McDonough County, IL Shrink-Swell Risk

Shrink-swell potential in McDonough County, IL

Moderate

Soil across 86.3% of McDonough County, IL comes back "Moderate" in USDA's shrink-swell data, averaging 4.22% 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 McDonough County, IL - never a reading for one specific parcel. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

McDonough County: the real numbers

McDonough 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.

McDonough County's rank among Illinois counties

Among the 3,085 rated counties on this site, McDonough County, IL ranks 463 most-constrained nationally, and 19 of 101 within Illinois. McDonough County covers 589 square miles and counts 26,662 residents.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Madison County, NE and Somerset County, ME 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 Greene County, IL and Cass County, IL. The full underlying dataset is downloadable directly, one row per county.