Marion County, IA Shrink-Swell Risk

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

Moderate

USDA's SSURGO data puts Marion County, IA's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 5.06% across 73.3% 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 Marion 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 Marion County.

Report cost vs. repair cost

With Marion 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.

How Marion County, IA compares

Nationally, Marion County, IA is the 284-most-constrained of 3,085 rated counties for shrink-swell soil. Within Iowa alone it ranks 17 of 99. The county spans 554 square miles, home to 34,048 people.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Carson City, NV and Lee County, AR 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 Franklin County, IA and Ida County, IA. The full underlying dataset is downloadable directly, one row per county.