Guthrie County, IA Shrink-Swell Risk
What Guthrie County, IA's soil means for a foundation
Moderate
USDA's SSURGO data puts Guthrie County, IA's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 4.53% across 71.1% of the county's surveyed land. A real but modest amount of movement - standard foundations usually hold up, but drainage and moisture control around the foundation still matter more than on low-risk soil.
This is a county figure, not a lot figure
USDA's survey covers the whole of Guthrie County, IA at once, not any single address. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in Guthrie County.
Report cost vs. repair cost
With Guthrie 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, Guthrie County, IA is the 380-most-constrained of 3,085 rated counties for shrink-swell soil. Within Iowa alone it ranks 29 of 99. Guthrie County covers 591 square miles and counts 10,774 residents.
Before you act on this
Orleans Parish, LA carries this site's most-constrained reading. Real County, TX and Roanoke County, VA 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 Jackson County, IA and Harrison County, IA. The full underlying dataset is downloadable directly, one row per county.