Bay City, MI: what USGS's seismic model says

Bay City carries Seismic Design Category A under USGS's ASCE 7-16 model. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Nationally, Bay City ranks above 11% of the 4,875 cities in this dataset for seismic hazard - the 11th percentile.

Bay City by the numbers

USGS's underlying values for Bay City: 0.031g peak ground acceleration, 0.066g at short period, 0.039g at 1 second. Within Michigan alone, Bay City ranks 136 of 153 cities by seismic hazard - the 11th percentile in-state. Bay City has a population of about 32,086.

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 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.

What this means for insurance

A Bay 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 Bay City's figures come from

Bay City's Category A 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 A does and doesn't tell you about Bay City.