Sinkhole risk in Pulaski County, AR: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock: 3%
At or near the surface: 3%
Buried under cover: 0%

What this means before you buy

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 24 of Pulaski County's 758 square miles on soluble rock, 24 of them with the rock at or near the surface. With about 401,209 residents (529 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 554 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Pulaski County

The nearest county rated sinkhole country is Izard County, AR, about 94 miles north. None of the 6 closest counties land in the same band, so Pulaski County stands out from its surroundings.

Saline County, AR 22 mi west · 31% at surface
Lonoke County, AR 24 mi east · 0% at surface
Faulkner County, AR 26 mi north · 0% at surface
Grant County, AR 34 mi south · 23% at surface
Perry County, AR 37 mi west · 0% at surface
Conway County, AR 40 mi northwest · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Womble Shale (Middle Ordovician) (shale), Middle Ordovician in age, covering about 3% of the county.

Against the rest of Arkansas

Pulaski County ranks 33 of 75 in Arkansas for soluble rock at the surface, and sits above 60% of US counties on that measure.