Wednesday, October 22, 2014

Calaveras Dam: Grouting in Numbers

What is grout? 
Most folks are likely familiar with using household grout for bathroom tiling work. Grout is a construction material commonly used to connect sections of concrete, fill voids, and seal joints. Grout is generally a mixture of water, cement, sand, and sometimes fine gravel.

How does it work for the dam?
The grouting operations are extremely important for the construction of the new replacement Calaveras Dam. Underneath the dam, we have designed a “grout curtain”. A grout curtain is a barrier that protects the foundation of a dam from water seepage and is used to strengthen the foundation of the dam. Essentially, the grout curtain fills cracks and fissures in the rock and works to control seepage and water flow. Our crews mix the grout onsite and inject the grout holes of the dam foundation. Holes are three inches in diameter and can reach up to a depth of 164 feet. Depending on the rock formation, the amount of injected grout used may differ.

Grouting Numbers Today
Over 589 holes have been grouted in the foundation. We have drilled almost 13 miles of grout holes. We have injected over 2.9 million pounds of cement grout into the foundation of the new dam.. How much grout is that? It is equivalent to approximately the same weight as 1,600 1967 model Volkswagen Beetles!

Grouting Operation taking place on the left abutment of the dam

Diagram of Grout Curtain – Calaveras Dam Replacement Project

Thursday, October 16, 2014

Sunol Valley: Getting Prepared – Seismic Upgrade Work Continues

Much has already been done as mentioned in our last post, but more important work lies ahead in Sunol Valley.  Our teams continue critical work to seismically upgrade our infrastructure. As we remember the Loma Prieta earthquake this week, here are some highlights on our ongoing projects:

New Irvington Tunnel Project
The new tunnel will provide a seismically upgraded connection between water supplies from the Sierra Nevada Mountains and the Alameda Watershed to Bay Area customers. It will extend 3.5 miles and have an internal diameter of approximately 8.5 feet. Final completion is expected in mid-2015.

Calaveras Dam Replacement Project
Work continues to build a replacement dam that will be seismically safe and restore the Calaveras reservoir to its historic capacity. The reservoir provides half of the Hetch Hetchy Regional Water System’s local Bay Area water storage. To date, over 5 million cubic yards of materials have been excavated and major work is being done on the new spillway. 
Final completion is expected end of 2018. 

San Antonio Backup Pipeline Project
The San Antonio Backup Pipeline (SABPL) project will include several new facilities and improvements in the Sunol Valley to help provide for the reliable movement of Hetch Hetchy water for planned and emergency discharges under future conditions. Completion is expected in March 2015.

We are extremely proud of our hard working teams in Sunol Valley, helping all of us become better prepared for the next earthquake. For more info, please contact us at our 24 hour answer line 866-973-1476.

Tuesday, October 14, 2014

Sunol Valley: Getting Prepared

This week we acknowledge the 25th Anniversary of the Loma Prieta Earthquake. On October 17, 1989 at 5:04 p.m, the magnitude 6.9 Loma Prieta earthquake, also known as the “World Series Quake,” lasted 15 seconds causing an estimated $6-10 billion in property loss in the Bay Area. The anniversary is a reminder to all of us to make efforts to be prepared for the next major earthquake.

Here’s a quick snapshot of what’s been done in the Sunol Valley to better prepare us:

San Antonio Pump Station – Completed
The San Antonio Pump Station is one of the key facilities in the Sunol Valley which pumps Hetch Hetchy water through a transmission pipeline to the San Antonio Reservoir to the Sunol Valley Water Treatment Plant. It serves as a critical seismic upgrade project which provides a reliable water supply to our Bay Area customers after a major earthquake.

Sunol Valley Water Treatment Plant – Completed
If the Hetch Hetchy water supplies become unavailable for any reason, this plant enables us to supply the minimum demand of water to our customers, especially those in the East Bay and South Bay. The plant can now provide 160 million gallons of water per day for up to two months in case of an emergency. Previously, that level of service would run out after only a matter of days.

Alameda Siphon No. 4 – Completed
This project will ensure the water system performs properly, and water can be delivered to customers after an earthquake. The Alameda Siphon No. 4 Project extends approximately 3,000 feet from the Alameda East Portal across both the Calaveras Fault and Alameda Creek to the Alameda West Portal. It consists of a seismically-designed thicker-walled pipe in the fault rupture zone, and a tunnel crossing under Alameda Creek. 

Friday, October 10, 2014

Water Conservation Top of Mind at Sunol Glen Walk-a-Thon

For many years the Sunol Glen School Walk-a-Thon has been a source of wet, outdoor fun for hundreds of students during the school’s annual fundraising event.  The staff at Sunol Glen School have already performed water efficiency audits at school to reduce their water use.  But during one of the driest years on record, school staff and the San Francisco Public Utilities Commission (SFPUC) kept water conservation top of mind at last week’s walk-a-thon.

The SFPUC provided water coolers to hydrate the students ranging from pre-school to eighth grade as they circled the track to raise money for the school.  Sunol Glen staff, volunteers, and even the students were well aware of the drought and were mindful to take only as much water as needed to fuel their efforts, even as temperatures soared above 90 degrees that day.

The school even held off on watering their field, so they could water the grass while spraying the sweaty students with a well-earned shower of water from the hose. This is one innovative way that the school is conserving water while preserving the school tradition that kids look forward to!!

It was a fun-filled day in Sunol as the students supported their school!  Go Eagles!

To help us beat the drought, please visit for resources and information about how you can conserve.

Sunol Glen Spirit Squad kicked off the walk-a-thon festivities.

Friday, October 3, 2014

Town of Sunol Fire Suppression System Project

Construction Update

Railroad Crossings:
On Monday, October 6, 2014 crews will start the jack and bore work to cross under the Alameda County Rail Road at the intersection of Main Street, Kilkare Road, and West Foothill Road. If work proceeds as planned, the contractor will begin the jack and bore work underneath the Union Pacific Railroad on Main Street the week of October 20, 2014. This means construction at both railroad crossings will occur at the same time.

What to Expect:
* Crews will insert a steel casing from the driving pit at the intersection of West Foothill and Kilkare Road to a receiving pit (next to the Depot Parking lot).

* Kilkare Road will be reduced to one-lane traffic during daytime at the railroad crossing. We appreciate your patience with the expected traffic delays in the area.

* Access through the area will be allowed at all times, but please prepare for delays.

* Crews might need to hand drill under the railroads to remove rocks. The equipment will generate some noise.

Bridge Crossings:
Next week, crews will complete all work related to the bridge crossings at Sinbad Creek on Bond Street as well as on Foothill Road.

Hydrant Installation:
The majority of the hydrants will have been installed at their marked locations by the end of October. There is one hydrant on Main Street that will not be installed until after the jack and bore work is completed. The hydrants should be available for use in November.

As always, please do not hesitate to contact us with any questions, comments, or concerns. The 24-hour Answering Line: (866) 973-1476 or or

Thank you for your patience!