The work to be done consists, in general, of constructing a new replacement 626 foot long by 51.5 foot wide cast-in-place, post-tensioned concrete bridge on top of the Lower Crystal Springs Dam that will be installed approximately seven feet higher than the previous bridge due to the work completed by the San Francisco Public Utilities Commission (SFPUC) to raise the parapet wall on the dam. The previous bridge has been demolished and removed from site. The work to be done includes construction on the top of the existing dam. The top of the dam may be potentially moist and some of the Contractor’s work will involve dewatering. The work to be done includes excavating behind the existing Abutment 8 to remain and may include removing a portion of the top of the existing Abutment 8. Also, existing minor remnant portions of Abutment 1 may require removal. Utility coordination work to be done includes installing conduit support brackets for a PG&E conduit for the 230 kV electrical transmission line and also includes coordination with PG&E’s construction crew for the installation of the 230kV electrical transmission line under the bridge and at the bridge approaches; and constructing a worker access catwalk for the SFPUC. Additional work to be done includes grading, drainage facilities, paving, and vista point area parking lot improvements.
Crystal Springs Dam Bridge
The Contractor, Kiewit Infrastructure West, officially began work on February 16, 2016. To date, Kiewit has installed construction trailers, environmentally sensitive area fence to keep endangered species out of the active work zone, construction access ramps from the roadway to the top of the dam, and installed safety measures on the spillway of Lower Crystal Springs Dam for worker access and protection. The first bent (Bent 4) has been framed, the rebar cage (structural steel), and concrete installed. Bent 4 is constructed over the spillway of Lower Crystal Springs Dam.
Bridge construction is anticipated to be completed by October of 2017.
Kiewit Infrastructure West