Iowa City, IA: what USGS's seismic model says

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

Where Iowa City sits in Iowa

USGS's underlying values for Iowa City: 0.036g peak ground acceleration, 0.076g at short period, 0.06g at 1 second. Within Iowa alone, Iowa City ranks 16 of 85 cities by seismic hazard - the 82th percentile in-state. Iowa City has a population of about 76,710.

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 Iowa City 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 Iowa City's figures come from

Iowa City'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 Iowa City.