Navajo County, AZ Shrink-Swell Risk

What Navajo County, AZ's soil means for a foundation

Low

USDA's SSURGO data puts Navajo County, AZ's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 2.75% across 61.3% of the county's surveyed land. That's the easiest starting point on this site's scale - a standard foundation is the reasonable default here, though any one lot can still differ.

This is a county figure, not a lot figure

USDA's survey covers the whole of Navajo County, AZ at once, not any single address. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Navajo County will actually do.

Report cost vs. repair cost

With Navajo County, AZ rating "Low", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. A geotechnical report runs $1,000-$5,000, typically around $2,700. Foundation repair, if a specific lot turns out to differ from the county average, runs $5,000-$15,000.

Where this sits nationally

Nationally, Navajo County, AZ is the 1,373-most-constrained of 3,085 rated counties for shrink-swell soil. Within Arizona alone it ranks 8 of 15. The county spans 9,949 square miles, home to 109,516 people.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Sierra County, CA and St. Clair County, IL are worth a look for comparison.

How this reading is built, and its real limits · Moisture management: the cheap fix that works on any soil

More of Arizona

Every county in Arizona is on this site, including Yuma County, AZ and Santa Cruz County, AZ. The full underlying dataset is downloadable directly, one row per county.