2024 California Best Projects
Award of Merit, Water/Environment: City of Foster City Levee Improvements Project
Photo courtesy Tanner Pacific
City of Foster City Levee Improvements Project
Foster City, Calif.
Award of Merit
Submitted by: Tanner Pacific Inc.
Owner: City of Foster City
Lead Design Firm: Schaaf & Wheeler
Construction Manager: Tanner Pacific Inc.
Civil Engineer: Schaaf & Wheeler
Structural Engineer: Biggs Cardosa Associates Inc.
Contractor: Shimmick Construction Co.
When FEMA determined that the Foster City levee system did not meet minimum requirements for flood protection, this $72-million improvement project moved forward with several goals: increasing the height and width of the levee to improve protection against storm/tide surges, meeting sea level rise projections through the year 2050, providing resilience against a 100-year flood hazard and making the levee more resistant to earthquakes.
Construction scope included 6.5 miles of flood protection improvements adjacent to the San Francisco Bay and several tidal sloughs along existing levee and floodwall alignments. Crews installed 22,100 linear ft of steel sheet pile floodwall, more than 4,000 linear ft of concrete floodwalls and mechanically stabilized earth retaining walls as well as more than 5,000 linear ft of embankment construction using earthen fill and lightweight cellular concrete. The project also included three design-build bridge structures for pedestrians and vehicles, pavement, landscaping, irrigation and recreational amenities along the San Francisco Bay Trail.
As originally permitted, the project divided the entire alignment into seven segments where no two adjacent segments could be under construction at any given time. The project team recognized a full closure of the levee top trail was unrealistic during the pandemic. After coordinating with stakeholders, the project team identified a bypass that allowed for a full closure of the levee while providing a temporary rerouted trail to meet community needs.
However, environmental permits limited contractor access to some areas of the levee during shorebird breeding periods. So, the team created a three-phased levee closure with interim milestones for each phase. This allowed for construction to proceed in a more efficient, linear process, and the project ended on time and within budget in October 2023.
