About 20% percent of ACWD total distribution system water supply is purchased from the San Francisco Public Utilities Commission under an agreement which entitles ACWD to up to 13,400 acre feet of water per year. 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 (WSIP), approved October 31, 2008. The WSIP will deliver capital improvements aimed at enhancing the SFPUC's ability to meet its water service mission of providing high quality water to customers in a reliable, affordable and environmentally sustainable manner.
Calaveras Dam Project
The SFPUC's Calaveras Dam Replacement Project is currently under construction. The planned eight year project includes the construction of a new dam adjacent to the existing dam. To learn more please visit SFPUC's website.