Hannah Cleverley: tsunami modeling shows high casualty risk; county presses for local preparedness

Hannah Cleverley, deputy director of emergency management for Grays Harbor County, told a Cosmopolis workshop that hazard mapping and modeling presented to county officials show severe potential impacts from a Cascadia subduction-zone earthquake and ensuing tsunami and that local preparedness work must accelerate.

Cleverley said the Washington Geological Survey’s mapping and modeling — briefed to local officials in April — estimated more than $20 million in infrastructure loss in Grays Harbor County in a worst-case scenario and described model outputs that project very large casualty numbers in some inundation zones. "They estimated, for our county, between 46 to 54 percent of the population could have casualties in the most severe scenarios," Cleverley said, adding that the study counts deaths and injuries together as 'casualties.'

Why this matters: Cosmopolis and other small coastal jurisdictions face geography and funding constraints that limit options for horizontal evacuation. Cleverley used the briefing to underscore the county’s outreach needs — clearer signage, more public education, and investment in vertical-evacuation options where terrain requires them.

Cleverley walked workshop attendees through recent local events that shaped emergency planning: a February jail fire in Grays Harbor County that required evacuation of 107 inmates and a December dam emergency at Lake Sylvia that contributed to countywide flooding. She said the December storms have produced statewide damage estimates exceeding $187,000,000 and that county agencies alone recorded roughly $1,000,000 in damages; a request for a federal major disaster declaration was expected to be submitted to the president.

On the casualty figures, Cleverley answered a follow-up question about whether the '60 percent' figure referred to mortality or to population impact. She said the modelers used daytime and tourist populations for some scenarios but relied primarily on residential data; the report gives scenario-by-scenario casualty counts, she said, including roughly 29,506 casualties at a 10-minute evacuation-departure assumption and about 31,000 at a 15-minute departure assumption, with higher totals for longer delays. "When they talk about casualties, they're talking about deaths and injuries collectively," she said.

Cleverley said the county will continue to use the new 'undetermined' tsunami advisory category while agencies assess potential threats after offshore earthquakes and that the county holds hourly coordination calls while assessing advisories. She also highlighted recent public-outreach work — an annual preparedness expo (estimated 400 attendees and 40 vendors), quarterly emergency operations center exercises, and an April tsunami-hazard briefing — and offered to share the underlying data and links to the Washington Emergency Management Division report by email. "If you want that data, email me and I can send that out," she told attendees.

Among practical local steps discussed, Cleverley described a prior county GPS inventory of tsunami signage and said Washington state officials have developed higher-visibility orange 'entering tsunami zone' markers to replace older blue-and-white signs that blend into coastal scenery. She encouraged local officials to work with public works on placement and said the county and Corps of Engineers have provided pallets of sandbags to agencies for flood response.

Cleverley also introduced Andrea Wingo as the county’s new emergency management program manager and said the county’s priorities for 2026 include continuity-of-operations and continuity-of-government plans, expanded outreach and volunteer recruitment for ham radio and search-and-rescue teams.

The workshop closed with an offer to support local preparedness events and to provide printed checklists and outreach materials for Cosmopolis’ community center and utility bill mailings. Cleverley directed attendees to the Washington Emergency Management Division website for the briefing and said she would share data on request.