Thatcher's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Thatcher is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Thatcher sits at the 58th percentile for seismic hazard among 4,875 US cities.

How Thatcher compares

USGS's underlying values for Thatcher: 0.112g peak ground acceleration, 0.254g at short period, 0.081g at 1 second. Within Arizona alone, Thatcher ranks 26 of 57 cities by seismic hazard - the 55th percentile in-state. Thatcher has a population of about 5,627.

What a retrofit costs in Thatcher

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 Arizona 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 Arizona.

Earthquake insurance for a Thatcher home

A Thatcher 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 Thatcher's figures come from

Thatcher'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 Thatcher.