Sinkhole risk in Canyon County, ID: Not karst, but voids possible

Not karst, but voids possible

No soluble bedrock; some pseudokarst (piping or lava-tube ground).

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

The next step for one property

Not true karst, but soil piping or lava tubes can still open voids - mention it to an inspector.

Across 587 square miles, under one square mile of Canyon County maps onto soluble rock. With about 266,892 residents (455 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 562 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how ground with no limestone still opens up, and how these percentages are measured.

Counties around Canyon County

The nearest county rated sinkhole country is Emery County, UT, about 445 miles southeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Payette County, ID 26 mi north · 0% at surface
Ada County, ID 26 mi southeast · 0% at surface
Gem County, ID 34 mi northeast · 0% at surface
Malheur County, OR 54 mi southwest · under 1% at surface
Boise County, ID 55 mi northeast · 0% at surface
Washington County, ID 57 mi north · 0% at surface

Against the rest of Idaho

Canyon County ranks 31 of 44 in Idaho for soluble rock at the surface, and sits above 0% of US counties on that measure.