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!

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!

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 : https://www.landmsupplyco.com/

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!

Photo Friday - Morning Light

Happy Photo Friday

It's been a while since we posted any photos from Pat, one of our Watershed Keepers who helps look after our Alameda Watershed lands.

Recently Pat found himself at San Antonio Reservoir at sunrise and shared the moment with all of us. 

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

Alameda Whipsnake Sightings Near You

Here in the Sunol Valley we have a special species of snake that lives among us. It’s no other than the Alameda whipsnake or sometimes called the Alameda Striped Racer, (Masticophis lateralis euryxanthus), a subspecies of the California whipsnake (Masticophis lateralis). It has made the coastal scrub, chaparral, and grassland habitats in the hills east of the San Francisco Bay its habitat.

Known for its ability to move fast, the Alameda whipsnake has the following distinct features: broad head, large eyes and a long slender body with a distinct yellow-orange “racing stripe” down each side. Adults can grow to six feet long. They are diurnal which means that they are active mainly during the day. Surprisingly good climbers, these snakes seem to prefer to hunt for lizards, snakes, and frogs. They are not venomous and pose no threat to humans.

All of the workers on SFPUC-related construction projects in the Valley have been trained to be on the look out for these special snakes. If they see one, they stop what they're doing, and contact a trained biologist to rescue them to a safer location.



Here is an up and close picture of one rescued by our field biologist, Aaron.

November is the time of year when they look for a dry, safe burrow to hibernate during the winter. The springtime is when courtship and mating takes place, usually from late-March through mid-June.



Alameda whipsnakes are considered to be both a federally and state threatened species.









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!

Calaveras Road Closure Extended until December 31, 2018

The Closure of Calaveras Road to through traffic between Milpitas and Sunol has been extended from Friday, November 2, 2018 to Monday, December 31, 2018.

The road will reopen to all traffic, weekdays, weekends, and holidays starting Tuesday, January 1, 2019.

Why:

SFPUC has completed the repairs to last winter’s landslide and we are now working to obtain the necessary approvals to open Calaveras road to the public.

Background:
We have been working since 2011 to replace the 93 year-old Calaveras Dam to increase the reliability of the Hetch Hetchy Regional Water System, which serves 2.7 million people in four Bay Area counties.

The closure of Calaveras Road began in July 2016 to protect public safety on the extremely narrow portions of Calaveras Road while large trucks utilized the road for construction.  

Road Closure Details:
Where: Calaveras Road just south of Geary Road (entrance to Sunol Regional Wilderness) to Oakridge Road near the Alameda /Santa Clara County line.

When: 

July, 2016 through December 31, 2018. The Road will be open on weekdays, weekends, and holidays starting Tuesday, January 1, 2019.

For more information, visit sfwater.org/calaverasroad

Thank you for your continued patience. We apologize for the inconvenience.