Sinkhole risk in Ada 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 1,052 square miles, under one square mile of Ada County maps onto soluble rock. With about 535,799 residents (509 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 334 map points about 1.8 miles apart, so a pocket smaller than that can be missed or overstated.
Read next: how ground with no limestone still opens up, and how these percentages are measured.
Counties around Ada County
The nearest county rated sinkhole country is Emery County, UT, about 420 miles southeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.
- Canyon County, ID 26 mi northwest · 0% at surface
- Elmore County, ID 39 mi east · 0% at surface
- Gem County, ID 43 mi north · 0% at surface
- Boise County, ID 45 mi northeast · 0% at surface
- Payette County, ID 46 mi northwest · 0% at surface
- Owyhee County, ID 61 mi south · 0% at surface
Against the rest of Idaho
Ada County ranks 27 of 44 in Idaho for soluble rock at the surface, and sits above 0% of US counties on that measure.
- Bear Lake County 45%
- Oneida County 44%
- Franklin County 37%
- Bannock County 29%
- Caribou County 24%