St. Clair County, MI Shrink-Swell Risk

Shrink-swell potential in St. Clair County, MI

Low

Soil across 48.9% of St. Clair County, MI comes back "Low" in USDA's shrink-swell data, averaging 2.72% linear extensibility. That's as favorable a county-level reading as this dataset produces - standard foundation practice, pending one lot's own geotechnical report.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in St. Clair County, MI - 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 St. Clair County will actually do.

St. Clair County: the real numbers

St. Clair 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, St. Clair County, MI ranks 1,394 most-constrained nationally, and 3 of 83 within Michigan. The county spans 722 square miles, home to 160,308 people.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Sangamon County, IL and LaGrange County, IN 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 Michigan

Every county in Michigan is on this site, including Newaygo County, MI and Montcalm County, MI. The full underlying dataset is downloadable directly, one row per county.