Columbia County, OR Shrink-Swell Risk

Shrink-swell potential in Columbia County, OR

Low

Soil across 88.4% of Columbia County, OR comes back "Low" in USDA's shrink-swell data, averaging 1.95% 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 Columbia County, OR - never a reading for one specific parcel. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in Columbia County.

Columbia County: the real numbers

Columbia 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, Columbia County, OR ranks 2,030 most-constrained nationally, and 28 of 36 within Oregon. The county spans 659 square miles, home to 54,063 people.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Liberty County, GA and Solano County, CA 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 Oregon

Every county in Oregon is on this site, including Yamhill County, OR and Curry County, OR. The full underlying dataset is downloadable directly, one row per county.