Clay County, SD Shrink-Swell Risk

Clay County, SD's soil, for shrink-swell risk

Moderate

Clay County, SD: USDA's soil survey rates 70.3% of the county "Moderate" for shrink-swell potential (5.05% 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 Clay County's reading doesn't cover

Two lots a mile apart in Clay County can carry different soil, even though they share one countywide reading. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Clay County will actually do.

What it costs to find out, versus to ignore it

With Clay 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.

How Clay County, SD compares

Nationally, Clay County, SD is the 287-most-constrained of 3,085 rated counties for shrink-swell soil. Within South Dakota alone it ranks 19 of 66. Clay County, SD is 412 square miles with a population of 15,245.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Scott County, IA and St. Mary's County, MD 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 Bon Homme County, SD and Perkins County, SD. The full underlying dataset is downloadable directly, one row per county.