Grantsville's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Grantsville in Seismic Design Category D: High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. Rank it against the rest of the country and Grantsville sits at the 84th percentile for seismic hazard among 4,875 US cities.

Grantsville by the numbers

USGS's underlying values for Grantsville: 0.263g peak ground acceleration, 0.606g at short period, 0.219g at 1 second. Within Utah alone, Grantsville ranks 83 of 95 cities by seismic hazard - the 13th percentile in-state. Grantsville has a population of about 15,682.

Retrofit economics for Grantsville

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 Utah 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 Utah.

What this means for insurance

A Grantsville 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 Grantsville's figures come from

Grantsville's Category D 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 D does and doesn't tell you about Grantsville.