Monday, November 28, 2011

Sunol Region Holiday Open House

Drop into the SFPUC’s Sunol Region Holiday Open House for a celebration of the holiday season and the coming New Year! Come meet representatives from all of our projects in Sunol Valley. They look forward to chatting with you about all the work we are doing.

Light refreshments and activities for kids will be provided.

Thursday December 1, 2011
6:00 p.m. to 8:00 p.m.
Sunol Event Center
11684 Main Street

Monday, November 21, 2011

Ready for Rains

It’s been wet out there, lately. As the Calaveras Dam Replacement Project begins construction, the team is ready for winter rains. The contractors must be prepared to treat storm water runoff to protect the local creeks. Large areas of exposed ground created as part of construction have the potential to erode soils and impact the water quality downstream. The project has installed a treatment system to protect the local creeks. The treatment consists of removing any silts and clays that may be eroded from exposed excavation surfaces. The contractor has installed an active treatment system that consists of retention ponds and sand filters to clean turbid waters prior to discharging back to the Calaveras Reservoir. The treatment system is designed to manage a flow up to 2,400 gallons per minute, equivalent to approximately 57 bath tubs filled with water.


The treatment system is prepared to operate around-the-clock for the duration of the four year project. We currently anticipate treating approximately 270 million gallons water. As the project prepares to move over 7 million cubic yards of earth over the next four years, the treatment system and other erosion control features will help maintain the water quality in the Alameda Watershed.


For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Tuesday, November 15, 2011

New Irvington Tunnel: A Year in Construction

The New Irvington Tunnel Project celebrated its first year of construction this past September. When complete the new tunnel will provide a seismically-designed connection between water supplies from the Sierra Nevada Mountains and the Alameda Watershed to Bay Area water distribution systems. Take a look at the important work taking place above and below ground:



Year One by Numbers:

1 Tunnel Shaft: At 115-feet deep and 41-feet diameter, the Vargas Shaft is the starting point for two of the tunnel headings.

2 Tunnel Portals: Carved into hillsides between Sunol and Fremont the Alameda West and Irvington Portals are access and exit points for the new tunnel.

3 Road Headers: Weighing in at a combined 127 tons these mechanical tunneling machines are grinding their way through 3.5 miles of rock.

76 Secant Piles: Drilled and poured 115-feet into the ground this interlocking circle of piles form the support for the Vargas Shaft.

3057 Feet to Date: Miners have excavated this total from 4 tunnel headings.

Thursday, November 10, 2011

Welcome to our Headquarters


Frequent cyclists and commuters along Calaveras Road may notice new office trailers, nestled in the hills, approximately 7 miles from Highway Interstate 680. This is the official new home to the Calaveras Dam Replacement Project Team. The team has been working at the site months before the official trailers were completed in early November. Over 40 employees work daily out of the Calaveras trailers.

About the Team
Dragados USA, Inc./ Flatiron West, Inc./Sukut Construction, Inc. Joint Venture, combines international experience building dams around the world. Black and Veatch serves as the construction management firm for the project. Together with the SFPUC, the firms integrate a team committed to the sustainable development of California’s water projects.

As the largest project in the Water System Improvement Program, the Calaveras Dam Replacement Project team will replace the existing dam with a 220-feet high new seismically-designed, earth and rock-fill dam directly adjacent to the existing structure, restoring the reservoir to its historic water storage levels. All construction activities are expected to be complete in late 2015, and the project will reach final completion in 2016.

For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Wednesday, November 2, 2011

Four Steps to Protecting Water

A hydrogeologist collects groundwater data

In the hills between Sunol Valley and Fremont, the water that flows between the cracks and faults underground is worth more than gold. For nearly every property owner, it is their only source of water for drinking, agriculture and fire protection. It goes without saying that residents are very protective of their only water supply.

In the late 1920s, the construction of the existing Irvington Tunnel caused water levels in many wells, ponds and springs to drop. Fast forward to the present day and now you have an aging water system in serious need of a seismic upgrade. How did the New Irvington Tunnel project team come up with plan to protect water supplies? Here are the 4 steps:

1. Understand the problem“We understand the problem” said the project manager and engineers. Hydrogeologic experts were hired to study the groundwater table, and quantify and forecast the problem with a sophisticated groundwater model. Using the model the project team has identified which residents may be affected and developed measures to offset any possible water supply interruption for each resident. "We are concerned about the loss of groundwater too!”

2. Share your knowledge “Tunneling techniques have greatly improved over the past 80 years” said mining engineers and tunnel designers. Our team of experts described to the public how probe drills bore ahead of tunnel excavation to find pockets of water. If water is found, these holes are filled with grout keep the water from flowing into the tunnel.

3. Come up with a plan“What if I still lose water?” asked many property owners. A groundwater management program was developed by the project team. In addition to water monitoring, each property owner received a site specific plan detailing the steps the project team will take to prevent an interruption in water supply.

4. Keep your commitments – No matter how well the first three steps were received this last step is what people will remember. Did we do what we said we were going to do? The jury is still out, however, since we started the program hydrogeologists have monitored water levels and shared the information with property owners. Regardless of the time of day or day of the week the project team responds when a property owner thinks there is an issue with their water supply. This week, construction crews are installing measures designed to prevent an interruption in water supply.

The project team’s work is far from complete, however, the groundwork has be laid to protect local water supplies. As tunneling progresses, groundwater monitoring will intensify and the team will continue to be ready to respond.

Tuesday, November 1, 2011

Tarantula Crossing

Fall is tarantula time at the Calaveras Dam project site. The annual ‘tarantula migration’, which, begins in September through end of fall, is underway. Normally shy, living underground in burrows, and nocturnal, these hairy spiders are making their yearly journey above ground. The male tarantulas are migrating across our lands in search of female tarantulas to breed, and then the males scurry home in fear of being eaten by their new female companions. As part of our continuing efforts to protect wildlife, you will see many of our workers driving slow enough to stop and let the hairy critters cross the road, evident in this photo taken by our staff.

These hairy, eight-legged creatures have been feared by many. In reality, tarantulas have never caused any human deaths and are only dangerous to small insects. Tarantulas have very small venom glands and the bite of our tarantula is compared to a bee sting. Harmful spider bites generally come from poisonous spiders of other species. Although we wouldn’t want to find them inside the office trailers, we’re glad to yield to them on the roads outside.


For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Photo courtesy of Bill Stagnaro, Environmental Inspector & Biologist