Sioux County, ND Shrink-Swell Risk

What Sioux County, ND's soil means for a foundation

Moderate

USDA's SSURGO data puts Sioux County, ND's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 3.27% across 57% of the county's surveyed land. A real but modest amount of movement - standard foundations usually hold up, but drainage and moisture control around the foundation still matter more than on low-risk soil.

This is a county figure, not a lot figure

USDA's survey covers the whole of Sioux County, ND 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 Sioux County will actually do.

Report cost vs. repair cost

With Sioux County, ND 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, Sioux County, ND is the 1,001-most-constrained of 3,085 rated counties for shrink-swell soil. Within North Dakota alone it ranks 16 of 53. Sioux County, ND is 1,094 square miles with a population of 3,713.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Wythe County, VA and Costilla County, CO 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 North Dakota

Every county in North Dakota is on this site, including Hettinger County, ND and Rolette County, ND. The full underlying dataset is downloadable directly, one row per county.