On Washington coast, plans for safe havens from tsunamis
University of Washington researchers are working with residents of Ocean Shores and other low-lying parts of Grays Harbor and Pacific counties to plan a network of towers, berms or other structures that could be built to provide refuge during a tsunami.
Seattle Times staff reporter
Project Safe Haven: https://catalyst.uw.edu/workspace/wiserjc/19587/116498
Facebook page: http://www.facebook.com/ProjectSafeHaven
OCEAN SHORES, Grays Harbor County — The sign in front of the stone entry to this beach town says, "TsunamiReady Community." But Ocean Shores is ill-prepared to face the onslaught of waves that would be spawned by a big quake from a major fault zone just offshore.
Forecasters estimate there would be only about 15 to 25 minutes to flee. While the sign advises people to move to higher ground should the earth start trembling, many roads leading to safety would likely be impassable due to downed bridges and other quake damage.
"Your best fighting chance is to get out on foot, and for some in these communities, that would be highly unlikely. There just wouldn't be enough time," said Nathan Wood, a U.S. Geological Survey researcher who has studied tsunami risks in the Pacific Northwest.
The precarious plight of coastal residents in Pacific and Grays Harbor counties is detailed by Project Safe Haven, a federally funded effort by the University of Washington, state, tribal and local officials.
The researchers are mapping areas where people would be unlikely to reach high ground, and working with residents to plan a network of towers, berms or other structures that could be built as refuge from the floodwaters.
The risk to these communities results from an unfortunate mix of geology and geography.
The Cascadia Subduction Zone, a point of tremendous pressure where one of the Earth's plates dives under another, sits just off the Southwest Washington coast.
Geologists estimate that fault unleashes a massive quake off Washington's coast about every 500 years.
The last such earthquake, of roughly 9.0 magnitude in 1700, triggered a tsunami similar to the one that devastated coastal communities of northeast Japan in March.
"The most vulnerable community"
About 40,000 residents live in tsunami-prone stretches of a four-county area that wraps around the outer coast and into the Strait of Juan de Fuca, according to a U.S. Geological Survey study completed in 2008.
Researchers estimate that roughly a quarter of those residents may not be able to walk to high ground in the time between an offshore earthquake and the first tsunami wave, according to Wood.
Scientists forecast that in Pacific County up to 22 feet of water could sweep across some low-lying areas of Long Beach Peninsula. The tsunami could also curl into Willapa Bay and strike low-lying areas of Raymond and South Bend.
In Grays Harbor County, the waves would slam into Westport, as well as parts of Aberdeen and Hoquiam.
At Ocean Shores, up to 30 feet of water could inundate all but a few slivers of high ground on the six-mile-long peninsula the city is built upon.
In the aftermath of a quake, many people likely would be isolated by downed bridges that cover an extensive network of lakes and canals in the city of more than 5,500 residents.
"Ocean Shores is the most vulnerable community on the coast; I don't think there is any close neighbor," said Tim Walsh, chief hazards geologist with the state Department of Natural Resources.
"A ridiculous phrase"
Walsh said that the reassuring "TsunamiReady" sign was developed by the National Weather Service, signifying that the community has marked evacuation routes and met a series of other benchmarks.
Ocean Shores was the first community in the nation to get that certification. But the 2001 ceremony marking the occasion was disrupted by a protester saying the sign gave residents a false sense of security.
"There have been some complaints that it is a ridiculous phrase," said Walsh, who serves on a national tsunami-coordinating committee. In 2009, the panel considered, but then rejected, a move to change the wording.
On March 10, the Project Safe Haven team held the first of three meetings at Ocean Shores to talk about the threat, and start a discussion about the placement of evacuation structures.
By then, it had already done an impressive amount of research, developing a plan for Pacific County that included a calculation of just how far an average person in reasonable condition could walk in a 15-minute evacuation period — some 3,600 feet.
Towers and berms
The team also came up with some initial construction costs. A proposed berm, reinforced with rock walls and big enough to accommodate 1,000 people, could be built for $706,000. Towers, their height dependent on where they were built, could hold 100 people. The estimated cost for those is $107,000.
Jeana Wiser, a UW graduate student who led the outreach effort, urged the Ocean Shores residents to discuss where structures might best be located and how they could serve other functions. Towers, for example, could double as whale-watching outposts, and the side of a berm might form seating for an amphitheater.
The structures would be built to meet federal tsunami standards first published in 2008. Towers would be girded with rock to divert debris. They could also have stairways that would enable wheelchair access before breaking away in the floodwaters.
Nobody was sure when — or if — public money could be found to finance these structures. But a plan would be a big first step in that direction.
"A wake-up call for us"
The crowd of some 50 people, mostly retirees, listened politely.
Some were skeptical and a bit bemused about the ambitious plans. Someone joked about drinking a glass of wine and bidding the world farewell if that big wave ever arrived.
The meeting ended, and people headed home, where some turned on their televisions for the late-night news. In a bizarre bit of timing, the Japanese tsunami had just struck and newscasts were filled with horrific scenes of raging waters coursing through coastal towns and farm fields.
"The hair stood up on the top of my neck. I just got goose bumps," said Sallie Roth, a retired Las Vegas casino worker who settled in Ocean Shores five years ago with her husband. "I feel terrible for Japan. But it is a wake-up call for us."
At a follow-up meeting last week, some 80 people packed into a hotel conference room for a somber meeting. They spent most of their time circled around tables, poring over a preliminary plan for siting evacuation structures.
One man noted that a few residents, spooked by the Japanese tsunami, had already put their homes up for sale.
What about tourists?
Some wondered what would happen if the earthquake struck during a summer day, when the city population may more than double in size with tourists. Would there be enough room for everyone scrambling for safety?
What about the disabled still living in their own homes but unable to leave by themselves? Would people risk their own lives to help them out?
Others wondered if such structures would be built in time for the next big tsunami.
"We are a time bomb here," said Judy Dawson, a resident at the meeting. "We just have to hope it's not our time yet."
Hal Bernton: 206-464-2581
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