The Raker Act of 1913 granted the City and County of San Francisco water and power resource rights-of-way in Yosemite National Park and Stanislaus National Forest and required the City to generate hydroelectric power through the Hetch Hetchy system. The Raker Act also requires the City to sell excess Hetch Hetchy power at cost, when available above the City’s own municipal needs, to Modesto and Turlock Irrigation Districts for agricultural pumping and municipal needs. The SFPUC sells Hetch Hetchy power, in excess of its Raker Act obligation to Modesto and Turlock Irrigation Districts and its own municipal needs, to public agencies and/or private commercial users.
The power system delivers an average of 1.7 billion kilowatt hours of electricity annually to the City and County of San Francisco, the Modesto and Turlock Irrigation Districts and tenants at the San Francisco International Airport. Municipal agencies, departments and enterprises consume slightly more than half of the electricity that is produced by the Hetch Hetchy power system or purchased from other suppliers.
Generation from the Hetch Hetchy power system is used first to provide power to the City. Among the City agencies that receive electricity from the SFPUC are the San Francisco Municipal Railway, San Francisco General Hospital, Laguna Honda Hospital, the San Francisco Unified School District, and the SFPUC’s regional and local water and clean water systems. These electric loads are expected to increase over the next decade. The hydroelectric power is produced in two ways:
- as water flows by gravity from the Hetch Hetchy reservoir through two hydroelectric plants on its way to the Bay Area; and
- as water is released from Lake Eleanor and Cherry Lake, two SFPUC reservoirs located in the vicinity of Hetch Hetchy reservoir.
Lake Eleanor water is released and flows to Cherry Lake. Water is released from Cherry Lake generating power through Holm powerhouse, a hydroelectric plant, as it flows into the Tuolumne River via Cherry Creek. Cherry and Eleanor reservoirs are used to supply water for additional hydroelectric generation and river flow for the Tuolumne. In addition to hydroelectric power generation, the SFPUC also operates a small gas-fired power plant located at the Southeast Water Pollution Control Plant.
