Wednesday, March 13, 2019

Watch for Construction Trucks Crossing Sawyer Camp Trail at San Andreas Dam through April 5

The SFPUC is conducting geotechnical work on the west side of the Peninsula Watershed. The site is well out of public view, but vehicles will occasionally drive along a short part of the Sawyer Camp Trail where it crosses the San Andreas Dam, about one mile from the north entrance. We expect this work to continue through the first week of April.

The trail will remain open, but please watch for the trucks in the San Andreas Dam area. Thank you in advance for your cooperation and understanding. 

Friday, February 15, 2019

Weed Control Near Sawyer Camp Trail--First of Several Projects Now Complete

San Francisco Public Utilities Commission crews recently launched a series of short projects to control invasive weeds on parts of its Peninsula Watershed land near the Sawyer Camp Trail for approximately a one-mile stretch slightly north of Mile Marker 1. The first project, which started Monday, February 18, is now complete. The trail remained open throughout the work period.  

The weed control is being done to preserve and enhance the native grasslands that were seeded in late 2016 as part of a continuing long-term habitat restoration program in various areas throughout the watershed.  The 2016 seeding followed the removal of acacia trees and other large, invasive vegetation that had displaced the watershed’s historic native habitats near the trail and at other watershed sites.

Subsequent intermittent short periods of weeding and other vegetation control measures will occur in the Sawyer Camp Trail area in the course of the next couple of years or more. Trail users will be notified in advance.

The approximately 36-square-mile Peninsula Watershed is home to a diversity of long-time coastal habitats, ranging from conifer and oak forests to chaparral, grasslands, and marsh. In all, they harbor an abundance of native plant and animal life, including a high concentration of rare, threatened or endangered species. The watershed is also a State Fish and Game Refuge. 

Friday, February 8, 2019

The First Crystal Springs Bridge

The Lower Crystal Springs Dam across San Mateo Creek went up in 1888, and the first bridge on top of it opened soon after.

The narrow wood-planked crossing easily accommodated the horse-drawn vehicles of the time, and members of the Association of Civil Engineers soon turned out in force to inspect and celebrate.      

The new dam secured an additional welcome supply of more fresh, clean Peninsula water for thirsty San Francisco to the north. And the inventive gravity-arch structure itself, built of staggered interlocking concrete blocks, has lasted without fail ever since. It survived unimpaired the next two major earthquakes of 1906 and 1989.

Lower Crystal Springs Dam stands 149 feet tall on a 176-foot-wide base. The SFPUC recently upgraded it to ensure safe discharge of reservoir water during high rain periods. The more
contemporary bridge of the 1920s was removed just beforehand, with plans to construct a more seismically stable one in its place. 

The new 21st-century bridge opened this past January 11.  

Today Upper and Lower Crystal Springs operate as one reservoir and have a combined capacity of 22.5 billion gallons of water. The stored stream runoff, rainfall and surplus Sierra Nevada waters are continually drawn on as an essential local supplement to the Hetch Hetchy drinking water we serve throughout the Peninsula and San Francisco. 

Friday, February 1, 2019

Life on the Watershed: When Birds of Different Feather Flock Together--Look for Winter Activity along the Ridge Trail

February is still a good time to catch winter’s unique activity in the woods, where a single quiet tree can suddenly become a hub of fluttering, chirping commotion. 

This  is the season when songbirds of various sizes and colors band together in flight and feeding. They'll descend in mass on one or a couple of trees to feast on insects from leaves or the bark.  Each species has its own way of foraging (depending on bill size, shape, and other features), so that many of them are after different specific foods and coexist with less competition.

And there’s strength in the numbers, since flocking in a large group makes it harder for hawks and other predators to target a specific bird.  

Good places to catch a winter feeding frenzy are stands of our native coastal live oaks, especially in the mornings.

You can get well into the Peninsula Watershed woodlands by signing up for one of our Fifield-Cahill Ridge Trail hikes. There’s something scheduled for almost every weekend through March and into April. Events range from easy 5-mile round trips to brisker hikes across the 13-mile length of the trail.  For more information, and to reserve your space on line, please visit   

The 36-square-mile Peninsula Watershed has been protected since the late 1800s to safeguard the
quality of our local drinking water resources. A key side-effect is that the place remains an oasis of historic native habitats that support a diversity of plant and animal life, including 165 bird species, 50 different mammals, and 30 reptile or amphibian species. The SFPUC continually works to enhance the indigenous wetlands, grasslands, forests and other ecosystems by removing the non-native trees, shrubs and weeds that spring up, and replacing them with seeds or saplings from the original species.  

Friday, January 25, 2019

Crystal Springs 10-Year Challenge

Many a brave person is participating in the #10yearchallenge these days. Posting a photo from 10 years ago and a current one side by side on your favorite social media platform.

We at the San Francisco Public Utilities Commission are not shy about how much we’ve changed in 10 years, and thought we’d join in on the fun with Lower Crystal Springs Dam and Reservoir.

May 2008

This photo was taken in 2008 and shows Lower Crystal Springs Dam on the left, Skyline Bridge on top, and Lower Crystal Springs Reservoir and the watershed in the distance.

January 2019 (Ok, technically a little over 10 years)

What a difference a decade makes! Taken in January 2019, this photo shows Lower Crystal Springs Dam and the new parapet wall constructed to allow for safer release of high flows over the Dam. The upgrades are clearly visible in the lighter concrete color. Also clearly visible is the recently-opened new Skyline Bridge.  

What is conspicuously absent? The power poles. The upgraded power lines were placed underneath the new bridge.

Otherwise, the environs around Crystal Springs Reservoir are not showing their age at all.

We are firm believers that some views get better with age….

Have a great weekend everyone!

Friday, January 18, 2019

Photo Friday from the Crystal Springs Reservoir

We were thrilled to join the San Mateo Department of Public Works and San Mateo County Parks to open Skyline Bridge over Lower Crystal Springs Dam last Friday, January 11th. The new bridge, and the pedestrian lane on top of it, connect to a new trail section south of the dam.  

For those of you who haven't had the pleasure of visiting the region's newest bridge and trail section, you're in luck. We happened to take a bunch of photos of the bridge and the stunning Peninsula Watershed around it.

Happy Photo Friday and have a great weekend!

The new Skyline Bridge, atop Lower Crystal Springs Dam, has a separate trail for pedestrians.

View of the protected pedestrian lane on the bridge, Lower Crystal Springs Dam beneath it, and Crystal Springs Reservoir.

The new southern section of trail is now open to the public where it connects to Skyline Bridge.

Tuesday, January 8, 2019

Crystal Springs Dam Bridge Opens January 11

The County of San Mateo is inviting pedestrians and bicyclists  to experience the new Crystal Springs Dam Bridge on Friday, January 11 at 2 p.m. They will have a unique view of the bridge and connecting trails before the road opens to vehicle traffic at approximately 4 p.m. that day.  Scheduled speakers include Senator Jerry Hill and San Mateo County Supervisor Carole Groom.
The bridge opening also provides access to a new segment of the Crystal Springs Trail that is just under one mile long and offers additional views of the Peninsula Watershed. The trail ends just north of Highway 92 and Skyline Boulevard.
A shuttle service will be available to transport event attendees to the bridge from the Youth Services Center at 222 Paul Scannell Drive in San Mateo beginning at 1 p.m.  No on-site parking will be available at the bridge itself. Bicyclists are welcome ride to the site or use the shuttle service which can accommodate bikes.