The O'Shaughnessy Dam was completed in 1923, with the Tuolumne River flooding the Hetch Hetchy Valley. Restore Hetch Hetchy wants to drain the reservoir and restore the valley. Jim Wunderman, president and CEO of the Bay Area Council, which represents 275 Bay Area companies, told the San Jose Mercury News the court should "quickly dismiss this." He added: "Who needs a historic drought when there's a group that wants to tear down one of California's critical water storage and clean energy systems?"
Photo: Wikimedia Commons

This view of the Tuolumne River flowing through the Hetch Hetchy Valley was taken in 1908. Most of the 4 million annual visitors to Yosemite National Park aren't aware that the Hetch Hetchy Valley used to exit just 15 miles to the north. In its place is a reservoir that naturalists led by John Muir opposed in 1913 when the permitting passed. Muir's activism did pay off, however, when Congress passed the National Park Service Act in 1916.
Photo: Isaiah West Taber, Sierra Club Bulletin, Jan., 1908. Wikimedia Commons

On April 21, 2015, the environmental group Restore Hetch Hetchy (Oakland) filed a petition in the Superior Court in Tuolumne County claiming the Hetch Hetchy Reservoir in Yosemite National Park violates the water diversion mandates of the California Constitution.

Water from the Sierra Nevada via the Tuolumne River flows into the reservoir, supplying water for 2.6 million San Francisco Bay Area residents. The Restore Hetch Hetchy plan is to drain the 300-ft. deep reservoir (there is apparently little sediment behind the dam due to the granite rock of the Tuolumne watershed), expose the valley floor and replant native plants when the valley floor dries sufficiently. The group says the Tuolumne River would return to its natural course, and grasses and sedges would return on their own within a few years, with wildlife to follow. Restore Hetch Hetchy believes a dam should never have been built in Yosemite National Park, that the city of San Francisco basically appropriated the national park for its own purposes.

Restore Hetch Hetchy has been preparing this legal challenge for some time, saying the "occasion of John Muir's 177th birthday and the eve of Earth Day seemed like an appropriate time to file the petition."

The petition avers "the value of restoring Hetch Hetchy Valley is greater than the cost of making the water system improvements that would be necessary to move the point of diversion for Tuolumne River flows downstream of Yosemite National Park. As a result, continued operation of the reservoir is a violation of the prohibition against unreasonable methods of diversion in Article X, section 2 of the California Constitution."

Restore Hetch Hetchy references studies by the National Park Service, and the University of Wisconsin, which it says confirms the valley can be readily restored. The group notes it is "equally committed to ensuring a reliable water supply for San Francisco and other Bay Area communities. Therefore, our petition allows time for San Francisco to develop and implement a plan to assure that not one drop of water is lost and all hydropower is replaced with renewable sources."

In 2012, Restore Hetch Hetchy placed a measure on the San Francisco ballot that would have required the city to conduct an $8 million study of draining the reservoir, but it was soundly defeated.