Friday, February 15, 2019

Willow Branches Everywhere

Biologist Aaron Sunshine planting Willows

Fully-Grown Arroyo Willow
The recent rains have done wonders for our reservoirs and watersheds. It also happens to be the ideal time for putting plants in the ground for environmental restoration of our Alameda Watershed Lands. 

Of late, our Calaveras Dam Replacement Project biologists have devoted themselves to willows. A total of 36 willows have been planted by the downsteam building of the newly-constructed Replacement Calaveras Dam alongside Calaveras Creek. The types of willows planted were red willows (Salix laevigata), Arroyo Willows (Salix lasiolepis) and Narrowleaf or sandbar willows (Salix exigua). All are native to California and to our watershed. 

There are approximately 400 species of willows worldwide. You don’t have to look far to find them, all you need is a good water source. That’s because willows like their roots to be very wet, and they prefer year-round moisture.

The interesting part of willows is that they are easy to propagate. An entire willow tree can grow from a single branch.

The best time of the year to cut and plant is during the winter, preferably in January. Our Calaveras Dam Replacement Project biologists harvested branches from willows within the watershed and planted them along Calaveras Creek as part of the project's restoration plan.

The willows will be monitored annually for the next five years to ensure that they are growing and thriving. 

Once fully grown, our willow trees will provide good nesting for songbirds such a as the Woodwarblers, Song Sparrows, and the California Towhees. The new trees and will also be a good foraging habitat and cover from predators for many species too.

See you around the valley!

Fully-grown narrow-leaf willow.

Friday, February 8, 2019

Photo Friday - Let it snow!

Calaveras Reservoir view from S. Calaveras Road

Snow is a a rarity among these parts of California.  This week the mountains and the valleys in Sunol were covered in it.  Here are some photos shared by our intrepid Watershed Keepers.

Photo courtesy of Kevin Woolen 
Taking a minute to enjoy the beautiful scenery.

Photo courtesy of Kevin Woolen
Our grazing tenants (cows) do their work against the rare backdrop of a snow-capped mountain.

Stay warm out there, and see you around the Valley!

Friday, January 25, 2019

Photo Friday - Newts!

Happy Photo Friday from the Calaveras Dam Replacement Project!

Even though the Replacement Calaveras Dam has reached its full height, our crews are still busy out there. And whenever our crews are working, so are our biologists. They are always on the lookout for critters who might have wandered onto the site.

Our intrepid team found this fellow recently climbing the wall of the dam’s spillway.

This is a California newt. Excellent climbers and land dwellers, these California natives are active during the day. They dine on small invertebrates like earthworms, snails, slugs, and crickets. They have few natural predators because they produce a potent neurotoxin in their skin (the same as pufferfish).  This is dangerous only if you eat them, however (predators take note).

Our biologists think this fellow was traveling to or from a body of water for breeding. The team placed it out of harm’s way in moist grass nearby, where he continued on his journey.

Lucky for us they had their camera handy.

Have a great weekend, and see you around the Valley!

Wednesday, January 2, 2019

Calaveras Road Reopens January 3, 2019

We are pleased to inform you that Calaveras Road between Geary Road and Felter Road will reopen to all traffic, weekdays, weekends, and holidays starting Thursday, January 3, 2019 at 10:00 a.m. 

Please note construction trucks and large vehicles will still be using the road, so please drive and ride with caution.

The San Francisco Public Utilities Commission (SFPUC), owner and operator of the Hetch Hetchy Regional Water System, is completing construction of a new dam to replace the former 93-year-old Dam at Calaveras Reservoir in the Sunol Valley.

Restoring Calaveras Reservoir is one of the most important projects of the $4.8 billion Water System Improvement Program. Calaveras Reservoir is the Hetch Hetchy Regional Water System’s largest Bay Area reservoir when it is full. Restoring its historic levels is crucial for water supply to 2.7 million people in the Bay Area in times of drought and emergencies. Construction on the earth and rock fill dam began in 2011.  Construction is scheduled to be complete in spring 2019.


For more information, visit

We thank you for your patience!

Friday, December 28, 2018

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!

Friday, December 21, 2018

Calaveras Dam - The Real 'Shark Tank'

Crews constructing the SFPUC’s new Calaveras Dam in the East Bay uncovered a geologic layer that happened to contain thousands of fossils. Through a cooperative agreement with the University of California Museum of Paleontology (UCMP; Berkeley, CA), those fossils are now being cleaned, analyzed, and catalogued.

“We transferred all of the fossil specimens to UCMP this year,” said JT Mates-Muchin, the SFPUC’s Environmental Compliance Manager who helped broker the agreement. “Fossils are a non-renewable resource. It is important that they are carefully catalogued and preserved for scientific research.”  

 A Megalodon Shark Tooth Being Scanned in the Lab.

The lead researcher and lab manager at UCMP, Cristina Robins, and her team are beginning to tease information out of the fossils.   Fifteen million years ago, the site of Calaveras Reservoir was located at the mouth of a vast inland sea that stretched into the Central Valley.  Just like in the seas of today, there was a lot of plant and animal life throughout. When they died, they left a fossil record.

This included sharks, lots of sharks. More than 2,000 shark teeth have been found from 35 species. These include many from requiem and mako sharks. Some teeth from the 35-foot megalodon shark have turned up as well. What do these shark teeth tell us?
  1. The area around Calaveras Dam was once completely submerged by water.
  2. The depth of the ocean could have been as deep as 700 to 1,000 meters.
  3. The distribution of species is similar to fossil locations as far as way at Gatun, Panama.
  4. Calaveras has a higher diversity of sharks than other sites.

At this point the paleontologists have only begun to scratch the surface of the Calaveras fossils, no pun intended.

The teeth from 35 different species of shark have been found at the Calaveras Dam Replacement Project.

We look forward to learning more secrets about the Bay Area’s past through these amazing fossils.

Keep up to date on the Calaveras fossils through the UCMPFacebook Page.

A 30 foot long predator left its tooth at Calaveras Dam. The Megaladon tooth is being analyzed at UCMP.

 See you around the Valley!

Friday, December 14, 2018

Floating Yellow Curtains

If you've seen one of our aerial photos of the Calaveras Dam Replacement Project, you might have noticed what look like yellow lines in the reservoir. Those are turbidity curtains. What's that?

We're glad you asked.  A turbidity curtain, also known as a silt curtain, is a floating barrier that collects suspended solids that are present in the water and allows them to settle in a contained area.

Calaveras Reservoir, and our turbidity curtains, are visible below.

Turbidity curtains are usually placed near areas were we have disturbed soil in or near the reservoir. The turbidity curtains act as a floating filter to protect the water around the outlet tower where we take water out of the reservoir. Although we filter this water at the nearby Sunol Valley Water Treatment Plant before we serve it to our customers, these curtains add an additional layer of protection to our water supply from any particulates or sediment from the Calaveras Dam Replacement Project.

The top of the curtain is made from a float from which a skirt hangs down. There are generally two types of turbidity curtains: hanging and standing silt curtains. At the Calaveras Dam Replacement Project we use hanging silt curtains.

Image curiosity of :

A close up of our turbidity curtains.

Turbidity curtains are an important part of the Calaveras Dam Replacement Project to continue to protect our our water sources during construction.

See you around the Valley!