Water Supply

Your water travels all the way from Yosemite to get to your tap. Unlike other sources of water, which rely on energy-intensive pumping systems, Hayward's water travels mostly downhill using the force of gravity. Hayward buys its water from the Hetch Hetchy Regional Water System, which is managed by the San Francisco Public Utilities Commission.

Water Supply

  1. Snow melts into the Hetch Hetchy Reservoir. Hayward is fortunate to have some of the purest water in the state.
  2. The water is released down the O'Shaughnessy Dam and continues to flow downhill through three hydroelectric powerhouses, including the Moccasin Powerhouse. The combined total hydroelectric output for these facilities is over 400 megawatts.
  3. The water flows downhill through the central valley by the force of gravity.
  4. Water is disinfected initially at the Tesla Portal Water Treatment Facility and is later treated at the Sunol Treatment Plant. The Tesla Treatment Facility is California’s largest ultraviolet (UV) water disinfection facility.
  5. The water flows under the Sunol Range through the Irvington Tunnel.
  6. The water flows from the SFPUC system to Hayward through two pipelines - a 24” pipeline that travels down Mission Blvd and a second a 42” pipeline that travels down Hesperian Blvd. The two pipelines are looped so the entire City has redundant water supply lines.
  7. The water is then pumped up to a series of reservoirs and pump stations known as the Highland Chain to supply water to the homes and businesses in the Hayward Hills.

Maitland Reservoir in Hayward

Hetch Hetchy Water System - Legendary Past, Visionary Future
This video gives an overview of the Hetch Hetchy Water System, which provides water for Hayward and other parts of the Bay Area. It recounts the beginnings of the system following the 1906 earthquake and has some great footage of old San Francisco.