A Family Connection to the Old Calaveras Dam

We at the Calaveras Dam Replacement Project were extremely honored to host a very special guest, Geneva Barrett (Hunt). She was accompanied by her daughter, Debbie and her son-in-law, Randy  of Dublin, California.

Geneva has a special connection to the old Calaveras Dam. Her father, Frank Hunt, worked on the second Calaveras Dam (the first dam slumped under its own weight in 1918). The second Calaveras Dam was built between 1918 and 1925. Frank Hunt was a civil engineer on the project and operated a drag line.  Geneva was born in Sunol in 1927.


Randy and Debbie with Geneva Barrett (Hunt) on far right.




The late Frank Hunt circa 1920's.

After the dam's completion, her father relocated the family to Oregon where he continued to work on dams in and around the the state. Geneva recalls her dad as being very dedicated to his profession and to his family. During those times, her father worked all week at his designated job site and came home during the weekends only. She was one of twelve kids.



Frank and Maude Hunt with their first four children in Sunol.


Geneva told us that seeing the old dam was on her bucket list. We were so pleased to meet her and her family.

See you around the Valley!

Women's History Month With Iesha Morris

March is National Women’s History month. In honor of the contribution of hard-working women everywhere, we want to highlight our field laborer, Ieisha Morris. Ieisha has been an integral part of the Calaveras Dam Replacement Project Team for over 3 years.  You can’t miss her at the site.  She’s always on the job site with her Kawasaki mule.

The Calaveras Dam Replacement Project is her first construction job. She came to the project through the Cypress Mandela Training Center.  The Cypress Mandela Training Center is a community based organization that provides pre-apprentice construction and life skills programs. The SFPUC’s Office of Labor Relations works together with the Mandela Cypress Center to help place graduating students of the program at construction jobs. 

Ieisha starts her day early in the morning. She does everything from cleaning up equipment and  managing the garbage and recycling to keeping the onsite water treatment system working and escorting trucks to the job site. In other words, she does just about everything to keep the busy project moving.    

She says the she really enjoys working outdoors. “I learn something new every day on the job site and it has been fascinating to see the dam go from plans on paper to an actual tangible project.”



Ieisha hopes to continue to work in the construction industry after her job is complete at the Calaveras Dam Replacement Project.  When she is not busy working, she likes to hike and spend  quality time with her two sons and her extended family.

On behalf of the Calaveras Team we want to thank Iesha and all the field laborers for all of their incredible work to make the Calaveras Dam Replacement Project a success.

For more information on the Cypress Mandela Training Program: http://cypressmandela.org/

See you around the Valley!

Photo Friday: Calaveras Reservoir

Mother Nature has given the Bay Area a serious drenching during the last couple of weeks.

So much in fact that Calaveras Reservoir has started to fill. The SFPUC lowered the water level in Calaveras Reservoir because of seismic concerns about the old Calaveras Dam.

The SFPUC built a new dam, which reached its full height in September. This means we are ready to allow the reservoir to start filling with local Alameda Creek Watershed runoff.

And fill it did.


This photo was taken in January 2019. The remnants of the old dam are seen on the right, where the reservoir begins to fill. The new dam is on the left.



This photo was taken last week. The reservoir has filled the entire space between the old and new dams.

Calaveras Reservoir helps supply drinking water to 2.7 million residents in four Bay Area counties.

The Calaveras Dam Replacement Project is 98 percent and is scheduled to be completed in spring 2019.

See you around the Valley!

Happy Holidays from the SFPUC

We hope you are having a joyful and restful holiday season!

It doesn't snow very often in the Alameda Watershed, so we had to go way back into the photo archives to find this one from the Calaveras Dam construction site, dated January 9, 1913. The site was so remote at the time that onsite camps housed construction workers.

Calaveras Dam was constructed three times in total. 

• The first dam, started in 1913 and completed in 1918 collapsed under its own weight because of the dam construction method builders used.
• The second dam, which served us for over 90 years, was completed in 1925. 
• The third replacement Calaveras Dam reached its full height in September 2018.

Happy Holidays to you and yours!

See you around the Valley!

Spraying it Green

Most of us don’t give hydroseeding much thought. As it turns out, we at the Calaveras Dam Replacement Project do.

Hydroseeding is, in essence, spreading seeds over an area after the ground has been disturbed by things like the construction of a large dam.  It is an important part of restoration and erosion control.  What is cool is the way we plant these seeds.  What we call hydroseeding was invented in the 1950's and involves mixing mulch, seed, and water together to form a slurry and then literally spraying it on the ground. This mixture increases the likelihood of germination of the plants and it holds firm to sloped areas.

One of the best times to hydroseed is the fall, which is why our teams are spending a lot of time hydroseeding now.  Our hydroseed is a mix of native annual and perennial grasses and forbs that grow quickly and easily from seed. The restoration goals for the project include establishing native plant communities. The vegetation provides habitat for threatened species and helps improve water quality.

Here is a beautiful picture of the recent hydroseeding of Borrow Area B (BAB). The green color is not green grass but a natural dye used so the contractor can track locations where they applied the hydroseed. The color will eventually disappear until the vegetation begins to grow. 






And, here is a picture of the newly hyroseeded dam. You can see the hydroseeder (truck) spraying the hydroseed onto the dam's face.  The thick lines are straw wattles used to prevent erosion on the slope.

Here is a closer picture of one of our workers spraying the hydroseed onto a steep slope.

Now we just need a nice winter's rain to help the hydroseed grow. 

See you around the Valley!

Love Your Local Stilling Basin

We have written a great deal about the spillway at the Calaveras Dam Replacement Project. Completed in 2016, this spillway is the width of a six lane freeway, and the height of a three-story building. The spillway's job is to protect Calaveras Dam by allowing water from Calaveras Reservoir to flow safely around, and away from, the dam in extreme high water events.

We have neglected to highlight an important component of a spillway - the stilling basin. Today, we'd like to generate a little love for stilling basins.  

A stilling basin is a structure that dissipates the energy of the water rushing down the spillway. Without a stilling basin, water coming out of the spillway could scour out the foundation of the dam, the base of the spillway, and nearby creek beds. In short, the stilling basin is a sort of bodyguard for the dam.

Stilling basins come in a variety of types, but generally fall into two categories: a straight drop for lower elevations, or an inclined chute. The stilling basin at the new Calaveras Dam is an example of the latter category. To be specific, it is a United States Bureau of Reclamation (USBR) Type II stilling basin.  Our stilling basin is approximately 200 feet long, 45 feet high and 80 feet wide.    

Water flowing down the new spillway of the new Calaveras Dam will drop 200 feet in elevation before it reaches the stilling basin at the bottom.The stilling basin creates a hydraulic jump to slow down the high velocity water before it slowly, and safely, discharges into Calaveras Creek.

A view of the new stilling basin at the Calaveras Dam Replacement Project

So, let's hear it for the humble stilling basin!

See you around the Valley! 

Meet Glen Gorski, Lead Quality Assurance Inspector

As the Calaveras Dam Replacement Project starts to wind down, we'd like to focus on some of the key people that have played a crucial role in the construction of the replacement Dam. 

This week we'd like to introduce you to Glen Gorski. He is the Lead Quality Assurance Inspector for the project. A big part of his job is to ensure that the project is being built correctly. 

He and his team are tasked with observing and reporting that quality control measures are effective, so that the entire dam project is being constructed to the expectation of the San Francisco Public Utilities Commission.  He is a wealth of information and insight and he knows every detail of the dam's construction. If you have a question, Glen will always have the correct answer.
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Here is Glen with his team.

Glen has over 40 years of experience in the construction industry. He has quite a resume with two Bachelor of Science degrees in Engineering and Geology from the University of Notre Dame and one Masters of Science in Civil Engineering from Notre Dame and a Masters of Science in Business Administration from the University of Indiana. He started his career as a geotechnical engineer for the Scilts Graves & Associates. 

He says that the biggest lesson learned in his career is the importance of "paying attention to the contract." Paying attention to the contract will save you plenty of headaches in the long run. Out of the plethora of projects he's worked on throughout his career he says that the most interesting one is his work at Snoqualmie Falls where he was refurbishing a hydro electric power plant built in 1895.

When he is not working at the Calaveras Dam Replacement Project, you can find him volunteering at his local Community Emergency Response Team (CERT) group, golfing, leading a Boy Scout troop, or spending time with his grandchildren.



Glen enjoying the great outdoors.

The team at the Calaveras Dam Replacement Project would like to thank Glen for his commitment to excellence. 

See you around the valley!

Photo Friday - Calaveras

Happy Photo Friday

Here are a couple of shots from the Calaveras Dam Replacement Project taken this week.

The dam itself is growing higher and higher on the lower left. A portion of the existing dam is shrinking lower and lower on the center right as crews excavate the approach channels. 

On the new dam itself, crews use large equipment to transport and compact the materials for the earth and rock fill dam, as well do hand work, such as vacuuming the foundation of clay core of the new dam. Why vacuum? To ensure a solid connection between the core and the bedrock and protect the integrity of the new dam.


Have a great weekend, everyone! And see you around the Valley!

What's the Big Deal about an Approach Channel?

We are building a new earth and rock fill Calaveras Dam right next to the existing 93 year-old dam (directly downstream of the existing dam as they say in the dam industry.)  As many of our previous blog posts have been tracking, we have been busy building the new dam, foot by foot, from the bottom up like a layer cake. A very large layer cake.

Our Calaveras cake is high enough now to allow us to begin to excavate out the approach channel to the new dam this week.

"What is an approach channel?" you ask. An approach channel is a breaching of an existing dam in order for its adjacent reservoir to come in contact with it. We will remove a portion of the existing dam (500,000 cubic yards of it to be exact) to allow reservoir water to eventually fill in the space between the old dam and the new dam. The old dam will look like a peninsula in the reservoir when the project is done. 

"Why not remove the old dam in its entirety?" We don't have to. Complete removal would be expensive, environmentally difficult, and not necessary to operate the reservoir. 

The start of excavation of the approach channel means that we have reached a high enough elevation with the new dam to safely begin carving out a huge chunk of the existing dam. It's a coming of age for the new dam, if you will. A significant milestone. 

Here is what the approach channel looked like at the beginning of last week.



And, here is what it looks like this week.




The channel will be lined with large rocks called rip rap to protect it from erosion so the channel will be ready when we start to refill the reservoir this fall.

Approach channels may not seem exciting at first glance, but we at the SFPUC are thrilled!

See you around the valley!

Fossils from the Calaveras Dam Replacement Project Find their New Home

The San Francisco Public Utilities Commission (SFPUC) has been working since 2011 to build a replacement Calaveras Dam out of seismic concerns for the existing 93-year-old dam in the Sunol Valley.

To make space for the new earth and rock-fill dam, the Calaveras Dam Replacement Project has had to move almost 10 million cubic yards of soil and rock. While moving all this earth, the project team began to find what has been called one of the greatest fossil finds in the Bay Area in decades.

To date more than 1,300 specimens have been discovered. Most them are fossils from an ancient ocean and beach area approximately 15 to 20 million years ago. Water covered much of California back then, and an inland ocean extended to the Central Valley.

Many of the fossils are high-quality specimens that can be used to further research into evolution or global change. (UC Berkeley photos by Sara Yogi)

Amongst the vertebrate fossils are marine mammals, like baleen whales or Mysticetes and toothed whales and dolphins or Odontocete; and Desmostylus, an herbivorous hippo-like marine mammal), seals or sea lions, sharks, and bony fish, such as halibut.  The invertebrates include scallops (some as big as a dinner plates), clams, snails, cockles, mussels, crabs, and barnacles. The team believes it has found a new species of whale among the dozens of whale skulls found.

Researchers have pieced together the jawbone from a 15- to 20 million-year-old whale. 

(UC Berkeley photos by Sara Yogi)

Researchers can tell this area was near to shore because they have also found plant material that washed into the ocean from land, including pine cones, palm trees, leaves, and wood. They can tell that the Bay Area was warmer back in this time, and the ocean teemed with life.

Through an agreement between SFPUC and the University of California Museum of Paleontology (UCMP) the entire collection of fossils will now be housed within the UCMP collections. The fossils represent California’s fossil heritage and as such, belong to all the citizens of California, and will be managed on their behalf by the University of California Museum of Paleontology. 

The UCMP assembled a team to manage this collection, including a Lab Manager – Dr. Cristina Robins, many undergraduate students, two graduate students per semester, and volunteers.

Graduate student Mackenzie Kirchner-Smith uses a brush to spread adhesive over a fossil found during the Calaveras Damn replacement project. (UC Berkeley photos by Sara Yogi)

Dr. Robins and her team painstakingly chip away the rock from the fossilized bone to identify each specimen. It is laborious work. They often find new specimens inside the rock blocks around other specimens. More fascinating fossil discoveries lay ahead for the UCMP team.

Fossils waiting to be released from rock fill the small lab located at UCMP.

And we at the SFPUC know the fossils are in excellent hands.

See the video and read more here:

See you around the Valley!

The Building Blocks of the Replacement Calaveras Dam

If you are new to the world of dam construction, you might wonder what types of materials are used in building one.  Today’s blog will focus on what types of materials we are using to construct the new Calaveras Dam. Calaveras Dam is an earth embankment dam.  Earth embankment dams tend to be constructed of all types of geologic materials.

Calaveras Dam, July 2017

The picture above was taken recently; from it you can visually see the different materials. Let’s start with the middle and the most important material used in our dam, the core. 

The Core of Calaveras Dam

Zone 1 & 1A—aka…the Core

The core is made up of clay.  Clay is very dense and less permeable than most materials.  Our new dam will have a large core, which will help ensure that the dam withstands a 7.2 magnitude earthquake.  The clay used in our dam has been ‘borrowed’ from the south end of Calaveras Reservoir.

The core is taking shape.

Zone 1A- Core’s foundation

At the bottom of the core, you will find Zone 1A material. This clay is plastic, pliable clay, or another words, clay that has a Play-dohtm like consistency.   Zone 1A material is placed on the foundation’s bedrock and acts as a seal against water flow beneath the dam.

The core is the most important element of the dam and therefore must be protected.  We protect our core by using filters in both the upstream (reservoir side) and the downstream (dry side) of the dam to control the seepage of water and remove it safely from the Dam.

Zone 2 and 2A- Sand

Upstream zones are made of sand  (Zone 2A) and large gravel (Zone 5A)The downstream filters or chimneys are made of sand (Zone 2) and pea gravel (Zone 3).

Zone 5-Rock Fill

Further protection for both the core and filters is provided by rockfill shells. The upstream shell consists of hard durable rock because it will be submerged in the reservoir, Zone 5 material.  This material consists of metamorphic rock known as blue schist.

The downstream shell (Zone 4) consists of onsite material from a geologic formation known as Temblor Sandstone.  While this is a sedimentary rock, it tends to degrade into a gravelly, sandy soil and is best suited for drier conditions than the upstream shell.

Zone 6- Rip Rap

Wave action in the reservoir due to wind can erode most earthen materials.  Large durable rocks are placed on the slopes of the dam at the waterline to prevent this erosion. This is Zone 6 also known as rip rap.

Image courtesy of www.fhwa.dot.gov

See you around the valley!

Building Dams in Earthquake Regions, Part II

As Californians, we live with the possibility of earthquakes.  Here at the Calaveras Dam Replacement Project we are in the middle of constructing a new dam that will be strengthened to resist seismic forces and withstand a 7.25 magnitude earthquake.  Dam technology has evolved since we built the original dam in 1925. 

If you missed our first blog about the technology used in construction of the original dam, see it here. The methods used in constructing the new Replacement Calaveras Dam are very different. Here’s why.

New Construction Methods

We are using state of the art dam technology and engineering to enhance the safety of this large civil structure.

A Sound Foundation

Our director Dan Wade says that building an earth and rock fill dam is a lot like painting a house. You need to strip all the old paint off the walls to get to good wood. You need to prime the surface so it will hold the new paint. The very last thing you do is paint.  We have been doing the preparation for the building of our dam for 6 years. We have moved more than 7 million cubic yards of soil to reach competent rock as a solid foundation of the new dam. 

A cross section of the replacement dam showing the different zones. Green is upstream (the reservoir side), light yellow is downstream, the clay core is in the center, and the narrow yellow strips are the drains and filters.

Controlling Water Seepage

We have drilled the grout curtains (see our previous blog about curtains and blankets) extending more than 100 feet below the dam’s foundation to control water seepage. We have done even more work to treat the foundation of the core of the dam, which is made of impervious clay. Remember the drain blanket? That also is constructed on the downstream face (the dry side away from the reservoir) to control water. The new dam will have various filter zones and drain zones on both sides of the dam to control the movement of water so it does not compromise the structural integrity of the dam.

Resisting Seismic Forces

A wide core will help the new dam be robust. In addition, the materials placed in this dam will be compacted using heavy machinery.

Here's the dam being constructed as it looks now. The different zones are clearly visible.

The complete removal of unstable rock and soil to form a solid foundation, careful design and placement of filters and drains within the dam to control water, extensive grouting and sealing of the foundation of the dam, a robust core and heavy compaction of all materials enable the replacement Calaveras Dam to withstand seismic forces and serve our customers for generations to come.

Monitor our progress at building the dam here at sfwater.org/sunolvalley.

See you around the Valley! 

Building Dams in Earthquake Regions Part I

The First Two Calaveras Dams

As Californians, we live with the possibility of earthquakes.  Here at the Calaveras Dam Replacement Project, we are constructing a new earth and rock-fill dam that will be strengthened to resist the seismic forces and withstand a 7.25 magnitude earthquake. 

Dam technology has evolved since we completed the original dam in 1925. In a two-part series, we’re going to take a look at how our predecessors built the previous Calaveras Dam, which has served us well for 90 years, and what new technologies and construction methods we are using for the new dam to be ready for the next big quake.

The original Calaveras Dam (construction spanned 1913 to 1918) was constructed using the so-called hydraulic fill method.  Basically, to create the impermeable 'puddle core', fine soils were washed off the surrounding slopes with high pressure water cannons, and this slurry was collected between two 'training' dikes on both sides of the dam’s core.

During gold mining in the Sierra foothills, this method was used to build much smaller dams to impound water for hydraulic mining. But scaling this method up to this size had some serious problems. 

The first Calaveras Dam, nearly complete in 1918. It was the largest earthen dam in the world at the time.

The process did not allow excess water in the puddle core to dissipate, and this extra weight exceeded the ability of the upstream shell to retain it, and it failed as it neared completion.

The second (current) dam was completed in 1925 and was built on the remains of the first dam. For the current dam, soil was compacted in the core, primarily by running heavily-loaded wagons over it (pulled by mules). In this photo you can see the mule trains compacting the core.

The second Calaveras Dam, shown in 1926.

However, one problem that wasn't addressed during the construction of the current dam was the fact that alluvial soils (creek sediments including silt, sand, and gravel) were not removed before the first dam was constructed. Such saturated, loose sediments, which are removed during the construction of a modern dam, have the potential to 'liquefy' as they are shaken during an earthquake. 

It was for this reason that we at the SFPUC elected to build a completely new dam next to the existing dam.  And this time, things were different. 

Stay tuned to learn more!

Blankets and Curtains for Calaveras Dam?

Here at the Calaveras Dam Replacement Project we are building what is called an earth and rock-fill dam. The replacement Calaveras Dam, like all so-called embankment dams, is made of mostly compacted earth (see a cross section of the future dam below). An important aspect of this type of dam is the management of water. All earthen dams leak, the important thing is to control where the water flows to protect the integrity of your dam.  In the case of the Calaveras Dam Replacement project, we accomplish this with blankets and curtains. 

No fooling! Here’s how it works.  For years, the crews onsite have been constructing an entire dam that extends more than 100 feet below the base of the future dam.  We call this a grout curtain. Grout for those of you not in the construction industry is a special mix of cement that can be injected or literally blown onto a surface to seal it.  

Grout Curtains

As you can see in the photo from 2015, crews drilled countless small diameter holes into the bedrock a hundred feet down below the future dam and injected the holes with pressurized grout. The grout effectively seals up cracks and fractures within the rock underneath the new dam.  We did this for years. Why is this grout curtain so important? It prevents water from seeping underneath the new dam and undermining it.  In essence we drilled an entire new dam underneath the future dam. 

Drainage Blanket

If you thought grout curtains alone were enough to protect the future Calaveras Dam, guess again! We need blankets, too. More specifically a drainage blanket. The drainage blanket prevents water from exiting to, and damaging, the down-stream face of the dam (the face of the dam away from the reservoir).  At the end of the drainage blanket we are constructing a ‘mini dam’ made out of the same clay material as the core to capture any water in the drainage blanket. You can see the drainage blanket being constructed here.  This ‘mini dam’ is also known as the seepage barrier.  This seepage water is then collected in an inspection well to monitor the condition of the dam.

The Calaveras Dam Replacement Project, along with its blankets and curtains, is more than 80% complete.

See you around the Valley!

Photo Friday at the Calaveras Dam Replacement Project

Did you ever look at a photo of yourself or a family member from a long time ago and compare it to a recent picture? For today’s Photo Friday, we decided to do just that for the Calaveras Dam and its replacement.

Calaveras Dam in 2011. The project groundbreaking was in 2011. 

Calaveras Dam in April 2017. The project is more than 80% complete. We have moved more than 8 million cubic yards of rock and soil to date. We have fully excavated and grouted the left and right abutments. And in the center of the picture, the core of the new Calaveras Dam begins to take shape.  The huge concrete spillway (as wide as a freeway) is visible at the lower right. Wow.

Construction on this project started in 2011 and is expected to be complete in April 2019.

To learn more about this project and see a time lapse video of all of this excavation, visit us here.  

See you around the Valley!

Celebrating Amazing Women Near You

Just this week, we celebrated International Women’s Day on March 8^th. March is also the beginning of National Women's History Month. In honor of the contributions of hard-working women everywhere, we wanted to highlight a few fabulous women who happen to work at the Calaveras Dam Replacement Project whose daily contributions ensure the success of this critical project. 

Eunice Lee, Field Engineer, Sukut Construction

As an alumna of the UC Irvine Civil Engineering program, Eunice has been working on heavy civil construction projects since 2010.  As part of the contractor’s team, Eunice is a field engineer who specifically oversees the installation of geotechnical instrumentation and the permanent power system for the future replacement dam.  Eunice truly enjoys being a part of this team working with so many experts and experienced individuals to build something great. 

Karene Salaam, Project Controls Analyst, Black and Veatch

Staff who make important contributions to the project don’t always work in the field. We have a team of people whose task it is to track project costs and spending. On a job the size of the Calaveras Dam Replacement Project, this is no simple task. Karene Salaam is part of the Construction Management team and oversees the preparation of cost reports, progress charts, manpower plans, equipment and material costs and project schedules.  Her careful review and analysis ensures the San Francisco Public Utilities Commission has close financial oversight of all project spending by the construction contractor and the subcontractors.

Carrie Dovzak, Geologist, Environmental and Naturally Occurring Asbestos Compliance Monitor, San Francisco Public Utilities Commission (SFPUC)

Carrie Dovzak has worked for the SFPUC for 10 years, the last 6 1/2 of it working on Sunol Valley projects. It is Carrie's job to monitor construction activities to ensure compliance with environmental regulations and protections. She studied geology after traveling the world with her family - a perk of her father working for Pan American Airlines. After graduating, she mapped landslides in Northern Italy before returning to the U.S. to join her family. She continued her studies in Engineering Geology and Environmental Education at San Jose State and Hayward State. "Everyone should take a few classes in geology, you see the world in a completely different way!" she insists.

Ritu Gyawali Giri, Senior Engineer, Piping and Pipeline, Sukut Construction

Ritu Gyawali Giri is part of the outlet works team. She and her team focus on the new piping and pipelines that allow the SFPUC to take water out of the reservoir to our customers. She began in the construction industry in 2002, as a Site Engineer in Nepal. She has worked on projects all over the world, from Asia to Africa to the United States. Ritu relishes working through the geographical and environmental challenges to build the new Calaveras Dam. She is delighted to be a woman engineer working at the Calaveras Dam Replacement Project.

A Day in the Life of a QA Inspector

Meet Minh

Minh Nguyen is one of our QA inspectors working at the Calaveras Dam Replacement Project. On a chilly morning in Sunol Valley, he is typically one of the first team members on-site with a coffee in hand.

What is a QA Inspector? A Quality Assurance (QA) inspector is someone that ensures the project is being built correctly. They are tasked with observing and reporting that quality control measures are effective, so that the entire dam project is being constructed to the expectation of the San Francisco Public Utilities Commission.

“Divide and conquer,” is the motto Minh likes to personally use every morning when the team of QA inspectors report to each of the major activities on site. The QA Inspectors pair themselves with a Quality Control (QC) inspector as they observe activities such as placing materials into the dam, cleaning and preparation of rock, installing rebar, and testing of materials used to build the dam will meet specific quality standards. Communication is of vital importance between the QA and QC because they all need to agree to the same level of quality. When Minh is not performing QA Inspection at Calaveras Dam, you can find him playing a game of flag football, rock climbing, backpacking in the wilderness, or just hanging out with friends on the weekends.

Minh working on inspection of the Stream Maintenance Building

What is this Building and What Does it Have to do with Fish?

Despite the recent heavy rains, the crews at the Calaveras Dam Replacement Project have been pouring concrete for an important feature of the future Dam – the stream maintenance building, pictured below.  The new building stands 25 feet tall and is located downstream at the toe of the future replacement dam.

We at the SFPUC will be releasing water from the future Calaveras Dam to support fish in the Southern Alameda Creek Watershed.  What’s that have to do with this building?  A lot, actually.  The stream maintenance structure provides a place for water discharged out of the future Dam to be collected and then discharged in a controlled manner to the nearby Creeks to support fish habitat. Water will flow from the reservoir to the structure via two 30 inch diameter pipes. Water will exit the structure over grouted rip rap to prevent erosion.

The Calaveras Dam Replacement project is more than 80% complete and expected to be completed in mid-2019.

Photo Friday in the Sunol Valley

Today we thought we’d combine two blog traditions - Photo Friday and Throwback Thursday.

Here’s a photo of how we used to transport water transmission pipe when Calaveras Dam was under construction in 1912.

Here’s a more recent example from a Water System Improvement Program (WSIP) project elsewhere in the Sunol Valley in 2012.

The water system that serves our customers is almost 100 years old in places, and less than 1 year old in others.  We will continue to upgrade crucial portions of the system through the $4.8 billion Water System Improvement Program and beyond through our 10 year Water Capital Improvement Program.

Have a great weekend everyone. See you around the Valley!