The Hetch Hetchy Valley, a V-shaped river canyon cut out by the ancestral Tuolumne River during the last glacial period between 110,000 and 10,000 years ago, is located in the northwestern part of California’s Yosemite National Park. It currently serves as a reservoir and a water supply system for irrigation and municipal interests, delivering water 167 miles west to the greater Bay Area of San Francisco. However, as recently as the late 19th century, the valley’s natural beauty was often compared to that of Yosemite Valley and was inhabited by Native Americans, who practiced subsistence hunting-gathering for some 6,000 thousand years prior to the arrival of settlers in the 1850s. The valley’s name may be derived from the Miwok word hatchhatchie, meaning “edible grasses” or “magpie”.
Before damming, the valley had an average depth of 1,800 feet and a maximum depth of over 3,000 feet. It also had a length of 3 miles and a width ranging from 1/8 to 1/2 mile and the valley floor was covered by roughly 1,200 acres of meadows fringed by pine forest. Kolana Rock, a massive rock spire to the south (at 5,772 feet), and Hetch Hetchy Dome, to the north (at 6,197 feet), roughly correspond to the locations of the Cathedral Rocks and El Capitan as seen from Tunnel View in Yosemite Valley. Wapama Falls (at 1,080 feet) and Tueeulala Falls (at 840 feet), both located in Hetch Hetchy Valley, are also among the tallest waterfalls in North America.
In 1906, after the major earthquake and subsequent fire that devastated San Francisco, the city applied to the U.S. Department of the Interior for the water rights to Hetch Hetchy. In 1908, President Theodore Roosevelt’s Secretary of the Interior, James R. Garfield, granted San Francisco the right to develop the Tuolumne River as a water source. As a result, a seven-year environmental struggle with the Sierra Club, an environmental group led by John Muir, followed.
Proponents of the dam replied that Hetch Hetchy had pristine water, a lack of development or private property, and the “perfect architecture for a reservoir”, with its steep-sided and flat-floored profile that would maximize the amount of water stored. Its narrow outlet would also serve as the ideal placement for a dam. Muir, however, predicted that the resultant lake would create an unsightly “bathtub ring” around its perimeter, caused by the water’s destruction of lichen growth on the canyon walls, which would be visible during low lake levels.
The battle over Hetch Hetchy Valley has continued until today, between those who wish to retain the dam and reservoir and those who wish to drain the reservoir and return the valley to its former glory. However, if this ever happens, a concerted effort would have to be made in order to control the introduction of wildlife and tourism back into the valley in order to prevent the destabilization of the ecosystem — a process that could take decades or even centuries!
- Visited: Oct 2011
- UNESCO: 1984