Pennington County, SD Shrink-Swell Risk

Shrink-swell potential in Pennington County, SD

Moderate

Soil across 42.9% of Pennington County, SD comes back "Moderate" in USDA's shrink-swell data, averaging 4.44% 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 Pennington County, SD - never a reading for one specific parcel. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

Pennington County: the real numbers

Pennington 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.

How Pennington County, SD compares

Among the 3,085 rated counties on this site, Pennington County, SD ranks 399 most-constrained nationally, and 26 of 66 within South Dakota. Pennington County, SD is 2,777 square miles with a population of 115,979.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Warren County, IN and Dawson County, GA 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 Faulk County, SD and Lyman County, SD. The full underlying dataset is downloadable directly, one row per county.