Sinkhole risk in King County, WA: 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 this means before you buy

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

Across 2,116 square miles, under one square mile of King County maps onto soluble rock. With about 2,340,211 residents (1,106 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 288 map points about 2.7 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how these percentages are measured, and the warning signs that apply anywhere.

Counties around King County

The nearest county rated sinkhole country is Emery County, UT, about 808 miles southeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Pierce County, WA 34 mi southwest · 0% at surface
Snohomish County, WA 39 mi north · 0% at surface
Kitsap County, WA 39 mi west · 0% at surface
Kittitas County, WA 60 mi southeast · under 1% at surface
Island County, WA 60 mi northwest · 0% at surface
Thurston County, WA 60 mi southwest · 0% at surface

Against the rest of Washington

King County ranks 24 of 39 in Washington for soluble rock at the surface, and sits above 0% of US counties on that measure.