Washington, IA: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Washington is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Washington in the 19th percentile nationally for seismic hazard - higher than 19% of the 4,875 US cities USGS was checked against here.

Washington by the numbers

USGS's underlying values for Washington: 0.038g peak ground acceleration, 0.08g at short period, 0.064g at 1 second. Within Iowa alone, Washington ranks 13 of 85 cities by seismic hazard - the 86th percentile in-state. Washington has a population of about 7,281.

Bracing and bolting: the actual cost

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 Iowa 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 Iowa.

What this means for insurance

A Washington 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 Washington's figures come from

Washington's Category B 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 B does and doesn't tell you about Washington.