Linn County, IA Shrink-Swell Risk

Shrink-swell potential in Linn County, IA

Low

Soil across 57% of Linn County, IA comes back "Low" in USDA's shrink-swell data, averaging 2.78% linear extensibility. That's the easiest starting point on this site's scale - a standard foundation is the reasonable default here, though any one lot can still differ.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Linn 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).

Linn County: the real numbers

Linn 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, Linn County, IA ranks 1,356 most-constrained nationally, and 98 of 99 within Iowa. Linn County covers 717 square miles and counts 231,762 residents.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Holmes County, OH and Stephenson County, IL 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 Jefferson County, IA and Jones County, IA. The full underlying dataset is downloadable directly, one row per county.