Montgomery County, IA Shrink-Swell Risk

Shrink-swell potential in Montgomery County, IA

Moderate

Soil across 87.4% of Montgomery County, IA comes back "Moderate" in USDA's shrink-swell data, averaging 4.58% 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 this number does and doesn't tell you

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

Montgomery County: the real numbers

Montgomery 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, Montgomery County, IA ranks 374 most-constrained nationally, and 28 of 99 within Iowa. Montgomery County, IA is 424 square miles with a population of 10,063.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Leelanau County, MI and Howard County, AR 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 Crawford County, IA and Mahaska County, IA. The full underlying dataset is downloadable directly, one row per county.