To Recover from a Major Earthquake, SF Needs Housing Now, Not Just Later
If you think the shortage of homes is a crisis today, wait till the Big One hits. Retrofits are going well but will only take us so far.
There is a 72 percent chance that a magnitude 6.7 earthquake or higher hits the Bay Area in the next two decades. That means more than a fifth of San Francisco’s housing could be damaged or destroyed in a matter of minutes.
In a city already mired in a housing shortage, that loss of homes could create an unfathomable affordability crisis.
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The good news is that some researchers and city leaders are assessing the lessons learned from past earthquakes and creating a strategy for the next “Big One.” That strategy has led local officials to help retrofit the thousands of aging buildings in SF, home to some of the oldest housing stock west of the Mississippi.
It has also led to calls to build more housing, in part because new development follows modern building codes that are more resistant to temblors. (California makes code updates every three years, and cities must adopt them.)
This emphasis on housing — fixing what we have and building more — comes from a more holistic approach to earthquakes. Instead of focusing only on the dry numbers of dollars and damages, researchers are considering how people might actually respond at a neighborhood level.
For example, the 1989 Loma Prieta earthquake, with its epicenter in the Santa Cruz Mountains, completely destroyed 35 buildings in the Marina district. But homes that were structurally unaffected were often uninhabitable, because utilities were knocked out. That displacement isn’t recorded in the typical statistics covering the quake’s impact. Neither is the impact on the number of commuters who had to adapt after the jolt crippled the Bay Bridge for about a month.
Learning from each past disaster and improving the response accordingly is a central part of the city’s preparedness plan, according to Brian Strong, SF’s chief resilience officer and director of the Office of Resilience and Capital Planning, which works with other city agencies on long-term preparedness. That includes a range of housing policies — everything from retrofitting to designing strategies that would let residents shelter at home in the days after a quake. “Housing is a key priority for us in the city, and affordable housing especially,” he said.
Learning by shaking
The great April 18, 1906 San Francisco quake and the resulting fire still loom large in the city’s disaster plan. Cumulatively, the quake and fire destroyed 80 percent of the city. Following the disaster, the U.S. Army worked with the city to build tents in public parks to offer emergency shelter. As winter approached, relief crews then built small, one-story buildings known as earthquake shacks to provide more long-term housing. Some of these dwellings today sell for more than $1 million.
One key reason for the destruction in 1906 was that the quake had damaged the water system. In response, the city rolled out an auxiliary system in 1913, separate from regular fire hydrants, to let firefighters work even if some pipes broke. (In 2020, voters approved $153.5 million as part of a larger public safety bond to upgrade the system in the western neighborhoods.)
As of 2017, fewer than 5 percent of San Francisco homeowners had an earthquake insurance policy.
The Loma Prieta quake in 1989 was the first big test of the city’s resilience. Although it was considerably smaller than the 1906 temblor, fires broke out and 9,202 housing units became uninhabitable. Older, multistory buildings with open ground-floor plans suffered the most damage.
Since 2013, these older buildings, commonly known as “soft-story” units, have been the target of a citywide program to add additional walls and steel frames for protection. According to Strong, the retrofitting is going well: “We’re at 85 percent compliance, which is extremely high. That will ultimately result in 114,000 people in safer housing.”
Retrofits in your neighborhood: San Francisco began a retrofit program of soft-story buildings in 2013. SF’s chief resilience officer says the program has reached 85 percent compliance.
How to read this map: Blue areas, built on landfill or softer soil, have higher liquefaction risk. Yellow areas have higher landslide risk. Red dots are buildings not yet retrofitted. White dots are completed retrofits.
A deeper dive: Click here for an interactive version and zoom into block-by-block detail. Click here for methodology.
(Design: @burritojustice Data: SFGov.org)
The last major earthquake to shape current policy struck Los Angeles in 1994. “Insurance companies lost their shirts,” said Janiele Maffei, chief mitigation officer with the California Earthquake Authority (CEA). The private insurance market panicked with the number of damage claims, so the state created the CEA to provide a layer of government funding and support, as well as encourage insurance providers to stay in the market. Instead of including earthquake insurance in a general package, insurers now offered it separately and at an independent price.
But that price is steep. As of 2017, fewer than 5 percent of San Francisco homeowners had an earthquake insurance policy.
Displacement and migration
We’re doing a good job fixing many of our old buildings. But the current housing crisis adds a new dimension to preparedness planning. According to the state’s latest mandate, SF needs to build about 82,000 new homes by 2031 to stabilize its skyrocketing housing costs. That’s about the same amount of housing that could be damaged in a big quake — with 11,000 units of those units lost forever.
Put another way, in a city with 2.3 residents per housing unit, a major earthquake could displace as many as 200,000 people in an already stressed market.
Laurie Johnson is an urban planner and an earthquake expert who has modeled these kinds of scenarios. She suggested that some people will migrate east and south to places like Sacramento, Modesto, and Salinas after a major earthquake in the Bay Area. “In a really big event,” Johnson told The Frisc, “We’re going to end up looking for capacity in L.A.”
Soft-story retrofitting could bring the displacement numbers down, but the city has built aggressively on landfill in the past few decades. That ground is more susceptible to shaking and could result in more damage than expected. SF has nearly 1,800 census blocks that intersect seismic hazard zones. Those blocks contain 136,680 housing units — and potentially a third of our total population. (See map below.)
Density and risk: San Francisco is the second densest U.S. city. Some of its densest neighborhoods are in areas with higher seismic risk.
How to read this map: Blue areas, built on landfill or softer soil, have higher liquefaction risk. Green areas have higher landslide risk. The darker the city block, the higher the population density.
A deeper dive: Click here for an interactive version and zoom into block-by-block detail. Click here for methodology.
(Design: @burritojustice Data: U.S. Census via Census Reporter, SFGov.org)
Other disasters provide case studies for migration. Many residents affected by the 2018 Camp Fire that decimated Paradise, California, wanted to stay nearby and return as soon as possible, according to Kathryn McConnell, a doctoral candidate at the Yale School of the Environment. “Housing access really dried up right after the fire given the huge influx of demand,” she told The Frisc in an email.
House and rent prices climbed in neighboring Chico, enabling those with the highest incomes to relocate in the area while others had to move farther away. Beyond the Golden State, housing prices in New Orleans five years after Hurricane Katrina remained 33 percent higher than before — making it harder for low-income families who had evacuated to come back. Johnson, who also studied Katrina, noted that in New Orleans there was a “sacred triangle” of resources that people needed to return: housing, jobs, and schools.
Evictions from damaged structures, repair delays, red tape: The surest way to prevent these challenges is to retrofit thousands of buildings and avoid damage in the first place. The other way is to build more housing.
Although every city and every disaster are different, these scenarios still serve as warnings for San Francisco.
In a 2017 report, Johnson partnered with U.S. Geological Survey researchers to map the social impact of a potential rupture of the Hayward Fault, which runs under the East Bay. The report estimates that a neighborhood could lose 20 percent of its infrastructure, like buildings and utilities, before it witnesses a mass exodus.
One metric to evaluate migration in San Francisco is the COVID-19 pandemic. From early 2020 to the fall of 2021, SF lost approximately 8 percent of its population, according to the SF Chronicle. Many of the long-term effects on the city’s culture, businesses, and housing market remain in flux and are difficult to analyze. While the pandemic didn’t physically destroy infrastructure as a quake would, it certainly caused economic damage and palpable disruption — and it may suggest that SF can withstand some population loss after a quake and retain a semblance of its former self.
Coming home, staying home
While experts debate the effects of outmigration, San Francisco’s plan is to enable 95 percent of residents to shelter in place post-quake, or at least stay within their neighborhood or city limits. Hitting that goal will likely require more work today, pre-quake — more retrofitting and more new housing — as well post-quake emergency actions.
After a quake, the city could allow extra inspectors to quickly approve renovations. “We don’t want someone waiting around six months to do an earthquake repair.”
— David Bonowitz, structural engineer
No matter what, we’ll need temporary shelter. One unpublished study by a group of students and faculty from the Harvard Kennedy School in 2014, which Johnson and others cited, estimated that the city will need 68,000 units, including trailers throughout the city and cruise ships docked in the bay to house relief workers.
We also need to do political work now that makes post-quake recovery easier. For example, housing advocates (like SPUR, which issued a report on the aftermath of an earthquake 10 years ago) want legislators to create policies to let homeowners fix their homes quickly following a disaster. Accordingly, the Department of Building Inspection created a special program to bring in state inspectors and deputize private engineers to give buildings an all-clear as soon as possible after a quake. “We don’t want someone waiting around six months to do an earthquake repair,” said David Bonowitz, a structural engineer and an advisor to the SPUR report.
Another change could be new habitability standards to let people shelter at home. In other words, residents could stay home without water, electricity, or sewage assuming they could access those resources nearby, like with a porta-potty or at a public library or YMCA. (That said, any building code or inspection changes will be more difficult to pursue with the Department of Building Inspection reeling from a corruption scandal.)
Tenant advocates hope lessons learned during our most recent disaster, the COVID pandemic, will carry over to an earthquake. Tenants in damaged rent-controlled units will face two different scenarios, said Joey Koomas, senior administrative law judge at the SF Rent Board.
In the first, the unit is damaged but habitable. The landlord can evict the tenant for up to 90 days to make repairs, but is required to pay substantial relocation costs. Because that qualifies as an “eviction,” the process is regulated and scrutinized by the Rent Board.
In the second scenario, the earthquake renders the unit immediately uninhabitable. This is not considered an eviction and is more nuanced. “Once the landlord repairs the unit,” added Koomas, “they have to offer the unit back — same rent, same lease terms.”
But the landlord has no deadline and doesn’t have to pay relocation costs. “While the unit is uninhabitable,” Koomas explained, the “tenant is kind of on their own.” If a landlord claims the entire building was destroyed, it’s seen as building a “new” unit and the old tenant is entitled to nothing.
The surest way to prevent these challenges is to retrofit the thousands of buildings that have not yet been addressed and avoid damage in the first place. The other way to help these renters is to build more housing.
Like Brian Strong, Laurie Johnson and her USGS coauthors agree that more housing, especially affordable housing with robust and modern building codes, will save lives and keep renters in the city. It’s the best way San Francisco can prevent displacement, both today and in the near future when the inevitable earthquake hits.
Adam Echelman is a San Francisco-based writer and nonprofit consultant.
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