Lyon County, IA Shrink-Swell Risk

What Lyon County, IA's soil means for a foundation

Moderate

USDA's SSURGO data puts Lyon County, IA's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 4.22% across 89.5% of the county's surveyed land. Conventional foundations are the reasonable expectation here, with routine moisture-control practice rather than special engineering.

This is a county figure, not a lot figure

USDA's survey covers the whole of Lyon County, IA at once, not any single address. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

Report cost vs. repair cost

With Lyon County, IA rating "Moderate", 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, Lyon County, IA is the 465-most-constrained of 3,085 rated counties for shrink-swell soil. Within Iowa alone it ranks 35 of 99. Lyon County, IA is 588 square miles with a population of 12,378.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Gray County, KS and Peach County, GA 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 Iowa

Every county in Iowa is on this site, including Wayne County, IA and Cerro Gordo County, IA. The full underlying dataset is downloadable directly, one row per county.