Hetch Hetchy

Before damming, the high granite formations produced a valley with an average depth of and a maximum depth of over ; the length of the valley was with a width ranging from . The valley floor consisted of roughly of meadows fringed by pine forest, through which meandered the Tuolumne River and numerous tributary streams. Kolana Rock, at , is a massive rock spire on the south side of the Hetch Hetchy Valley. Hetch Hetchy Dome, at , lies directly north of it. The locations of these two formations roughly correspond with those of Cathedral Rocks and El Capitan seen from Tunnel View in Yosemite Valley. A broad, low rocky outcrop situated between Kolana Rock and Hetch Hetchy Dome divided the former meadow in two distinct sections. Formerly, a "small but noisy" waterfall and natural pool existed on the Tuolumne River marked the upper entrance to Hetch Hetchy Valley, informally known as Tuolumne Fall (not to be confused with a similarly named waterfall several miles upriver near Tuolumne Meadows). The waterfall on the Tuolumne is now submerged under Hetch Hetchy Reservoir. Geology The Hetch Hetchy Valley began as a V-shaped river canyon cut out by the ancestral Tuolumne River. About one million years ago, the extensive Sherwin glaciation widened, deepened and straightened river valleys along the western slope of the Sierra Nevada, including Hetch Hetchy, Yosemite Valley, and Kings Canyon farther to the south. During the last glacial period, the Tioga Glacier formed from extensive icefields in the upper Tuolumne River watershed; between 110,000 and 10,000 years ago Hetch Hetchy Valley was sculpted into its present shape by repeated advance and retreat of the ice, which also removed extensive talus deposits that may have accumulated in the valley since the Sherwin period. At maximum extent, Tioga Glacier may have been long and up to thick, filling Hetch Hetchy Valley to the brim and spilling over the sides, carving out the present rugged plateau country to the north and southwest. When the glacier retreated for the final time, sediment-laden meltwater deposited thick layers of silt, forming the flat alluvial floodplain of the valley floor. Compared with Yosemite Valley, the walls of Hetch Hetchy are smoother and rounder because it was glaciated to a greater extent. This is because the Tuolumne catchment basin above Hetch Hetchy is almost three times as large as the catchment area of the Merced River above Yosemite, allowing a greater volume of ice to form. ==Flora and fauna==

, The Hetch Hetchy Valley, California, late 19th century Hetch Hetchy is home to a diverse array of plants and animals. Gray pine, incense-cedar, and California black oak grow in abundance. Many examples of red-barked manzanita can be seen along the Hetch Hetchy Road. Spring and early summer bring wildflowers including lupine, wallflower, monkey flower, and buttercup. Seventeen species of bats inhabit the Hetch Hetchy area, including the largest North American bat, the western mastiff. Before damming, the valley floor contained abundant stands of black oaks, live oak, Ponderosa pine, Douglas fir, and silver fir bordering the meadows, with alder, willow, poplar and dogwood in the riparian zone along the Tuolumne River. The valley's abundant plants provided nourishment for mule deer, black bears and bighorn sheep. Due to large cataracts on the Tuolumne River upstream, Hetch Hetchy Valley may have been in the uppermost range for native rainbow trout in the river. Due to its abundant wetlands and stream pools, Hetch Hetchy was notorious among early travelers for becoming infested with mosquitoes in the summertime. Said San Francisco resident William Denman in 1918, "The first time I went into the Hetch Hetchy the mosquitoes were intolerable. They would light upon a man's blue shirt and turn it brown, and were voracious as mosquitoes would be." ==History==

Indigenous peoples People have lived in Hetch Hetchy Valley for over 6,000 years. Native American cultures were prominent before the 1850s when the first settlers from the United States arrived in the Sierra Nevada. During summer, people of the Miwok and Paiute came to Hetch Hetchy from the Central Valley in the west and the Great Basin in the east. The valley provided an escape from the summer heat of the lowlands. They hunted, and gathered seeds and edible plants to furnish themselves winter food, trade items, and materials for art and ceremonial objects. Today, descendants of these people still use milkweed, deergrass, bracken fern, willow, and other plants for a variety of uses including baskets, medicines, and string. or "magpie". It is likely that the edible grass was blue dicks. became the first non-Native American to enter the valley. Local legend attributes the modern name Hetch Hetchy to Screech's initial arrival in the valley, during which he observed the Native Americans "cooking a variety of grass covered with edible seeds", which they called "hatch hatchy" or "hatchhatchie". Screech reported that the valley was bitterly disputed between the "Pah Utah Indians" (Paiute) and "Big Creek Indians" (Miwok), and witnessed several fights in which the Paiute appeared to be the dominant tribe. About 1853, his brother, Joseph Screech (credited in some accounts for the original discovery of the valley) By the 1880s, San Francisco was looking to Hetch Hetchy water as a fix for its outdated and unreliable water system. This provoked a seven-year environmental struggle with the environmental group Sierra Club, led by John Muir. Muir observed: with pristine water, lack of development or private property, a steep-sided and flat-floored profile that would maximize the amount of water stored, and a narrow outlet ideal for placement of a dam. which would inevitably be visible at low lake levels. Since the valley was within Yosemite National Park, an act of Congress was needed to authorize the project. The U.S. Congress passed and President Woodrow Wilson signed the Raker Act in 1913, which permitted the flooding of the valley under the conditions that power and water derived from the river could only be used for public interests. Ultimately, San Francisco sold hydropower from the dam to the Pacific Gas and Electric Company (PG&E), which led to decades of legal wrangling and controversy over terms in the Raker Act. The controversy over Hetch Hetchy was in the context of other political scandals and controversies, especially prevalent in the Taft administration. The Great Alaskan Land Fraud and the Pinchot-Ballinger Controversy caused both Richard A. Ballinger and Gifford Pinchot to resign and be fired respectively. The openings in the Taft administration led to the eventual success of the Raker Act. Work on the Hetch Hetchy Project began in 1914. The Hetch Hetchy Railroad was constructed to link the Sierra Railway with Hetch Hetchy Valley, allowing for direct rail shipment of construction materials from San Francisco to the dam site. Construction of O'Shaughnessy Dam began in 1919 and was finished in 1923, with the reservoir first filling in May of that year. The dam was then high; its present height of was achieved only later, in 1938. On October 28, 1934 – twenty years after the beginning of construction on the Hetch Hetchy project – a crowd of 20,000 San Franciscans gathered to celebrate the arrival of the first Hetch Hetchy water in the city. The Early Intake (Lower Cherry) Powerhouse began commercial operation five years before the O'Shaughnessy Dam was completed. The first Moccasin Powerhouse in Moccasin, California began commercial operation in 1925 followed by the Holm Powerhouse in 1960 (the same month the Early Intake Powerhouse was taken out of service). In 1967 the Robert C. Kirkwood Powerhouse started commercial operation followed by a New Moccasin Powerhouse in 1969 when the Old Moccasin Powerhouse was taken out of service. Finally, in 1988, a third generator was added to the Kirkwood Powerhouse. File:Hetch-Hetchy-dam-site.jpg|The narrow defile at the lower end of Hetch Hetchy Valley where San Francisco planned to dam the Tuolumne River, seen in 1914 before construction began File:O'Shaughnessy Dam in Yosemite NP.JPG|The same area seen today, with O'Shaughnessy Dam and Hetch Hetchy Reservoir Hetch Hetchy Reservoir.jpg|Hetch Hetchy Reservoir ==Hetch Hetchy Project==

Hetch Hetchy Valley serves as the primary water source for the City and County of San Francisco and several surrounding municipalities in the greater San Francisco Bay Area. The dam and reservoir, combined with a series of aqueducts, tunnels, and hydroelectric plants as well as eight other storage dams, comprise a system known as the Hetch Hetchy Project, which provides 80% of the water supply for 2.6 million people. The project is operated by the San Francisco Public Utilities Commission. The city must pay a lease of $30,000 per year for the use of Hetch Hetchy, which sits on federal land. The aqueduct delivers an average of of water each year, or per day, to residents of San Francisco and San Mateo, Santa Clara and Alameda Counties. An additional hydroelectric system comprising Cherry Lake, Lake Eleanor and the Holm Powerhouse is also part of the Hetch Hetchy Project, adding another 169 megawatts of generating capacity. After passing through the powerhouses, Hetch Hetchy water flows into the Hetch Hetchy Aqueduct which travels across the Central Valley. Just before reaching the Bay Area, it passes through the Irvington tunnel near the city of Fremont, and the aqueduct splits into four pipelines at . These are called Bay Division Pipelines (BDPL) 1, 2, 3, and 4, with nominal pipeline diameters of 60, 66, 78, and 96 inches (1.5, 1.7, 2.0 and 2.4 m, respectively). All four pipelines cross the Hayward fault. Pipelines 1 and 2 cross the San Francisco Bay to the south of the Dumbarton Bridge, while pipelines 3 and 4 run to the south of the bay. In the Bay Area, Hetch Hetchy water is stored in local facilities including Calaveras Reservoir, Crystal Springs Reservoir, and San Antonio Reservoir. The water quality is high because of the unique geology of the upper Tuolumne River drainage basin, which consists mostly of bare granite; as a result, the rivers feeding Hetch Hetchy Reservoir have extremely low loads of sediments and nutrients. The watershed is also strictly protected, so swimming and boating are prohibited at the reservoir (although fishing is permitted at the reservoir and in the rivers which feed it),{{cite web ==Proposed restoration==

The battle over Hetch Hetchy Valley continues into the 21st century between those who wish to retain the dam and reservoir, and those who wish to drain the reservoir and return Hetch Hetchy Valley to its former state. Arguments for Those in favor of dam removal have pointed out that many actions by San Francisco since 1913 have been in violation of the Raker Act, which explicitly stated that power and water from Hetch Hetchy could not be sold to private interests. Hydroelectric power generated from the Hetch Hetchy project is largely sold to Bay Area customers through a private power company, Pacific Gas & Electric (PG&E). San Francisco was able to accomplish this in 1925 by claiming it had run out of funds to extend the Hetch Hetchy transmission line all the way to the city. The terminus of the incomplete line was "conveniently located next to a PG&E substation", which connected to PG&E's private line which in turn bridged the gap to San Francisco. and that it might be decades or even centuries before the valley could be returned to natural conditions. Some observers, such as Carl Pope (director of the Sierra Club), stated that Hodel had political motives in proposing the study: to divide the environmental movement by seeing residents of the strongly Democratic city of San Francisco coming out against an environmental issue. Dianne Feinstein, the mayor of San Francisco at the time, said in a Los Angeles Times story in 1987: "All this is for an expanded campground? ... It's dumb, dumb, dumb." Karin Klein has described Yosemite Valley as "so crammed ... that it looks more like a ripstop ghetto than the site of a nature experience." However, she did support breaching the dam once it has reached the end of its lifespan rather than replacing it. which would have required the city to conduct an $8 million study on how the flooded valley could be drained and restored to its former state. The proposed study would also have been required to identify potential replacements for the water storage capacity and hydroelectric power production.{{cite web ==See also==

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