Does Broken Arrow, OK need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Broken Arrow in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Broken Arrow in the 41th percentile nationally for seismic hazard - higher than 41% of the 4,875 US cities USGS was checked against here.

Where Broken Arrow sits in Oklahoma

The raw figures: peak ground acceleration 0.064g, short-period spectral response 0.133g, 1-second spectral response 0.072g. Among 75 Oklahoma cities in this dataset, Broken Arrow ranks 60 for seismic hazard, the 20th percentile within the state. About 122,756 people live in Broken Arrow, Oklahoma.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Oklahoma. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Broken Arrow address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Broken Arrow's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.