Constructed in 1932, the Sixth Street Viaduct spans nearly 4000 feet across the river and is one of fourteen historic Los Angeles River crossing structures. However, due to a rare chemical reaction in the cement supports and seismic vulnerability, the Sixth Street Viaduct needs to be demolished and replaced. The City of Los Angeles, Bureau of Engineering is working in partnership with the California Department of Transportation (Caltrans) to design a new bridge. The design includes canted cable supported arches, providing an iconic “stress ribbon” throughout the length of the viaduct and access points for the community at the base of the arches, and community gathering space on either side of the river, as well as direct access to the river. The spectacular design of the new bridge and the many parks, open spaces, and community features on, next to and below the bridge, is bringing together a working collaboration of residents, elected officials, business leaders, schools, labor unions, cyclists, neighborhood activists and artists, never before seen in a public infrastructure project in Los Angeles.
Pacifica Services Inc. is providing environmental engineering and permitting support for the project to obtain the permits identified in the Final Environmental Impact Report (FEIR) necessary for construction, which include the Department of Fish and Wildlife 1602 Agreement for Stream Bed Alteration and Regional Water Quality Control Board 401 Certification for dredge and fill. Pacifica is contracted to provide estimating and construction management support, as well.