Every day in Sonoma County, thousands of people pass in and out of masonry buildings that could be at risk of collapse in an earthquake, a danger that persists three decades after a state law required cities and counties to address the hazard.
While Santa Rosa, Sonoma, Healdsburg and Petaluma have managed to retrofit most of these high-risk buildings for seismic safety, Sonoma County officials say there are about 170 in unincorporated areas, from Geyserville and the Russian River area to Penngrove, including retail shops, offices, fire stations, restaurants, schools, post offices, churches, meeting halls, warehouses, night clubs and wineries.
Some are landmarks and cherished historic structures; others are nondescript, utilitarian buildings. Some are in use nearly every day, and others appear to be shuttered. They are built of brick, stone or cinder blocks mortared together, largely without the connective strength of steel rods required for decades by building codes to hold structures together.
There are 7,800 of these structures — officially dubbed unreinforced masonry buildings, or URMs — in 29 counties, and they are at “significant risk of collapse,” according to the state Seismic Safety Commission.
The magnitude-6.0 temblor that struck a week ago today in southern Napa County focused new attention on California’s unfinished business with URMs, designated as a threat to public safety in a 1986 law that required cities and counties to inventory the buildings and develop remedial programs.
‘A huge success story’
The quake, which rattled Sonoma County residents — and people living more than 100 miles away — at 3:20 a.m. Aug. 24, hit hardest in Napa County, with damage and economic losses expected to hit $1 billion, according to an initial estimate by the U.S. Geological Survey. On Saturday, Sonoma County declared a state of emergency, estimating damages at $4.5 million, more than half to wineries. But most of the damage has been to contents rather than the buildings, and one owner of a retrofitted brick hotel in Glen Ellen was ecstatic with the way her structure fared.
“I’m happy to say, so far, we sailed through it,” said Christine Hansson, co-owner of the 107-year-old Hotel Chauvet, a three-story landmark in Glen Ellen. “It’s a huge success story.”
A few drawers slid open and some pictures were knocked askew on walls, Hansson said after inspecting the building, which has been converted to six condominium units. The elevator was running, the swimming pool intact and there was no structural damage, she said.
The yellow brick hotel, left vacant for two decades, partially collapsed in 2004, prompting Hansson and her partners to spend about $300,000 on renovations, gutting the building and bracing it from top to bottom.
“It’s expensive, but it was worth it,” Hansson said. “And the building is there to say it.”
Tennis Wick, director of Sonoma County’s Permit and Resource Management Department, ranks the Hotel Chauvet among the county’s notable seismic retrofit projects. Much work remains to be done, however, elsewhere across the region.
In 2006, the county identified 315 URM buildings and had whittled the number down to 204 by the time last Sunday’s temblor struck. The quake “gave us new urgency,” Wick said last week, after dispatching inspectors to check the buildings — with the owners’ permission — and assure all are posted with warning notices regarding their condition.