Photo Friday at the Bay Division Pipelines

Happy Photo Friday!

We've been neglecting the Bay Division Pipelines in our East Bay Photo Series. So we thought we'd celebrate this Photo Friday with a couple of construction shots - from 1966.

Five Bay Division Pipelines transmit Hetch Hetchy and East Bay supplies through our two Irvington Tunnels to our 2.7 million Bay Area Customers.  Bay Division Pipelines 1,2, and the newest addition - 5 connect to a brand new water tunnel under San Francisco Bay on their way to the Peninsula.

Pipelines 3 and 4 pass through the South Bay overland on their way to the Peninsula. 

As you can tell, these are large pipelines. They are also crucial to our water transmission system.

We can't blame those kids. We think they're pretty cool, too!

See you around the Valley!

Another Shut Down for the Books

The New Irvington Tunnel Project has just completed its winter pipeline shutdown work this season.

“What’s the big deal?” you ask. Here’s why.

Our construction team must construct upgrades to this water system while it still provides water to our 2.6 million customers.  We shut down the pipelines in order to cut into them and weld pipeline connections to improve your water system.  We can only do this for short periods of time during winter months when demand for water is low. The timelines within which the contractor can complete their work are very short. The work is very complex and challenging in a very tight area. No pressure!

At the Irvington Portal area in Fremont, the contractor Southland Tutor Perini had two shutdown seasons – last year and this – to complete a complex set of pipeline connections between the existing Irvington Tunnel, the New Irvington Tunnel currently under construction, and the five Bay Division Pipelines. These pipelines can only be shut down one at a time during winter months.

The SFPUC is creating pipeline connections to allow water to be distributed from both tunnels to all five pipelines in a variety of ways.  Work on the final Bay Division Pipeline #4 connection started on November 5, 2012, and the project team recently completed the work.

For our customers this means a water transmission system that will be more flexible from an operational standpoint and better able to withstand a major earthquake.  For our construction team it means a pat on the back for a job well done.

Work being done on the final Bay Division Pipeline #4 Connection

Workers perform welding work on pipeline

For more project info, please email mle@sfwater.org or call our 24 hour answer line at 866-973-1476.

Seashells and Secant Piles

A recent trip to the Sunol Valley by SFPUC photographer Katherine DuTiel produced a photo that, by striking coincidence, looks remarkably like one taken on the Bay Division Pipeline Project on the Peninsula.

Look closely to see which is which!





Shown here is the receiving shaft of the Bay Division Pipeline micro tunnel section on the Peninsula. The project was forced to tunnel under a culturally and environmentally sensitive area at the end of this 9 mile pipeline. The secant wall in the shaft consists of a series of drilled piers filled with concrete. They are arranged concentrically to provide a continuous concrete wall that supports the shaft.



The Sunol Valley area was covered by the Pacific Ocean about 20 million years ago. Life along the old coast was similar to today, with abundant clams, mussels, sea worms and other invertebrate organisms living in the sand. The sandstone formation that represents the old ocean deposits is called the Temblor sandstone, and contains fossils from this old coastline. The photograph shown above is a fossil scallop collected by geologists at the Calaveras Dam Replacement Project.

NIT: A Photo Update

As construction of the New Irvington Tunnel moves forward, here is a quick peek into some of the work taking place to provide a seismically safe water connection 2.6 million people. Photographs by Katherine Du Tiel and Robin Scheswohl © San Francisco Public Utilities Commission.

Workers install 96-inch sections that connect the
New Irvington Tunnel to the Bay Division Pipelines.

Old sections of the Bay Division Pipeline must be torn out to make way for new sections.

A worker welds sections of the new pipeline together.

Modifications are made to the tunnel’s rail and muck system. Materials and workers travel into the tunnel, and soils and equipment come out of the tunnel on a series of special rail cars.

The men and women of the New Irvington Tunnel: Working hard to ensure safety of the water supply for 2.6 million people.

Airplane in Flight

Rebuilding our water system has often been compared to repairing an airplane in flight. With 2.5 million people relying on safe, high quality water- the Hetch Hetchy Regional Water System must continue to operate even as it is systemically upgraded to meet seismic standards. The work currently taking place at the New Irvington Tunnel Project is an excellent example of the balancing act that takes place.



The major water transmission pipelines that connect into the New Irvington Tunnel can only be taken out of service individually, and for short periods of time in winter, when demand is typically low. This allows for other waterlines to continue to operate while individual ones are under construction. This also means the construction team only has a limited window of time to complete their work before waterlines must come back into service.



This winter workers have the challenge of replacing three waterlines between October 2011 and May 2012. Each line must be completely drained before workers can demolish and remove the 70 year old concrete and steel pipes. Workers then install new welded steel pipe connections as large as 102” in diameter. The waterlines are then buried until the new tunnel can be connected to them. A fourth waterline will be taken out of service next winter when water demand is again low.



Crews are working hard and are on track to meet the tight schedule this year As we move forward with the New Irvington Tunnel’s critical seismic safety upgrades, we will continue to provide the same high quality water to our customers at the same time.