Alexander County, IL Shrink-Swell Risk

Shrink-swell potential in Alexander County, IL

Moderate

Soil across 49.8% of Alexander County, IL comes back "Moderate" in USDA's shrink-swell data, averaging 4.11% 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 Alexander 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 Alexander County will actually do.

Alexander County: the real numbers

Alexander 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.

Alexander County's rank among Illinois counties

Among the 3,085 rated counties on this site, Alexander County, IL ranks 522 most-constrained nationally, and 25 of 101 within Illinois. The county spans 235 square miles, home to 4,594 people.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Rains County, TX and White Pine County, NV 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 Kendall County, IL and Champaign County, IL. The full underlying dataset is downloadable directly, one row per county.