Poweshiek County, IA Shrink-Swell Risk

Shrink-swell potential in Poweshiek County, IA

Moderate

Soil across 91.8% of Poweshiek County, IA comes back "Moderate" in USDA's shrink-swell data, averaging 4.65% 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 Poweshiek County, IA - 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).

Poweshiek County: the real numbers

Poweshiek 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, Poweshiek County, IA ranks 358 most-constrained nationally, and 27 of 99 within Iowa. Poweshiek County covers 585 square miles and counts 18,454 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Coshocton County, OH and Allen County, OH 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 Iowa

Every county in Iowa is on this site, including Benton County, IA and Dallas County, IA. The full underlying dataset is downloadable directly, one row per county.