Calaveras Dam Team participates in the US Society on Dams Conference

Some of our Sunol Valley Project team members are visiting Colorado this week. And they are not visiting to see the snow, but taking part in the United States Society on Dams (USSD) 2016 Annual Conference representing the Calaveras Dam Replacement Project.

As you know, the Calaveras Dam Replacement Project is the largest project of the $4.8 billion Water System Improvement Program (WSIP) to repair, replace, and seismically upgrade key components of the Hetch Hetchy Regional Water System. 

Our WSIP Director Dan Wade and Calaveras Dam Project Manager Susan Hou were joined by the members of our SFPUC Engineering Management Bureau at the conference to present on the construction and challenges with the Calaveras Dam Replacement Project.

The completion of the project is important to the water supply for the Bay Area. Calaveras Reservoir, when full, represents nearly half of all the water storage in the Bay Area for the Hetch Hetchy Regional Water System that serves 2.6 million customers. Calaveras Reservoir is a crucial source of water supply during times of drought and when Hetch Hetchy Reservoir supplies are unavailable for any reason. 

Our project construction continues and we have moved over 7 million cubic yards of earth and rock materials to make room for the new dam. We plan to start constructing the replacement dam later this year. The project is over 70% complete.

From L to R: SFPUC Engineering Staff Carman Ng, Tedman Lee, Alisha Reinhardt, USSD President John Wolfhope, Former USSD Executive Director Larry Stephens, SFPUC WSIP Director Dan Wade and Calaveras Dam Project Manager Susan Hou

National Dam Safety Awareness Day

As construction continues at the Calaveras Dam Replacement Project, we take a moment to recognize May 31^st as National Dam Safety Awareness Day. Each year on May 31st, the nation remembers teh devastation that occurred on May 31, 1889 in Johnston, Pennyslvania when the South Fork Dam failed. This tragic event resulted in thousands of deaths and left many homeless. The Johnston disaster was the worst dam failure in the history of the U.S.

National Dam Safety Awareness Day reminds us of the importance of dam safety and preventing future failures. Dams provide many befefits such as water supply and storage, hydropower, recreation, flood prevention and improve wildflife habitats.

 

This also reminds us how critical and important our work is here in Sunol Valley to rebuild the Calaveras Dam. We are currently 66% complete and anticipate final completion of the dam in end of 2018.

The Calaveras Replacement Dam when complete will provide us:

·         The largest drinking water reservoir in the local Bay Area storing 31 billion gallons (96,850 acre ft) of water, providing more than half of the storage capacity for 2.6 million customers

·         A new seismically upgraded dam with a structural height of 220 feet, a crest length of 1210 feet and width of 80 feet at the crest and 1180 feet at the base

·         A new 1550 ft spillway and a new intake/outlet shaft tower which will convey water to and from the reservoir through a pipeline downstream and to our Bay Area customers

 

Aerial Photo of the Calaveras Dam Replacement Project
taken on May 21, 2015

 

 

Calaveras Dam Welcomes the US Society on Dams Conference

It is fitting that the SFPUC helped host the annual meeting of the United States Society on Dams (USSD) this last week in the same month as the anniversary of the 1906 Great Earthquake and Fire. The group finished their week of technical sessions and presentations on dam safety in extreme events with a field tour of a dam in construction.

That would be our very own Calaveras Dam Replacement Project. The project will construct a new seismically designed earth and rock fill dam right next to the existing, which will be able to withstand the maximum credible earthquake on the Calaveras fault.

The USSD Conference attendees peppered the Calaveras Dam Replacement Project Team with questions.  We appreciate that the SFPUC project team members, the Construction Management team from Black & Veatch, Design team from URS, and the contractor Dragados USA/Flatiron/Sukut Construction shared their experiences with their industry colleagues. 

Then the Calaveras Team returned to the current work at hand, which is continuing the major excavation work on the new spillway and stilling basin, as well as mechanical and electrical improvements to the new intake Tower.

When complete in late 2018, the replacement dam will enable us to bring the Calaveras Reservoir back to historic capacity, storing approximately half of the Hetch Hetchy Regional Water System’s local Bay area water supply.

This somber anniversary for the 1906 Great Earthquake reminds us to ensure our families are prepared for the next big earthquake. Visit 72hours.org, or http://www.redcross.org/ca/san-francisco/ to learn more. 

 SFPUC Project Manager Susan Hou discusses the critical upgrades to the Hetch Hetchy Regional Water System

Project Manager Alberto Benlloch from the joint venture of Dragados USA/Flatiron/Sukut Construction points out to the tour the excavation work to-date of over 4 million cubic yards of material

Aerial view taken on March 23, 2014