Gig Harbor, WA: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Gig Harbor is Category D. 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. Nationally, Gig Harbor ranks above 94% of the 4,875 cities in this dataset for seismic hazard - the 94th percentile.

Gig Harbor by the numbers

USGS's underlying values for Gig Harbor: 0.632g peak ground acceleration, 1.49g at short period, 0.52g at 1 second. Within Washington alone, Gig Harbor ranks 11 of 125 cities by seismic hazard - the 92th percentile in-state. Gig Harbor has a population of about 12,643.

Retrofit economics for Gig Harbor

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 Gig Harbor 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 Gig Harbor's figures come from

Gig Harbor'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 Gig Harbor.