Road Closure Notification

Skyline Boulevard (Highway 35) between Crystal Springs Road and Bunker Hill Drive is closed as of Friday October 29, 2010, through January 10, 2019.  Pedestrians and bicyclists are invited to experience the new Crystal Springs Dam Bridge on Friday, January 11, 2019 at 2 p.m.  They will have a unique view of the bridge and connecting trails before the road opens to vehicle traffic at approximatley 4 p.m. that day.

There are four significant construction projects within the Crystal Springs Dam Bridge vicinity that both the County of San Mateo and the City and County of San Francisco (owner of the Lower Crystal Springs Dam) have been responsible for, and are listed below:

1.)    County Project – demolition and removal of the old bridge, which sat atop the Lower Crystal Springs Dam.  This work took 6 months and was completed in February, 2011.

2.)    City and County of San Francisco (CCSF) – Lower Crystal Springs Dam Improvement Project involving work on the top of the dam, which included increasing the height of the parapet wall by approximately 9 feet.  This work took approximately 17 months and was completed in May 2012.

3.)    CCSF - Crystal Springs/San Andreas Transmission System Upgrades Project involving construction work adjacent to the dam and within the vicinity of the dam.  This work took approximately 47 months and was completed in October 2014.

4.)    County Project – construct a new bridge on top of the Lower Crystal Springs Dam.  This project is estimated to take approximately two years.  The design for the bridge has been completed and the County has awarded the reconstruction project to Kiewit Infrastructure West (Kiewit).  Kiewit submitted the lowest responsive and responsible bid at $11,900,000.  Construction began in February 2016.

While the County had previously estimated a bridge completion date, the projects listed above are somewhat sequential and the bridge construction work could not commence until the CCSF completed their projects.  Now that CCSF’s work has been completed, the County is moving forward with reconstructing the bridge.

The County has also been coordinating with Pacific Gas and Electric (PG&E) and CCSF to include work in the County’s bridge project to accommodate their facilities.  This work will allow PG&E to relocate their high voltage overhead power lines (230kV Transmission Line Project) to the underside of the new bridge and remove their high voltage towers at each end of the bridge after the new bridge is constructed.  The required Agreements with PG&E and CCSF have been approved by the County of San Mateo Board of Supervisors, PG&E, and CCSF, which were necessary for the bridge project to proceed to bidding.

The County’s bridge replacement project is federally funded by the Federal Highway Administration with funds administered by Caltrans.  In addition to the complex nature of the bridge replacement design and construction and as outlined above there have been and will continue to be a significant amount of coordination required to complete the bridge project.  The project has incurred delays due to differing site conditions, construction related issues, and weather. 

The County has completed construction of the new bridge as of October 2018.

Construction of PG&E's 230kV Transmission Line Project has been completed.  For additional information regarding PG&E's work, please contact and (408)282-7517.

The County is currently putting in a recreational trail south of the bridge to provide a safe area for pedestrians to walk.  In addition, there is security fencing that needs to be installed in multiple locations within the project site and this security fencing has to be coordinated and approved by the SFPUC.  The current tentative schedule to complete the remaining work for the Parks trail and security fencing is the end of December 2018, pending sub-contractor availability and lead time to procure fencing materials given the current construction climate in the Bay Area.

The County will be reopening of Skyline Boulevard (Highway 35) between Crystal Springs Road and Bunker Hill Drive to vehicle traffic on Friday, January 11, 2019 at approximately 4 p.m.  The County appreciates your continued patience and will continue to update the County’s webpage regarding this project.