Calaveras Dam Project Continues to Dig Away

Today the Calaveras Dam workers celebrated yet another milestone since construction began in August 2011.  Over 3 million cubic yards of soils and rock have been excavated to make room for the replacement dam.  The team enjoyed lunch on top of one of the disposal sites, where they have moved and compacted nearly 20% of the 3 million cubic yards of materials. 

Imagine the weight of 96 fully loaded Titanic ships--- this is the approximate equivalent weight of the 3 million cubic yards of soils and rock that have been excavated and moved to disposal sites around the project. 

By the end of the project, the Calaveras Dam Replacement Project will have moved more than 9 million cubic yards of soils and rock.  About 3.5 million cubic yards of the materials will be used in the construction of the new dam, while the remainder will be disposed of onsite.  As we celebrate today, we still have a lot of heavy moving to look forward to!

Calaveras Dam workers are acknowledged by Earthwork Superintendent Sam Aiello for moving over 3 Million Cubic Yards

View of the Calaveras Dam foundation today
where major excavation has taken place to make room
for the future replacement dam

Series #2 Do you Know Your Tap Water? – Local Waters

Second in our series of ‘Do you know your tap water’, begs the question, OK, 85% from Hetch Hetchy, straight through the Sunol Valley to our customers… but what about the rest?

 
The rest of the water supply comes from local reservoirs. In the Sunol Valley that includes two: Calaveras and San Antonio Reservoirs. Calaveras, when full, is our system’s second largest drinking water reservoir, second only to Hetch Hetchy Reservoir. It also stores only local watershed waters from the Arroyo Hondo and Alameda Creek. San Antonio Reservoir, on the other hand, stores water from San Antonio Creek, and we can also store Hetch Hetchy water there as well.
 

Calaveras Reservoir, shown here prior to the start of construction of the Replacement Calaveras Dam, stores local water only.

 San Antonio Reservoir Stores both Local Watershed Waters and Hetch Hetch Hetchy Water

We must filter the water from these local reservoirs at our Sunol Valley Water Treatment Plant before we send it to our customers.

Some facts about local dams and reservoirs that you may not know:

• The dam at San Antonio Reservoir is called Turner Dam, after former SFPUC General Manager, James H. Turner.

Turner Dam

• When originally constructed in 1925, Calaveras Dam was the largest earth-fill dam in the world.

Existing Calaveras Dam. The New dam is being constructed directly downstream of the existing one. The site looks very different today!

 

• Both reservoirs support habitat for many rare and endangered species. Each reservoir also has a nesting pair of bald eagles. Learn more about them here.

Catch up on the Do you know your Tap Water series.

See you around Sunol Valley!



Join Us at the Summer Open House!

Summer Open House at the Sunol Water Temple

We would love to show you our progress on projects in and around the Sunol Valley, including water system upgrades, watershed environmental improvements, plans for the fire system upgrades and the latest plans for the Watershed Center to name a few. We hope to see you there!

When: Wednesday, June 26, 2013, 4:30 p.m. to 6:30 p.m.
Where: Sunol Water Temple (505 Paloma Way Sunol, CA 94586)
What: Enjoy light refreshments, see photos and updates of ongoing SFPUC work in the Sunol Valley and talk with team members
Info: For more information, please call (866) 973-1476 or email epowell@sfwater.org.

Our Resident Bald Eagles

The land that we own in the Southern Alameda Creek Watershed has been protected for over a century.  By controlling the activities on our watershed lands, we ensure top water quality for our customers and preserve prime habitat for rare and endangered species. The 36,000 acres the SFPUC owns have become an oasis.

These lands are home to all sorts of plants, insects, and critters, including the Most Beautiful Jewel Flower, Callippe Silverspot Butterfly, California Tiger Salamander, California Red-Legged Frog, Alameda Whipsnake, Golden Eagles, and not one, but two nesting pairs of Bald Eagles.

Interestingly, both eagle pairs nest not far from our ongoing construction projects at Calaveras Dam and at the habitat restoration project at San Antonio Reservoir.

Our environmental teams monitor the eagles’ success annually and establish a wide “No Disturbance” boundary around the eagle nests, in coordination with the US Fish and Wildlife Service and California Department of Fish and Wildlife, to avoid aggravating nesting bald eagles. During nesting season, teams closely monitor the eagles’ activity around both reservoirs to ensure our construction work does not affect nesting birds. We go to great lengths to ensure that these special animals continue to thrive.

 

We are proud to announce that the eaglets (two at Calaveras and two at San Antonio) of both eagle pairs are very close to fledging!  The young eagles will continue to receive care from the parents for a while before exploring new territories on their own.  The parents – soon to be “empty nesters”  – will likely stay in the neighborhood to take advantage of the plentiful food source and relative isolation and protection the southern Alameda Creek watershed provides.

Calaveras Reservoir Bald Eagles
Photo permission courtesy of Tam Phan

Calaveras Reservoir Eaglet takes flight
Photo courtesy of Bill Stagnaro, Environmental Inspector

Environmental Compliance Manager Cullen Wilkerson and Specialty Environmental  Monitor Aaron Sunshine survey our Bald Eagles

Calaveras Reservoir Eaglet soars through Sunol Valley
Photo courtesy of Bill Stagnaro, Environmental Inspector

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

What on Earth is That?

Anyone notice the arrival of a large, red machine at the San Antonio Backup Pipeline work site this week along Calaveras road (south of I-680)? 

It is actually an excavator with a 100-foot long digging arm. Why, you might ask, would we need a 100-foot long digging arm to build a pipeline?

Good question! It will be used by one of the subcontractors on this project, Magnus Pacific/Inquip, a Joint Venture, to construct the cement slurry wall around an unused quarry pit in the Valley. When the project is complete, the pit will temporarily store occasional discharges from the Hetch Hetchy Regional Water System. To that end, we need to construct a deep cutoff wall to prevent groundwater from seeping into the pit in the future.

The large excavator will dig a deep trench while the contractor fills the trench with cement slurry. The slurry will keep the trench from collapsing, and it will harden over time to create the barrier that will keep groundwater out. The trench is deep, the ground is wet, and the work is difficult - perfect for the new machine out there.

Once complete in 2015, the San Antonio Backup Pipeline will add operational flexibility to the water system that currently serves 2.6 million customers.

See you around the Sunol Valley!

Do you know your Tap Water? Series #1

It’s likely that few of our 2.6 million Bay Area customers think about how we make sure that high quality water reaches their taps each day. We’d like to change that…. In a series we’re calling, ‘Do you Know Your Tap Water’?

#1 Hetch Hetchy

 

More than 85% of the water we provide to you, our customers, comes from Hetch Hetchy Reservoir. It has to travel the width of the State of California in order to reach your taps. Here are a few facts about the system that serves you that you may not know.

 

  Hetch Hetchy Reservoir

 The Hetch Hetchy Regional Water System was constructed in the 1920’s and 1930’s.

The Mitchell Shaft Crew pauses for a photo in 1934.

• As water tumbles out of the Sierra Nevada Mountains, it generates hydropower to power services in the City of San Francisco, such as S.F. International Airport, MUNI and City Buildings. 

• Water moving downhill rotates 8 individual  turbines to generate hydropwer, such as the one pictured here in 1927.

This water travels all the way to the Bay Area using only the power of gravity.

The source of this water is so outstanding – melted glaciers sitting on a granite basin – that we that we do not have to filter water from Hetch Hetchy Reservoir.

Did you know that the SFPUC worked out of a Livermore office during construction of the Hetch Hetchy Regional Water System?

 

Calaveras Dam Completes Major Work on New Intake Structure

Our contractor recently completed the final concrete pour for the new intake structure, which is a key component of the Calaveras Dam Replacement Project.  This tower is the connection point for the water pipelines that draw water from the reservoir, before it is treated at the Sunol Valley Water Treatment Plant and then sent on to our 2.6 million customers.

The contractor used 1,400 yards of concrete to build the new intake structure.  That is the equivalent to the weight of more than 12 cable cars!  At 214 feet tall, the structure is almost as tall as the height of the new Calaveras Dam (220-feet-tall). It took our crews more than 29,000 hours to construct the tower.

Crews still need to finish the exterior work on the structure, which will replicate the architectural style of the original tower that was built in 1925. The final external touches are expected to be finished in a few years’ time. 

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

Original Intake Structure built in 1925

New Intake Structure in progress today

The Calaveras Dam team gathered to celebrate this milestone at the site