San Francisco Regional Water System

The Supply

About 20% percent of ACWD total distribution system water supply is purchased from the San Francisco Public Utilities Commission. This supply is predominantly from the Sierra Nevada, delivered through the Hetch-Hetchy aqueducts, but also includes treated water produced by the SFPUC from its local watersheds and facilities in Alameda and San Mateo Counties.

The amount of imported water available to the SFPUC's retail and wholesale customers is constrained by hydrology, physical facilities, and the institutional parameters that allocate the water supply of the Tuolumne River. Due to these constraints, the SFPUC is very dependent on reservoir storage to firm-up its water supplies.

Water System Improvement Program

In order to enhance the ability of the SFPUC water supply system to meet identified service goals for water quality, seismic reliability, delivery reliability, and water supply, the SFPUC has undertaken the Water System Improvement Program. To learn more, please visit SFPUC's Water Infrastructure Improvements.

Calaveras Dam Project

The SFPUC's Calaveras Dam Replacement Project was completed in June 2019. To learn more please visit SFPUC's website.

Watch a time lapse video of the SFPUC moving 7 million cubic yards (!) to make way for the Calaveras Dam.