Sinkhole risk in Washington County, OR: No soluble rock mapped

No soluble rock mapped

No soluble bedrock mapped.

On soluble rock: 0%
At or near the surface: 0%
Buried under cover: 0%

What to do about a house in Washington County

No soluble bedrock is mapped here, so natural sinkholes are unlikely. Collapses from broken pipes or old mines are a separate risk.

Across 724 square miles, under one square mile of Washington County maps onto soluble rock. With about 611,272 residents (844 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 244 map points about 1.7 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Washington County

The nearest county rated sinkhole country is Emery County, UT, about 776 miles southeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Yamhill County, OR 24 mi southwest · 0% at surface
Columbia County, OR 27 mi north · 0% at surface
Tillamook County, OR 33 mi west · 0% at surface
Multnomah County, OR 33 mi east · 0% at surface
Clark County, WA 33 mi northeast · 0% at surface
Clatsop County, OR 44 mi northwest · 0% at surface

Against the rest of Oregon

Washington County ranks 34 of 36 in Oregon for soluble rock at the surface, and sits above 0% of US counties on that measure.