Mackinac County, MI Shrink-Swell Risk

Shrink-swell potential in Mackinac County, MI

Low

Soil across 94.3% of Mackinac County, MI comes back "Low" in USDA's shrink-swell data, averaging 0.75% 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 Mackinac County, MI - never a reading for one specific parcel. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in Mackinac County.

Mackinac County: the real numbers

Mackinac 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.

Mackinac County's rank among Michigan counties

Among the 3,085 rated counties on this site, Mackinac County, MI ranks 3,007 most-constrained nationally, and 72 of 83 within Michigan. Mackinac County covers 1,022 square miles and counts 11,144 residents.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Bailey County, TX and Winchester city, VA 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 Oceana County, MI and Houghton County, MI. The full underlying dataset is downloadable directly, one row per county.