Union County, OR Shrink-Swell Risk

What Union County, OR's soil means for a foundation

Moderate

USDA's SSURGO data puts Union County, OR's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 3.04% across 60.1% of the county's surveyed land. A real but modest amount of movement - standard foundations usually hold up, but drainage and moisture control around the foundation still matter more than on low-risk soil.

This is a county figure, not a lot figure

USDA's survey covers the whole of Union County, OR at once, not any single address. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

Report cost vs. repair cost

With Union County, OR rating "Moderate", 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.

Where this sits nationally

Nationally, Union County, OR is the 1,169-most-constrained of 3,085 rated counties for shrink-swell soil. Within Oregon alone it ranks 15 of 36. Union County covers 2,037 square miles and counts 26,058 residents.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Erie County, PA and Baker County, OR 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 Oregon

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