Preparing LA buildings for the Big One

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Northridge Meadows apartment building several months after the 1994 Northridge Earthquake, 1994. Wikimedia

One of the most fatal sites during the earthquake was The Northridge Meadows apartment complex. The three-story stucco building with 140 units was right at the epicenter of the quake. It sat right atop a fault line that geologists did not even know was there. Sixteen people were killed when the top two floors of the apartment complex pancaked on top of the first. This was a “soft-story” building with tuck-under parking. Many are nicknamed dingbats.

There have been efforts to get those types of buildings retrofitted. In 2016 the City of Los Angeles passed an ordinance mandating retrofits of around 13,000 wood frame soft-story buildings. Many of the largest apartment buildings of this type were in the San Fernando Valley.

Los Angeles’ chief resilience officer Marissa Aho told DnA on ATC that since the program started, a total of 1,500 buildings have completed the retrofit process. Another 1,801 buildings has been issued permits by the DBS to begin retrofitting and then more than 4,551 additional buildings have begun the process by submitting plans.

But “orders to comply” have been issued for all of the 12,865 soft-story buildings that need seismic upgrades.

Aho says the city is making good progress.

“Yes, our most vulnerable buildings are being retrofitted. 61 percent of our soft-story buildings have started the process. The notices went out to the largest buildings first,” she said, “so, with the 1,500 buildings that are complete, those buildings hold 21,000 households that are safer today.”

The city’s mandatory retrofit program requires owners to either provide evidence that their structures have been retrofitted, or file plans to do so, within two years.

Aho said the city sent orders to comply to the owners of larger buildings first, so the retrofits would begin quickest for the bulk of the units that needed them. She estimates that it costs around $6,000 per unit to retrofit a building.

Ali Sahabi, engineer and owner of Optimum Seismic, a company that does seismic retrofitting, told DnA that this is money well spent, for reasons both humanitarian and economic. Rental properties provide their owners with a strong and steady source of income, which is lost if the building collapses.

Last year Mayor Garcetti issued the Resilient Los Angeles report, which outlined the city’s preparedness goals, including earthquake planning.

There was also an app launched earlier this month called ShakeAlert LA that notifies you if an earthquake occurs that’s 5.0 or greater, giving you a few extra seconds to prepare.

But this is a really important issue. Earthquakes are always out of sight, out of mind, but a team of scientists from the U.S. Geological Survey estimated that LA’s next big earthquake could displace 270,000 people.