Friday, August 18, 2017

Photo Friday in Sunol Valley

This week we wanted to share a snapshot of construction underway at the Fish Passage Facilities in the Alameda Creek Watershed located adjacent to the East Bay Regional Park District's Sunol Regional Wilderness.

The photo below shows the construction of the intake structure were the fish screens are being constructed.  This particular intake structure will have a total of 4 fish screens (high tech contraptions that will prevent fish from being drawn into the intake structure).

The goal of the 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. 

This project is part of the San Francisco Public Utilities Commission's $4.8 billion Water System Improvement Program to repair, replace, and seismically upgrade portion of the Hetch Hetchy Regional Water System.

Construction is expected to be complete in fall 2018.

Happy Friday! 

Thursday, August 10, 2017

National Water Quality Month

August is National Water Quality Month! Your drinking water comes from a watershed. And if you are a customer of the San Francisco Public Utilities Commission (SFPUC) or one of our 27 wholesale customers in four Bay Area counties, your drinking water comes from three watersheds: the Tuolumne River Watershed near Yosemite National Park, the Alameda Creek Watershed in the East Bay, and the Crystal Springs Watershed on the Peninsula.

By protecting and preserving the lands that produce our drinking water, we not only support rare and endangered wildlife, we also provide the highest possible quality water to our customers.

In honor of National Water Quality month, we’d like to take this opportunity to remind ourselves how we all can help protect our local watersheds to protect the quality of our water.

The SFPUC owns 35,000 acres of watershed lands in the Alameda Creek Watershed. They are home to critters, like the Western Pond Turtle.

As part of National Water Quality month awareness, there are small things that you can do in your everyday life to help keep and protect water quality. Here are some helpful tips:
  • Use a commercial car wash — cleaning your car at home flushes dangerous chemicals down the storm drain and directly into our lakes and streams
  • Pick up after your dog
  • Dispose of used motor oil properly - one quart of motor oil can contaminate more than 250,000 gallons of water
  • Help pick up litter on the streets that could end up going down the storm drain use detergents that are phosphate-free 
  • Join in a beach, stream, or wetlands cleanup project. Look for local projects in your area.
By doing these simple things you will be contributing to protecting your watershed for future generations.

Thank you and Happy National Water Quality Month!

Thursday, July 13, 2017

Northern Rough-winged Swallow Chicks Relocated at Alameda Recapture Creek Project

During the month of June, part of our construction management team at the Alameda Creek Diversion Dam (ACDD) project relocated 5 adorable Northern Rough-winged swallow chicks.  The relocation of the chicks was done by lead biologist, Chris Pattison, with the assistance of another lead biologist, Matthew Bettelheim. Chris Pattison was the only biologist handling the baby chicks. The entire process was performed under a U.S. Fish and Wildlife (USFWS) relocation permit.

Lead biologist, Chris Pattison preparing to relocate the chicks

Rough-winged Swallow Chicks at ACDD Project

They were immediately transported to the Lindsay Wildlife Hospital for a full veterinarian examination.  All of the baby chicks passed their examinations and were then transferred to the Native Songbird Care and Conservation in Sebastopol, California.  Native Songbird Care and Conservation specializes in insectivorous birdsThe chicks were reared until they were ready for release.

Northern Rough-Winged at ACDD project

A plain brown bird, Northern Rough-winged swallows are common across the United States in the summer. They are solitary and are usually seen singly or in a small group.  The bird gets its name “rough-winged” because their outer wings have small hooks or points.

See you around the valley!

Thursday, July 6, 2017

Preventing Fires in and around our Watersheds

Calaveras Reservoir 

Happy belated Fourth of July!

We are in the middle of fire season and it’s good to keep in mind how we can prevent fires in and around our watersheds.  Our watersheds, the San Antonio and Calaveras reservoirs are a critical part of our infrastructure because they provide clean drinking water to millions of people in the Bay Area.  They’re also home to wildlife, fish and livestock. According to the Environmental Protection Agency, more than $450 billion in food, fiber, manufactured goods and tourism depend on clean, healthy watersheds. Today’s blog is a continuation of our summer fire safety series, focusing on preventing fire in and around our watersheds.

Image courtesy of

Fire Triangle

There are 3 key elements that need to be present in order to ignite a wildfire.  Those three elements are humidity, fuel (grasses, sticks, branches etc…) and wind.  Typically, if the humidity in the air is lower than 30%, coupled with fuel and wind, you’re bound to create a fire.  Out of all of the three elements, wind is the most dangerous because it provides oxygen to a fire. Wind not only controls the direction, spread, and size of fire, but also greatly affects the flammability of plants by reducing fuel moisture.

San Antonio Reservoir

Preventing Fires in and around Watersheds

Here are some helpful tips on how to prevent fires in and around our watersheds:
  • Be careful and stay in well established graded/mowed roads
  • If you have an ATV’s- remember just because you have an ATV doesn’t mean you’re safe 
    • Use ATV’s only if weather permits
  • Pay attention to the condition of the fuel around you, especially on hot, windy days
  • Be aware of your vehicle’s exhaust, whether you’re on an ATV, car or any other type of mechanical equipment
    • If you have to pull over to the side of the road, be careful not to park over dry fuel (grasses)
  • Fireworks- careful not to set them off in or around dry fuel (grasses)
  • Shooting Guns- sparks from guns or any other type of firearm can ignite a fire given the right conditions
  • Mowing –is the biggest causes of fires, try not to mow past 10 a.m.
  • No smoking near the watersheds
 If you see a fire near or around a watershed please call 911 immediately!

Additional fire resources:
·       CAL FIRE at:
National Fire Protection Agency,

Friday, June 30, 2017

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

See you around the Valley! 

Friday, June 23, 2017

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!

Friday, June 16, 2017

Bald Eagle Photo Friday at San Antonio Reservoir

Happy Photo Friday!

This week’s pick comes courtesy of Kevin and Pat from our Natural Resources and Lands Management staff.

We have spent a lot of time writing about the nesting pairs of bald eagles who reside at Calaveras Reservoir and the pair near our restoration sites near San Antonio Reservoir in the SFPUC-owned Alameda Creek Watershed. But we’d like to introduce you to a more recent arrival to the San Antonio Reservoir area.   

This pair has made its home closer to our Turner Dam at San Antonio Reservoir.  Since it is the time of year when our pairs are on their nests taking care of chicks, our staff spotted two eaglets in their nest.

Once bald eagles find a nesting location they like, they tend to stay in the area. Which is why these bald eagles and our Natural Resources and Lands Management staff have gotten to know one another.  Our staff monitors the well being of these birds on a weekly basis. They all have been trained on bald eagle monitoring and behavior. Knowing these particular birds and bald eagle behavior enables our Natural Resources staff to know quickly if the birds seem ‘off’ because they have been disturbed by something.  

These little ones will fledge (develop the ability to fly) anywhere from 8 to 14 weeks of age. For now, they’re being fed a consistent diet of fish found in the reservoirs and creeks within the Alameda Watershed.

Healthy watersheds provide high quality water and also provide a safe haven for many amazing plants and animals. We consider it an honor and a privilege to look after these watershed lands, and all who live there, too.

Have a wonderful weekend, everyone!