Coastal Communities Make Preparations for Inevitable Cascadia Tsunami

Tsunami warning signs are plastered along Highway 101, the road that runs down the Pacific Northwest coast. The highway continuously zigzags down to sea level (tsunami hazard zone) and then climbs back up onto seaside bluffs (safe from tsunamis). Ever since I started studying earthquakes I have been hyperaware of these signs whenever I drive down the Oregon coast. And when I am on the beach, I make sure to know the quickest route to high ground.

When the Cascadia earthquake (i.e. the “big one”) hits the Pacific Northwest, the tectonic plate that includes North America will jolt seaward, flicking up large volumes of ocean water and creating a tsunami.  Approximately 15-20 minutes after the shaking stops, the tsunami will slam into the coast. Wave heights could be 30 feet or more, higher than a two-story building. Unlike regular ocean waves that steadily advance and retreat, the tsunami will look more like a giant wall of salt water, sand, and large debris. Though a wooden-framed house will likely withstand the shaking from the Cascadia quake, it is unlikely that it will endure the impact of so much water.

In Japan, the tsunami triggered by the March 2011 earthquake caused the majority of the damage (e.g. the meltdown of the nuclear power plant in Fukushima) and loss of life. Without preparation, the results of the Cascadia tsunami will be similar—widespread devastation in low-lying coastal communities. Luckily, people living in those areas are taking tsunami preparation seriously.

Westport, WA, is town that is built on a spit attached to the mainland by a sandbar less and a mile and a half wide. Because its highest point sits only 28 feet above sea level, tsunami forecasts predict that the town will be overrun by the Cascadia tsunami. Aware of their town’s vulnerability, in April 2013 Westport residents voted for a $13.8 million dollar bond issue to replace an old elementary school in the Ocosta School District with a new structure that will include a gym strong enough to withstand the high-force tsunami surge and tall enough to house 1,000 people out of danger on its roof.[1] This gym is the first publicly funded tsunami shelter in the United States.

Westport is not the only at-risk community when it comes to tsunamis. In Seaside, OR, just south of where the Columbia River meets the Pacific Ocean, sit three of the four Oregon schools located in tsunami hazard zones. Preparing the schools for a tsunami requires moving them to a site 80 feet above sea level with stable soil that will not liquefy if shaken. The Weyerhaeuser forest-products company owned the only suitable land and graciously donated 80 acres to the Seaside School District for the schools’ relocation.[2] The project needs funding to move forward; hence the school district is considering a November bond measure, similar to the one passed in Westport, to build the new schools.

The efforts concerning student safety in these two school districts should serve as an inspiration for communities along the entire Pacific Northwest coast. Project Safe Haven, a community-driven, public project in Washington State, proposed potential locations and designs for more tsunami safety structures like the one in the Ocosta School District. Of course, funding is key for the completion of these projects. As of now local, public-sourced bond measures have been the way that funding is acquired. So, if such a measure comes up on your ballot this November, vote yes. You, or your children, or your children’s children will be thankful for a close-by tsunami refuge when the Cascadia tsunami inevitably hits.

[1] Doughton, Sandi. “Grays Harbor County school to build first U.S. vertical-tsunami refuge.” The Seattle Times 15 October, 2013. Web.

[2] Marx, R.J. “Land gift clears way for new high school.” The Daily Astorian 17 June, 2016. Web.