As you sit under a two-ton chandelier in ballroom of the Hilton in Union Square during the Seismic Risk Mitigation Leadership Forum, you may look up and wonder…is San Francisco well-enough prepared for a major earthquake? The U.S. Geologic Survey estimates there is a 63 percent chance that a major earthquake – one of magnitude 6.7 (roughly the same magnitude as the 1989 Loma Prieta Earthquake that caused extensive damage and 63 deaths across the Bay Area) or greater – within the next 30 years.
But despite the precarious situation we’re contemplating in the Hilton ballroom, it’s likely you would be safer during a major quake inside that 46-story steel frame skyscraper than inside one of the many thousand smaller and less resilient buildings that house many of the city’s lower-income residents. Although San Francisco and other cities in the area are likely better prepared for an earthquake than any other region in the U.S., there is still a great risk that much of the affordable housing in the Bay Area would be lost indefinitely if “The Big One” struck.
Many of the more affordable housing developments in San Francisco include unreinforced masonry buildings and “soft-story” buildings (buildings with many openings – like garage doors or large windows – and a lack of interior partition walls on the ground floor) – two building types that are particularly prone to damage during an earthquake. A study included in the Community Action Plan for Seismic Safety found that there are some 2,800 vulnerable soft-story residential buildings in the city, many of which house lower-income residents and would likely be destroyed or rendered unlivable by a major earthquake. What’s more, there are an estimated 125 permanently-affordable housing developments in San Francisco that are also highly vulnerable. In the aftermath of a major earthquake, this all adds up to thousands of lower-income residents with potentially no place to live for the foreseeable future.
And though it’s often the focus of earthquake research and risk mitigation efforts, the West Coast isn’t the only part of the country at risk. The less active, but still threatening, New Madrid seismic zone in the central U.S. could produce a major earthquake in the Midwest and central Mississippi River Valley in the not-too-distant future. Given a lesser focus on earthquake-resilience in residential structures in that part of the country, the dangers to residents – particularly low-income residents – could be even greater if a major or even moderate earthquake were to strike the central U.S.
In the coming months, The Center for Housing Policy will be working with the RenaissanceRe Risk Sciences Foundation to explore the issues lower-income households face during earthquakes, along with solutions that can help mitigate the risk for this segment of the population. Much of this work will result in new content for HousingPolicy.org’s Housing & Natural Disasters toolkit.