A study in Washington state will look at how to make the highest-risk schools in the state safe from a major earthquake and ensuing tsunami.
Of approximately 2,000 K-12 school campuses in the state, consisting of about 4,400 permanent and about 4,800 portable buildings, about 200 of those are within a mile of an active fault, and 214 of those are in moderate to high liquefaction zones.
The state is spending a total of $1.4 million on a study of high-risk buildings in general, $1.2 million of which is going to the Department of Natural Resources (DNR) to study at-risk schools. The other $200,000 will be used by the Commerce Department to study unreinforced masonry buildings. It is estimated that approximately 185,000 buildings may be vulnerable.
“This study is a great step in the right direction for assessing schools for seismic risk,” said DNR Chief Hazard Geologist Corina Forson in an email. “The preliminary assessment will give us a better understanding of what we are looking at for school buildings across the state, but we still have a long way to go to understand seismic risk and what needs to be done to retrofit schools to bring them up to life safety standard.”
The state is at risk from a major earthquake from the Cascadia Subduction fault. A quake of magnitude 9.0 would trigger an accompanying tsunami that would stretch down the coast to California.
The Cascadia Subduction Zone has had a catastrophic quake every 200 to 600 years; the most recent one was 318 years ago. There are other faults that lie on each side of the state that pose about an 80 percent risk of a quake within the next 50 years.
Approximately 72 percent of Washington K-12 schools are considered to be in high-risk seismic areas, and about 11 percent are in medium-risk areas. Of the 2,000 schools, about 232 of them were built after 2005 and had upgraded codes incorporated in the buildings, but about 1,700 were built prior to 2005.
“So that means unless they’ve been retrofitted and upgraded to current seismic standards, they don’t necessarily meet the current standards,” said Robert Ezelle, director of the state Emergency Management Division, who met with Gov. Jay Inslee and other officials on the matter Wednesday.
Ezelle said he didn’t know the number of schools that had been retrofitted or upgraded. “That’s really one of the purposes for running this study,” he said. “To try and do an assessment as to how bad the problem really is.”
The study will be a “cursory” assessment to identify which of the 200 schools nearest the fault are at greatest risk and then do more in-depth engineering studies of about 20 schools. “That’s really all the funding will allow for,” Ezelle said.
He said those schools in the inundation zone are the ones at greatest risk. “Not only are they an earthquake hazard, but they are also at risk of being swept away by the ensuing tsunami. By the same token, we can’t only focus on those schools because there are schools in the urban core in fault areas housed in unreinforced masonry buildings, not retrofitted, so we need to look at those buildings as well.”
In Washington, 37 campuses are in the inundation zone, which translates to about 9,000 students. Some local residents secured $2 million in funding to build a vertical evacuation shelter in a school gymnasium. Ezelle said the result could be 1,000 lives saved.
“If you look at the actuarial value of human lives, the benefit greatly outweighs the costs of the investment,” he said. “It’s a matter of how do we incentivize and make it possible for other schools that are in the inundation zone to do likewise?”
The future costs of making the state safe are daunting. A preliminary assessment of all the schools would cost $10 million to $15 million, Ezelle said. “And if you threw $1.2 million per biennium at the problem, it would take about 20 years at the current funding rate to do that.”
He said additional money to do engineering studies on what it would take to retrofit would cost an additional $50 million to $75 million. “So if you look at $1.2 million per biennium, it will be 100 years to get all that done.”