Thursday, July 18, 2013

Did you feel that shake?

We sure did here out in Sunol Valley at our construction sites!  A small earthquake struck on July 15, 2013 at 12:02 p.m., which measured at a 3.4 magnitude, according to the U.S. Geological Survey (USGS).

According to the USGS, the epicenter was located 7 miles east of Milpitas and 9 miles northeast of San Jose, at a depth of 5.3 miles below ground.  The earthquake was triggered by the Calaveras Fault. This active fault is located near to, or in some cases underneath, crucial water infrastructure in the Sunol Valley, including: the  existing Calaveras Dam,  the treatment plant that filters water from the valley for our customers, the pump station that transmits water to and from the plant, and the major pipelines that transmit water from the Sierra Nevada and the Alameda Watershed to our Bay Area customers.

Why does this matter?
This is a reminder to us why our work to seismically upgrade these crucial water transmission facilities through the Water System Improvement Program is so important.  We work every day to ensure that we can provide water to our customers within 24 hours after an earthquake.
·         We recently constructed a fourth seismically-designed pipeline that crosses the Calaveras Fault to survive after an earthquake
·         We completed seismic upgrades to the nearby San Antonio Pump Station
·         Upgrades to the Sunol Valley Water Treatment Plant are nearly complete.
·         Construction of the New Irvington Tunnel and a replacement Calaveras Dam are underway.

Our system is more reliable today than it was 10 years ago. And it will be much more reliable, still, 10 years from now.

We hope that the earthquake we are planning for never happens. But if it does, we will be ready!  To learn how to make yourself and your family ready, visit

Crews completed work on the Alameda Siphon #4 Project in 2010, which crosses directly over traces of the Calaveras Fault.

The New Irvington Tunnel will provide us a new 3.5 mile seismically upgraded tunnel.  Workers are seen here standing a set in the new tunnel and expect final tunnel hole-thru this Fall 2013 with completion at the end of 2014.

Calaveras Dam is being replaced to provide a new earth and rock fill dam restoring the historic storage capacity of the dam to 96,850 acre feet (31 billion gallons of water) and will withstand a credible earthquake from the Calaveras fault. 

During construction at the Sunol Valley Water Treatment Plant, crews drilled almost 1,200 piers underneath the new treated water reservoir to anchor it into the hillside in case of an earthquake on the nearby Calaveras fault.


Tuesday, July 9, 2013

Celebrating Summer at the Sunol Water Temple

With the sun shining, a soft breeze moving through the Valley and the Sunol Water Temple as the backdrop…. it was the perfect June afternoon in Sunol. For those who stopped by to join us, it was not only a chance to socialize with neighbors, but an opportunity to engage in lively conversations with SFPUC team members about the construction work in the Valley. Guests were able to play with rock samples from the Calaveras Dam, learn about future fire system upgrades for the town, marvel at historic photos of the Valley, check out a conceptual model of the proposed future Watershed Center, and even test their knowledge of the Valley by answering a trivia question to win a prize!

Thank you to those who were able to attend our summer open house! See you all around the Sunol Valley!

Wednesday, July 3, 2013

Calaveras Dam Project Continues to Dig Away

Today the Calaveras Dam workers celebrated yet another milestone since construction began in August 2011.  Over 3 million cubic yards of soils and rock have been excavated to make room for the replacement dam.  The team enjoyed lunch on top of one of the disposal sites, where they have moved and compacted nearly 20% of the 3 million cubic yards of materials. 

Imagine the weight of 96 fully loaded Titanic ships--- this is the approximate equivalent weight of the 3 million cubic yards of soils and rock that have been excavated and moved to disposal sites around the project. 

By the end of the project, the Calaveras Dam Replacement Project will have moved more than 9 million cubic yards of soils and rock.  About 3.5 million cubic yards of the materials will be used in the construction of the new dam, while the remainder will be disposed of onsite.  As we celebrate today, we still have a lot of heavy moving to look forward to!

Calaveras Dam workers are acknowledged by Earthwork Superintendent Sam Aiello for moving over 3 Million Cubic Yards

View of the Calaveras Dam foundation today
where major excavation has taken place to make room
for the future replacement dam