McPherson County, SD Shrink-Swell Risk

What McPherson County, SD's soil means for a foundation

Moderate

USDA's SSURGO data puts McPherson County, SD's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 3.4% across 73.3% of the county's surveyed land. Conventional foundations are the reasonable expectation here, with routine moisture-control practice rather than special engineering.

This is a county figure, not a lot figure

USDA's survey covers the whole of McPherson County, SD at once, not any single address. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in McPherson County will actually do.

Report cost vs. repair cost

With McPherson County, SD rating "Moderate", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. 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

Nationally, McPherson County, SD is the 909-most-constrained of 3,085 rated counties for shrink-swell soil. Within South Dakota alone it ranks 60 of 66. McPherson County covers 1,137 square miles and counts 2,307 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Fallon County, MT and Chester County, TN 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

More of South Dakota

Every county in South Dakota is on this site, including McCook County, SD and Hanson County, SD. The full underlying dataset is downloadable directly, one row per county.