Designer rendering of future Cambrian tanks

Cambrian Reservoirs Replacement Project

Aerial view of Cambrian embankment reservoirs

San Jose Water’s Cambrian Station currently consists of two large earthen embankment reservoirs with storage capacity of 12.1 million gallons and 3.9 million gallons, respectively. The first reservoir was originally constructed in 1890 and the second in 1921. Both have reached the end of their useful life. 

San Jose Water is planning to start a multi-year construction project in May 2024 to build two new tanks — providing 16 million gallons of potable water storage to our customers. The reservoir replacement project is scheduled to be completed in September 2027.

The project involves: 
  • Demolishing and removing the existing reservoirs.
  • Performing earthwork to accommodate the new facilities.
  • Constructing two new 8-million gallon pre-stressed concrete water storage tanks.
  • Replacing portions of the inlet/outlet piping within the property boundary.
  • Tree removal to accommodate earthwork and foundations for the new tanks; replacement trees will be planted. 
  • Frontage improvements along S. Bascom Avenue, including street trees and sidewalk widening.
Why are the improvements necessary?
  • The existing reservoirs have reached the end of their useful life. The new tanks will have a more resilient structure with a long service life (100± years), lower maintenance requirements, and improved seismic stability.
  • Improved water quality due to installation of mixing systems in each tank.

During construction, you may also notice some additional noise related to the use of equipment necessary to demolish the existing reservoirs, move large quantities of earth, and construct two large concrete water storage tanks. After some initial earthwork, sound attenuating measures along the property boundary are planned as part of the project to ensure construction noise is consistent with the City’s policies. Work will be done Monday through Friday between the hours of 7:00 AM and 7:00 PM, in accordance with City of San Jose ordinances. 

Did you know?

The first pressurized zone in the City of San Jose became known as the Cambrian Zone — growing from approximately 9,000 residents in 1870 to over 225,000 residents. Today, Cambrian Zone encompasses much of the City’s downtown region. The new tanks at Cambrian Station will continue to serve this same area for generations to come.

Cambrian Reservoir construction in 1939

Check this page for updates as we work our way through the stages of this crucial infrastructure improvement project.