Springfield, IL: what USGS's seismic model says

Springfield carries Seismic Design Category C under USGS's ASCE 7-16 model. Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. Nationally, Springfield ranks above 69% of the 4,875 cities in this dataset for seismic hazard - the 69th percentile.

Springfield by the numbers

USGS's underlying values for Springfield: 0.095g peak ground acceleration, 0.194g at short period, 0.101g at 1 second. Within Illinois alone, Springfield ranks 55 of 330 cities by seismic hazard - the 84th percentile in-state. Springfield has a population of about 112,949.

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 Illinois 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 Illinois.

Earthquake insurance for a Springfield home

A Springfield 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 Springfield's figures come from

Springfield's Category C 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 C does and doesn't tell you about Springfield.