Centerville, IA: what USGS's seismic model says

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Centerville in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Centerville sits at the 19th percentile for seismic hazard among 4,875 US cities.

How Centerville compares

The raw figures: peak ground acceleration 0.037g, short-period spectral response 0.08g, 1-second spectral response 0.066g. Among 85 Iowa cities in this dataset, Centerville ranks 15 for seismic hazard, the 83th percentile within the state. About 5,345 people live in Centerville, Iowa.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Iowa. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

Earthquake insurance for a Centerville home

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Centerville address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Centerville's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.