Wahkiakum County, WA Shrink-Swell Risk

What Wahkiakum County, WA's soil means for a foundation

Low

USDA's SSURGO data puts Wahkiakum County, WA's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 2.15% across 81.1% of the county's surveyed land. Among the 3,144 counties on this site, that's the clean result: little shrink-swell movement, standard construction the likely outcome.

This is a county figure, not a lot figure

USDA's survey covers the whole of Wahkiakum County, WA at once, not any single address. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Wahkiakum County will actually do.

Report cost vs. repair cost

With Wahkiakum County, WA rating "Low", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. 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.

How Wahkiakum County, WA compares

Nationally, Wahkiakum County, WA is the 1,848-most-constrained of 3,085 rated counties for shrink-swell soil. Within Washington alone it ranks 10 of 39. Wahkiakum County, WA is 263 square miles with a population of 4,800.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Jerauld County, SD and Grays Harbor County, WA 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

More of Washington

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