San Francisco Public Utilities Commission
Skip to page body Home Customer Service How To Environment Projects & Programs About Us


Calaveras Dam Replacement (WSIP)

Project Updates
Calaveras Road is open to the public, 7 days a week.

What’s New at Calaveras Dam?
To date, the Contractor has moved over six million cubic yards of earth and rock materials and started to construct the new dam. Crews have prepared disposal sites, completed grouting operations on the right abutment, and constructed a new intake tower and five adits (tunnels) which connect the outlet pipelines to the reservoir. We have also started building the upstream shell of the new dam and begun major excavation work on the new spillway. Over 22,000 cubic yards of concrete has been placed in the new spillway structure. Our teams work daily to protect the environment, to preserve the pristine watershed lands and natural habitats surrounding the project. As of December 2014, the Calaveras Dam Replacement Project was 66% percent complete.

In June 2012, we discovered unexpected geologic features during excavation of the left abutment area. These uncovered geologic features were not visible at the ground surface during the extensive geotechnical investigation work performed during the planning and design phases of the project. The findings have resulted in over 3 million cubic yards of additional material that needs to be moved in order to ensure the long-term stability of the slope during the performance life of the dam. Project completion is currently scheduled for late 2018.

Future Road Closure
A future 18 month road closure is scheduled to begin sometime in 2016 to haul materials to build the dam. During the closure, Calaveras Road will be CLOSED to vehicle, pedestrian, and bicycle traffic between Geary Road to the Alameda / Santa Clara County boundary, weekdays only. To stay updated, please join our road closure notification mailing list by emailing: or calling our 24 hour answer hotline at (866) 973-1476.

Road Safety Reminders:

  • Construction haul trucks are expected on Calaveras Road from 7:00 a.m. to 4:00 p.m. on Monday through Friday
  • Please drive slowly and bike safely on the narrow portions of Calaveras Road
  • Speed limit is 25 mph in construction zones
  • Bicyclists traveling in groups are encouraged to ride in single file, to share the road with oncoming trucks and vehicles
  • This affects the portion of Calaveras Road from the Alameda/Santa Clara County line to Highway 680 entrance in Sunol

Project Description
The project consists of building a new zoned earth and rock fill dam immediately downstream of the existing dam. The replacement dam will have a structural height of 220-feet high and is designed to accommodate a maximum credible earthquake on the Calaveras Fault. The dam will have a crest length of 1,210 feet, a base thickness of 1,180 feet, and crest thickness of 80 feet. The total volume of the dam will be approximately 3.5 million cubic yards. The replacement dam will restore the original reservoir capacity of 96,850 acre-feet, or 31 billion gallons of water. The storage is crucial to providing adequate water to our 2.6 million customers in the Bay Area.

Project Information

    August 2011
    November 2018
  • COST
    $718 Million

Additional Information

The information shown reflects the current forecast information published in the latest WSIP Quarterly Report.

Fact Sheets
Calaveras Dam Replacement Project
Fact Sheet - Winter 2015

Naturally Occurring Asbestos Information and Data:
- Air Monitoring Results

Environmental Impact Report:
- Calaveras Dam Replacement Project Final    Environmental Impact Report

- Calaveras Dam Replacement Project Final    Environmental Impact Report Addendum

- Calaveras Dam Replacment Project - Addendum to EIR July 2013

Summary Data Reports from Air Monitoring Events:
- August 2008 through August 2009
- September 2009 through July 2010
- August 2010 THROUGH November 2010


Need More Information? Contact:

Maria Le
Phone: (925) 493-4535 or

Betsy L. Rhodes
Phone: 415-554-3240 or

Sign up for our Sunol Valley Regional Projects blog to follow the projects in that area.