Highland's Seismic Design Category, explained

Highland clears the point where the standard Seismic Design Category tables stop applying - USGS returns no letter here, only a flag that a site-specific study (ASCE 7-16 §11.4.8) is required. Treat that as more severe than any lettered category, not as missing data. That puts Highland in the 100th percentile nationally for seismic hazard - higher than 100% of the 4,875 US cities USGS was checked against here.

Highland by the numbers

The raw figures: peak ground acceleration 1.042g, short-period spectral response 2.522g, 1-second spectral response 1g. Among 429 California cities in this dataset, Highland ranks 7 for seismic hazard, the 99th percentile within the state. About 56,499 people live in Highland, California.

What a retrofit costs in Highland

Because Highland is in California, the EBB grant applies if the ZIP code participates and the house qualifies (wood-framed house on a raised (not slab-on-grade) foundation, built before 1980): a $3,000-$7,000 bracing-and-bolting job drops to $0-$4,000 after the $3,000 base grant, or effectively free for income-eligible households getting the full $10,000.

Earthquake insurance for a Highland home

Earthquake coverage in California mostly runs through the California Earthquake Authority (CEA), sold only through licensed agents at CEA-participating insurers - there is no direct-to-consumer CEA policy. A general home-insurance quote is the practical starting point for a Highland homeowner asking about it.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Highland's numbers. The retrofit cost and grant guide covers every EBB eligibility rule, including the ones this page can't check.