A new report by the state of California estimates it would cost from $3 billion to nearly $10 billion to remove the 405-MW Hetch Hetchy water and hydroelectric project and restore the project site in Yosemite National Park.
In response to environmentalist pressure, the California Department of Water Resources and the Department of Parks and Recreation studied removing San Francisco’s water and power project — which helps supply 2.4 million Californians — in order to return the Hetch Hetchy Valley to a pristine condition.
Water Resources Secretary Mike Chrisman responded to a 2004 legislative request, directing the departments to summarize 20 years of Hetch Hetchy restoration studies by other organizations. Although there have been numerous studies, the report, released July 19, found major information gaps still exist.
The report said it appears technically feasible to restore Hetch Hetchy Valley, but existing information is not detailed enough to determine the financial feasibility of restoring the valley.
The report considered various aspects of restoration, including removal of the project’s O’Shaughnessy Dam, which was completed in 1923. It states restoration costs would depend on factors such as replacement of water and power supplies, method of dam removal, and restoration activities.
It estimates the cost of modifying or removing O’Shaughnessy Dam to be $250 million to $915 million, contributing to an estimated total restoration cost of $3.061 billion to $9.889 billion.
It adds that if a decision is ever to be made, policymakers and the public will need significantly more detailed quantitative information about costs, benefits, and tradeoffs associated with a specific proposal.
The report makes no formal recommendation about next steps, as Hetch Hetchy Valley is part of a national park and not under state control. It said further investigations into Hetch Hetchy restoration must be shaped by the participation of the federal government and entities such as the San Francisco Public Utilities Commission, tribes, and the public.