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.

Sunol Valley: Getting Prepared

This week we acknowledge the 25^th 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.