Stephenson County, IL Shrink-Swell Risk

Stephenson County, IL's soil, for shrink-swell risk

Moderate

Stephenson County, IL: USDA's soil survey rates 83.7% of the county "Moderate" for shrink-swell potential (3.74% 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 Stephenson County's reading doesn't cover

Two lots a mile apart in Stephenson County can carry different soil, even though they share one countywide reading. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Stephenson County will actually do.

What it costs to find out, versus to ignore it

With Stephenson County, IL 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, Stephenson County, IL is the 704-most-constrained of 3,085 rated counties for shrink-swell soil. Within Illinois alone it ranks 42 of 101. The county spans 564 square miles, home to 43,088 people.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Glacier County, MT and Thayer County, NE 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 Illinois

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