Johnson County, MO Shrink-Swell Risk

Shrink-swell potential in Johnson County, MO

Moderate

Soil across 38.5% of Johnson County, MO comes back "Moderate" in USDA's shrink-swell data, averaging 4.84% 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 Johnson County, MO - 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 Johnson County will actually do.

Johnson County: the real numbers

Johnson 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, Johnson County, MO ranks 323 most-constrained nationally, and 43 of 114 within Missouri. The county spans 829 square miles, home to 55,880 people.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Tulare County, CA and Orange County, TX 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 Missouri

Every county in Missouri is on this site, including Putnam County, MO and Dade County, MO. The full underlying dataset is downloadable directly, one row per county.