Skamania County, WA Shrink-Swell Risk

Shrink-swell potential in Skamania County, WA

Low

Soil across 83.4% of Skamania County, WA comes back "Low" in USDA's shrink-swell data, averaging 2.07% 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 Skamania County, WA - 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).

Skamania County: the real numbers

Skamania 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, Skamania County, WA ranks 1,916 most-constrained nationally, and 12 of 39 within Washington. The county spans 1,658 square miles, home to 12,660 people.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Lewis County, ID and Wilson County, NC 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 Washington

Every county in Washington is on this site, including Whatcom County, WA and Wahkiakum County, WA. The full underlying dataset is downloadable directly, one row per county.