Chaska's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Chaska is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Nationally, Chaska ranks above 6% of the 4,875 cities in this dataset for seismic hazard - the 6th percentile.

How Chaska compares

USGS's underlying values for Chaska: 0.023g peak ground acceleration, 0.049g at short period, 0.03g at 1 second. Within Minnesota alone, Chaska ranks 56 of 155 cities by seismic hazard - the 64th percentile in-state. Chaska has a population of about 30,167.

What a retrofit costs in Chaska

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 Minnesota 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 Minnesota.

Insuring against this, not just retrofitting

A Chaska 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 Chaska's figures come from

Chaska'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 Chaska.