meadows.-See also:...
which, as the name suggests, is a smaller version of the Devils Postpile near Mammoth Lakes
Mammoth Lakes, California
-History:The European history of Mammoth Lakes started in 1877, when four prospectors staked a claim on Mineral Hill, south of the current town, along Old Mammoth Road. In 1878, the Mammoth Mining Company was organized to mine Mineral Hill, which caused a gold rush. By the end of 1878, 1500 people...
to the southeast. Both formations are excellent examples of columnar basalt, a phenomenon that results from contraction of basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
ic lava as it cools (forming hexagonal columns). Similar formations are found in the Giant's Causeway
Giant's Causeway
The Giant's Causeway is an area of about 40,000 interlocking basalt columns, the result of an ancient volcanic eruption. It is located in County Antrim on the northeast coast of Northern Ireland, about three miles northeast of the town of Bushmills...
in Ireland, and the New Jersey Palisades
New Jersey Palisades
The Palisades, also called the New Jersey Palisades or the Hudson Palisades are a line of steep cliffs along the west side of the lower Hudson River in northeastern New Jersey and southern New York in the United States. The cliffs stretch north from Jersey City approximately 20 mi to near...
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 HetchyRestore Hetch Hetchy
Restore Hetch Hetchy is a grassroots non-profit organization seeking to restore the Hetch Hetchy Valley in Yosemite National Park to its original condition.-History:...
). 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
Dianne Feinstein
Dianne Goldman Berman Feinstein is the senior U.S. Senator from California. A member of the Democratic Party, she has served in the Senate since 1992. She also served as 38th Mayor of San Francisco from 1978 to 1988....
".
See also
- Tuolumne RiverTuolumne RiverThe Tuolumne River is a California river that flows nearly from the central Sierra Nevada to the San Joaquin River in the Central Valley...
- Grand Canyon of the TuolumneGrand Canyon of the TuolumneThe Grand Canyon of the Tuolumne is the portion of the valley of the Tuolumne River in Yosemite National Park, USA. As defined by the United States Geological Survey, it begins immediately below Tuolumne Meadows and ends immediately above Hetch Hetchy Valley.The Tuolumne River runs as a somewhat...
- O'Shaughnessy DamO'Shaughnessy DamThe O'Shaughnessy Dam is a curved gravity dam on the Tuolumne River in the Hetch Hetchy Valley of California's Sierra Nevada. The dam is located in Yosemite National Park, and creates the Hetch Hetchy Reservoir. It is named for former San Francisco chief engineer and the original chief engineer of...
- San Francisco Water DepartmentSan Francisco Water DepartmentThe San Francisco Water Department is an agency in San Francisco that provides water service to residents of the San Francisco Bay Area. The San Francisco Water Department privately holds substantial amounts of undeveloped land in many parts of the San Francisco Bay Area.Since the mid-19th century...
- Yosemite National ParkYosemite National ParkYosemite National Park is a United States National Park spanning eastern portions of Tuolumne, Mariposa and Madera counties in east central California, United States. The park covers an area of and reaches across the western slopes of the Sierra Nevada mountain chain...
- Timeline of environmental eventsTimeline of environmental eventsThe timeline lists geological, astronomical, and climatological events in relation to events in human history which they influenced. For the history of humanity's perspective on these events, see timeline of the history of environmentalism...
- Hetch Hetchy RailroadHetch Hetchy RailroadThe Hetch Hetchy Railroad was a standard gauge Class III railroad constructed by the City of San Francisco to support the construction and expansion of the O'Shaughnessy Dam across Hetch Hetchy Valley....
- The National Parks: America's Best IdeaThe National Parks: America's Best IdeaThe National Parks: America's Best Idea is a 2009 documentary film for television, DVD and companion book by director/producer Ken Burns and producer/writer Dayton Duncan which features the United States National Park system and traces the system's history...
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