Hydroelectric Energy

Hydropower is the use of water to power machinery or make electricity. Anyone who has listened to the rushing streams of the Sierra Nevada mountains or stood in the surf of the Pacific Ocean knows the power of moving water. In addition to age old technologies like dams and water wheels, new technologies like run-of-river hydropower and wave energy devices, can help us harness the power of moving water, or “hydrokinetic energy,” to produce clean, renewable energy without major impacts on wildlife and water quality.

The San Francisco Public Utilities Commission powers almost all municipal facilities and operations, from City Hall to MUNI, with hydroelectric power generated at the Hetch Hetchy reservoir in Yosemite. In addition to providing clean drinking water to San Franciso, the Hetch Hetchy system generates 1.6 billion kilowatt-hours (kWh) of clean, hydroelectric power annually for the City and County of San Francisco’s municipal tenants and retail customers as well as additional energy for residents and businesses in the 662 square-mile service area of the Modesto and Turlock Irrigation Districts. The gravity-driven water and clean hydropower deliveries of the Hetch Hetchy system ensure that San Francisco and regional customers receive water and power delivered by a greenhouse gas-free system. No additional energy is required to move this water across the state, thus the system results in lower regional conventional energy purchasing.

For more information, visit the San Francisco Public Utilities Commission.

Additional Information for Hydroelectric Energy

Hetch Hetchy Water & Power System, Tuolumne Co. Historical Society
John Muir referred to the Hetch Hetchy Valley when first seeing it in 1871 as "Tuolumne Yosemite."
Clean Hydroelectric Energy, SF Public Utilities Commission
The City and County of San Francisco and our other retail and wholesale power customers are extremely fortunate to receive their energy from the Hetch Hetchy Water and Power System.
Hetch Hetchy Water & Power System, SF Public Utilities Commission
Hetch Hetchy Reservoir was formed on the Tuolumne River after construction of O'Shaughnessy Dam in 1923. The reservoir can store up to 117 billion gallons of drinking water.