Funding Sought to Complete Golden Gate's Seismic Retrofit
The final phase of a project to strengthen the 1.7-mile bridge against earthquakes and terrorism is expected to begin next year. Federal funding is being sought in a surface transportation authorization bill to be introduced in Congress next month.
Two projects to alter San Francisco's iconic Golden Gate Bridge are nearing milestones. One, a seismic retrofit project that has been under way for 17 years, is nearing the start of its final phase, with U.S. Rep. Lynn Woolsey, D-Calif., having requested $166 million to complete that phase from the surface transportation authorization bill that will be introduced in Congress next month. The other project -- for which no funding has yet been identified -- is the Golden Gate Bridge Physical Suicide Deterrent System Project, with a netting system chosen as the preferred alternative. Board members of the Golden Gate Bridge, Highway and Transportation District, which operates the bridge, approved a Memorandum of Agreement on May 22 that is a one of the final steps in the environmental approval process and in allowing this project to obtain federal funding.
The MOA is required by Section 106 of the National Historic Preservation Act. Once parties including Caltrans, the Foundation for San Francisco's Architectural Heritage, Golden Gate National Recreation Area, and the National Trust for Historic Preservation accept it, a Final Environmental Impact Report and Findings of No Significant Impacts can be finished. These are expected to be released to the public next month.
The transportation bill is a big one. The U.S. House Committee on Transportation and Infrastructure recently reported 405 members of both parties submitted 6,868 high-priority funding requests that total $136.3 billion.
The bridge's seismic retrofit is thoroughly detailed at this site. Phase 3B will cost $260 million, will begin in 2010, and will take 3.5 years to complete.
The decision to undertake seismic improvements was made after the Loma Prieta earthquake on Oct. 17, 1989, a 7.1 magnitude quake that did not damage the bridge. But the epicenter was only 60 miles to the south. Bridge managers commissioned a study that concluded an earthquake of 7.0 or greater magnitude with an epicenter near the bridge could damage it, causing an extended shutdown, and an 8.0 earthquake would pose a substantial risk of collapse of the San Francisco and Marin Approach Viaducts and also extensive damage to the main suspension bridge.
By April 2006, the seismic retrofit was far enough along that the bridge no longer faced a potential for collapse, but the risk of significant damage to the main suspension bridge remains until Phase 3B is finished.