Does St. Johns, MI need an earthquake retrofit?

St. Johns carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, St. Johns ranks above 21% of the 4,875 cities in this dataset for seismic hazard - the 21th percentile.

How St. Johns compares

USGS's underlying values for St. Johns: 0.04g peak ground acceleration, 0.082g at short period, 0.044g at 1 second. Within Michigan alone, St. Johns ranks 111 of 153 cities by seismic hazard - the 28th percentile in-state. St. Johns has a population of about 7,723.

Retrofit economics for St. Johns

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 Michigan 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 Michigan.

Earthquake insurance for a St. Johns home

A St. Johns 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 St. Johns's figures come from

St. Johns'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 St. Johns.