Perkins County, SD Shrink-Swell Risk

Shrink-swell potential in Perkins County, SD

Moderate

Soil across 47.8% of Perkins County, SD comes back "Moderate" in USDA's shrink-swell data, averaging 3.3% linear extensibility. 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.

What this number does and doesn't tell you

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

Perkins County: the real numbers

Perkins 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, Perkins County, SD ranks 979 most-constrained nationally, and 61 of 66 within South Dakota. Perkins County, SD is 2,870 square miles with a population of 2,832.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Stanton County, KS and Van Buren County, MI 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 South Dakota

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