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!

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.

Historic Unfailing Dam Ready for Next 130 Years

                                          Lower Crystal Springs Dam after the 1906 Quake

It was built to last. The 1888 Lower Crystal Springs Dam, situated next to the San Andreas Fault,  survived two major earthquakes—the great earthquake of 1906 and the Loma Prieta in 1989—with no damage.  A critical recent upgrade plus our vigilant 24/7 operation ensure that the historic 175-foot-high dam is able to safely contain Crystal Springs Reservoir drinking water even in a year of record rainfall.

The main upgrade under the Water System Improvement Program was the widening of the spillway—an emergency device for the safe release of water during heavy rains—on top of the dam. The new expanse gives us the ability to release 2.5 times more water than before—if necessary. But again, a spillway is an emergency feature---and one that we haven’t had to use for decades, according to SFPUC Local-Regional Water System Manager David Briggs. 

The real safeguard is the day-to-day monitoring, anticipating and adjusting by our system operators.  They open valves to release controlled amounts of water into San Mateo Creek, and divert water northward to San Andreas Reservoir (at left), on to the Harry Tracy Water Treatment Plant (below), and then to customers. They continually forecast the anticipated amount of rain and runoff into the reservoir and assess that inflow’s impacts on reservoir level.  As needed, our operators will  release controlled amounts of water from the dam—but always taking into account the timing of high tides coming up the creek from the bay.   

We’ve been releasing water from the reservoir this way all winter, and have not come close to spilling water over the dam. 

The San Mateo Daily Journal talked with Briggs a couple of weeks ago.  You can read more on what he had to say about the safety of historic Crystal Springs Dam and our regulation of the water system here. 

Increased Truck Traffic on Friday Nights thru Saturday Days (Approximately 6PM)

Continuing tomorrow night and for the next three Friday nights (through September 3rd), increased truck traffic will be present on Black Mountain Road, Skyline Blvd., Crystal Springs Road, and Polhemus Rd. near the southern trailhead to the Sawyer Camp Trail.

On Friday, August 19th at 11 p.m., trucks will be delivering cement for the continued foundation pour at the base of the Lower Crystal Springs Dam. Truck traffic will continue throughout the night, and throughout Saturday day.

The work will enlarge the dam’s stilling basin (see photo) to ensure any spillway flows are slowed as they enter San Mateo Creek.

Please call our 24-hour answering service if you have any questions or concerns. You can also receive email alerts about construction in the Peninsula Watershed by subscribing to www.sfwater.org/SCT or follow us on Twitter: @SawyerCampTrail.

Lower Crystal Springs Dam Project: Informational Meeting on November 16, 2010

Please join us for an informational meeting about the Lower Crystal Springs Dam on Tuesday, November 16th at 7 p.m. The meeting will be held at the Hillsborough Town Hall at 1600 Floribunda Avenue.

San Mateo County has recently closed the Skyline Bridge (on top of the Lower Crystal Springs Dam between Crystal Springs Road and Bunker Hill Drive) to begin demolition work.

Hetch Hetchy Regional Water System construction projects will begin shortly near the dam and the Sawyer Camp Trail. You may contact us with questions or comments 24 hours a day at (866) 973-1476.