De Witt County, IL Shrink-Swell Risk
Shrink-swell potential in De Witt County, IL
Moderate
Soil across 92.9% of De Witt County, IL comes back "Moderate" in USDA's shrink-swell data, averaging 4.31% 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 De Witt 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 De Witt County will actually do.
De Witt County: the real numbers
De Witt 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.
How De Witt County, IL compares
Among the 3,085 rated counties on this site, De Witt County, IL ranks 437 most-constrained nationally, and 13 of 101 within Illinois. De Witt County, IL is 398 square miles with a population of 15,319.
Before you act on this
Orleans Parish, LA carries this site's most-constrained reading. Mills County, TX and Grand County, CO 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 Monroe County, IL and Franklin County, IL. The full underlying dataset is downloadable directly, one row per county.