Carroll County, IA Shrink-Swell Risk

Shrink-swell potential in Carroll County, IA

Moderate

Soil across 64.4% of Carroll County, IA comes back "Moderate" in USDA's shrink-swell data, averaging 3.55% linear extensibility. 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.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Carroll County, IA - never a reading for one specific parcel. 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 Carroll County.

Carroll County: the real numbers

Carroll County's soil reading points toward standard foundation practice as the likely outcome, not the exception. 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

Among the 3,085 rated counties on this site, Carroll County, IA ranks 808 most-constrained nationally, and 61 of 99 within Iowa. Carroll County covers 569 square miles and counts 20,407 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Wapello County, IA and Roberts County, TX 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

Elsewhere in Iowa

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