Hamilton County, IL Shrink-Swell Risk

Shrink-swell potential in Hamilton County, IL

Moderate

Soil across 48.5% of Hamilton County, IL comes back "Moderate" in USDA's shrink-swell data, averaging 3.09% linear extensibility. That's a middle reading: not the sharp swings that crack a foundation outright, but enough that grading and drainage are worth getting right.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Hamilton County, IL - never a reading for one specific parcel. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Hamilton County will actually do.

Hamilton County: the real numbers

Hamilton 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, Hamilton County, IL ranks 1,129 most-constrained nationally, and 86 of 101 within Illinois. Hamilton County covers 435 square miles and counts 7,818 residents.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Fillmore County, NE and Monroe County, WV 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 Illinois

Every county in Illinois is on this site, including Douglas County, IL and Fayette County, IL. The full underlying dataset is downloadable directly, one row per county.