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!

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.

Piezometers

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.

Image courtesy of http://www.briodydrilling.ie/services-monitoring.asp

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.

Image curteosy of http://www.slopeindicator.com

Inclinometers

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.

Image curtesy of i-astm.com

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!

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 sfwater.org/calaverasroad 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: Onunez@sfwater.org or Blauppe@sfwater.org.

See you around the valley!

Happy Thanksgiving!

Wild turkeys at the entrance of Calaveras Road

Happy Thanksgiving! For this special edition of our blog, I asked a few of my colleagues what they’re thankful for as it relates to their work at Calaveras Dam.

Here’s what they said:

I’m thankful for kind and caring coworkers. I’m thankful for good relationships between the contractor and the City. The whole team makes coming to work easy. –JT Munchin-Mates, Environmental Compliance Manger

I am thankful for the opportunity to with an awesome team. –Ritu G. Giri, Senior Engineer-Piping & Pipeline

I’m thankful for the different people I get to collaborate with. We all have different stories and it’s great that we can share and be a team. –Minh Nguyen, QA Inspector

I’m thankful for the memorable quotes that keep our meetings interesting and lighthearted. (1) ‘Where’s the topsoil?’ ‘We moved it.’ (2) ‘This is 5I? What have you done to it?’ (3) ‘It’s pooching out.’ (4) ‘This road is seldom used and moss has grown over it.’ (5) ‘There’s rock in the creek. I’ve seen it.’ (6) ‘C’mon man! You’re losing the focus.’” –Tedman Lee, Civil Engineer

I am thankful to work with intelligent, energetic, and supportive people that are dedicated to the work that they do. It’s also an added bonus to work in an environment where my colleagues make me smile and laugh. –Olivia Nunez, Communications Liaison

I am thankful for the many friends I’ve made during my time here and how we take care of each other and help each other out in our times of need. ☺—Wendie Busbie, Office Manager

As an engineering geologist, I am thankful for the opportunity to work on a major infrastructure project in such an interesting geologic setting, from the beginning of the design phase site investigations through construction. –Phil Respess, Senior Project Engineering Geologist

I am thankful that the Construction Management Team and the Joint Venture are communicative. Whether in the field or back at the office, maintaining an open line of communication is critical for both safety and efficiency and when an issues arises, the solution becomes a productive dialogue rather than a reproachful lecture. –Bill Stagnaro, Environmental Inspector

I am thankful for a great job and a supportive boss. – Jason Lau, FCA Assistant

I am thankful for the opportunity to be involved with the CDRP project. It is a special and challenging project that is highly educational and memorable. I am also thankful to be working with the project team. The staff from both the JV and CM Team are very competent, professional, and a pleasure to work with. –James Sakai, Project Engineer

This year, I am very grateful to be able to work with all of you in the Sunol Valley.  All your commitment, dedication, talent and hardwork have helped to make very good progress on all the Sunol Projects.  I am so thankful for all your contributions.  Wish you all have a Happy Thanksgiving with families and friends!–Susan Hou, East Bay Regional Project Manager

See you around the valley!

External Instrumentation at Calaveras Dam

Typical survey monument

The old and replacement Calaveras Dams are located approximately 1,500 feet from the Calaveras Fault.  This means that we need to make sure that there are devices in place to monitor the movements of both the current and future dams and the area around them. 

The future Calaveras Dam will have a total of seven types of instruments inside it and around it.  Today I will focus only on two types of external instruments that will be placed at Calaveras Dam to help us monitor and protect it -- survey monument and accelerographs.

 I will explain the purpose of each and the role each device plays at Calaveras Dam. 

Survey Monuments

Survey monuments are placed both around the exterior of a dam and later will be placed on the surface of the dam.  They are monitored periodically to determine if they have moved from previous measurements, which would indicate any significant movement of the ground surface has occurred. Survey monuments also track the change in elevation of the ground surface, allowing us to determine the settlement of the new dam embankment. Some of the survey monuments placed at Calaveras Dam have survey prisms permitting the monitoring to be done remotely using a digital theodolite (aka total station).   We will have a total of 65 survey monuments at Calaveras Dam.  

 Survey Monument with Optical prism

Accelerographs

Accelerographs are used to detect strong acceleration of the ground due to seismic forces. Accelerographs record the acceleration of the ground with respect to time. An Accelerograph is different than a seismograph. The difference is that an accelerograph doesn’t start working until something moves it.  A seismograph is recording continuously.  An accelerograph is a recorder that uses an accelerometer. Accelerometers are much less sensitive than seismometers, but have a much greater range. There will be 4 accelerographs installed around the new Calaveras Dam. 

These features are just some of the ways in which we are ensuring that the new Calaveras Dam serves our current and future generations of customers.

See you around the Valley!

Creepy Tarantulas and Tarantula Hawks

This week’s blog is about one of Sunol’s creepy crawlers—the tarantula. It lurks in the dark and doesn’t come out until October. It’s furry and looks menacing, but is it?

In Sunol there are two types of tarantulas: the blond and the brown tarantula. Pictured below is a brown tarantula or Aphonopelma smithi. This fellow was spotted by our field engineer, Ryan Dougherty.




If you’ve noticed an increase in spotting them, you’re not alone. In fact, it’s mating season for these giant arachnids. Male tarantulas will spend a lot of time weaving webs just above ground, outside the female’s burrow. If you don’t have a keen and trained eye, it is very difficult to tell the difference between a male and female tarantula. A typical tarantula reaches maturity at around 10 years. Most males die within a year after mating and females can live up to 25 years.

If provoked, the tarantula may inflict a painful bite, about like a bee sting. However, tarantulas tend to have a gentle nature, and rarely uses it’s fangs except to catch prey. If proved, it may raise its front legs and its abdomen to look aggressive. It may also release stinging hairs from its abdomen. These hairs irritate the skin of an attacker by digging themselves in with hundreds of tiny hooks.

They eat a variety of insects and other invertebrates, and their diet sometimes includes lizards, snakes and small rodents. They bite their prey, injecting it with digestive juices. Then they mash it with their strong jaws, and drink the liquid.

The tarantula’s feeding habits are gruesome but it's predator, the tarantula hawk, takes the word “gruesome” to another level. The tarantula hawk is a huge spider wasp. When the female tarantula hawk is ready to lay her eggs, she leaves the flowers behind and goes on the hunt for a tarantula. Once she finds one, she paralyzes it with a sting. Even though the tarantula is several times her own weight, she drags it to a hole, lays her eggs on it, and buries it. The eggs soon hatch into wasp larvae which slowly devour the paralyzed tarantula alive, from the inside out. Below is a picture of a tarantula hawk. Don’t let their beauty deceive you.



Image courtesy of San Antonio Express-News

If you are hiking in or around Sunol be on the lookout for these furry arachnids. Though they have fangs and carry poison, tarantulas are not considered a serious threat to humans. Please try not to step or run over one.

Happy Halloween!

New Fish Screens at Fish Passage

Last week several members of our Fish Passage project took a trip to Sacramento to examine the project’s fish screens designed by Intake Screen Inc. (ISI). Next week, our team will be installing four of these fish screens at Fish Passage Facilities located in Alameda Creek.

Pictured below is one of the four new fish screens.



Here is Yen Ng, one of our project engineer’s; looking through what is called an internal cylinder brush. The internal cylinder brush is a key component of the fish screen.



Below is a diagram of a fish screen and its significant components.


Image courtesy of http://intakescreensinc.com/

The goal of the Fish Passage Project is to provide for safe passage of fish around the Alameda Creek Diversion Dam to support the restoration of Steelhead trout to the Alameda Creek Watershed. The project is part of the San Francisco Public Utilities Commission’s $4.8 billion Water System Improvement Project (WSIP) to repair, and seismically upgrade portion of the Hetch Hetchy Regional Water System.

Construction is expected to be completed in fall 2018.

See you around the valley!