Friday, December 29, 2017

Happy New Year Photo Friday: A Year's Work

The start of any new year is a good time for reflection. For us here at the Calaveras Dam Replacement Project, we are reflecting on how much progress we have made in 2017. Below are two pictures of our project, one at the beginning of the year and one taken a couple weeks ago.

Calaveras Dam at the beginning of 2017:

We were months into building the dam itself, and the foundation, and outlet pipeline are still above ground.

Calaveras Dam in late 2017:

As you can see from the picture above, we made tremendous progress on construction of the replacement dam itself. The team is more than half way up with the building of the replacement dam, whose final grade you can see rising up more than 110 feet. The foundation and outlet pipe are completely buried now under the new dam.

To date, our project is 89% complete. Our New Year's goal is to have the entire project completed by mid-2019.

From all of us, we wish you and yours a Happy New Year!

See you around the valley!

Wednesday, December 27, 2017

Photo Tuesday at Sunol Valley Yard

Photo Tuesday at the Sunol CorporationYard

Today's post is about the SFPUC's Sunol Corporation Yard, which is located near the Sunol Water Temple.  In the last year, we have been constructing badly-needed upgrades to the Corporation Yard that is home to our Water Supply and Treatment East Bay operations and our Natural Resources personnel. 

Here are some photos of our progress.

Shop #5 will house plumbing and electrical supplies

Iron workers at the job site

The Sunol Yard Long-Term Improvements are expected to be completed by the end of 2018.  During construction, the Sunol Water Temple will be closed to the general public.

We hope you are having a wonderful Holiday Season.

See you around the Valley!

Friday, December 15, 2017

Piezometers and Inclinometers - Part 2

Piezometers and Inclinometers

This week’s blog is Part 2 of our instrumentation series. Piezometers and inclinometers are two types of internal instruments used to measure a dam’s movements. Both of these instruments will be installed in the new Calaveras dam.


A piezometer is an instrument that monitors the ground water through the dam’s core and into the downstream drainage blanket and downstream rock/soil shell. A piezometer helps to ensure that the ground water surface does not erode the toe of the dam (the bottom downstream part of the dam). It also helps track the water level in the underline bedrock foundation.

How Piezometers Work

An open stand-pipe piezometer is an open pipe (see picture above) that permits water to enter. The water level is measured and compared to other piezometers surrounding the dam’s face. These types of piezometers are called open-stand piezometers. We also have automated piezometers called Vibrating Wire Piezometers (VWP’s). VWP’s are data collection devices. We will have a total of 17 VWP’s and 14 open-stand pipe piezometers at Calaveras Dam.

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An inclinometer is an instrument that measures the movement of a slope with respect to gravity. Slopes on dams are built to be stable but still need to be monitored for possible movements. Inclinometers verify the stability of dams, dam abutments (sides) and upstream slopes during and after a reservoir filling.

How Inclinometers Work

Inclinometers measure the orientation angle of an object with respect to the force of gravity. This is done by means of an accelerometer, which monitors the effect of gravity on a tiny mass suspended in an elastic support structure. When the device tilts, this mass will move slightly, causing a change of electrical charge between the mass and the supporting structure. The tilt angle is calculated from the measured electrical charge. You will always find inclinometers in pairs or sometimes in 3’s. Two inclinometers placed at Calaveras Dam.

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Piezometers and inclinometers will play an important role in Calaveras. Once they are placed, they will need to be monitored and observed on a frequent basis.

See you around the valley!

Friday, December 8, 2017

Calaveras Road Closure Extended to September 30, 2018

The closure of Calaveras Road to thru traffic between Milpitas and Sunol has been extended to September 30, 2018. The road has been closed on weekends and holidays because of a land slide that undermined the road within the closure section. 

We anticipate the road to reopen on weekends sometime in 2018. Please check our website at for current information regarding the closure and for upcoming information regarding the reopening of the road during the weekends.

Once complete, the Calaveras Dam Replacement Project will increase the reliability of the water supply for East Bay residents and businesses.

We sincerely apologize for any inconvenience this may cause you and greatly appreciate your patience and support as we upgrade the regional water system.

If you have any further questions, feel free to call our toll-free 24 hour answer line at (866)-973-1476. Email us at: or

See you around the valley!