Sammamish, WA: what USGS's seismic model says

Sammamish carries Seismic Design Category D under USGS's ASCE 7-16 model. High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. Rank it against the rest of the country and Sammamish sits at the 92th percentile for seismic hazard among 4,875 US cities.

How Sammamish compares

USGS's underlying values for Sammamish: 0.553g peak ground acceleration, 1.286g at short period, 0.449g at 1 second. Within Washington alone, Sammamish ranks 32 of 125 cities by seismic hazard - the 75th percentile in-state. Sammamish has a population of about 66,474.

Retrofit economics for Sammamish

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Washington specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Washington.

Insuring against this, not just retrofitting

A Sammamish homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Sammamish's figures come from

Sammamish's Category D and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category D does and doesn't tell you about Sammamish.