Sinkhole risk in Clark County, KY: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 64%
At or near the surface: 64%
Buried under cover: 0%

The next step for one property

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 162 of Clark County's 252 square miles on soluble rock, 162 of them with the rock at or near the surface. With about 37,673 residents (149 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 248 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Clark County

The closest county with no soluble rock mapped is Wolfe County, KY, about 39 miles southeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Montgomery County, KY 14 mi east · 40% at surface
Bourbon County, KY 16 mi north · 89% at surface
Fayette County, KY 18 mi west · 95% at surface
Madison County, KY 18 mi southwest · 46% at surface
Powell County, KY 20 mi southeast · 10% at surface
Estill County, KY 22 mi southeast · 17% at surface

The rock underneath

The largest mapped soluble unit here is the Lexington Limestone (limestone), Ordovician in age, covering about 45% of the county. Next is the Ashlock Formation, Grant Lake and Calloway Creek Limestones, and Fairview Formation, undivided at 12%.

Against the rest of Kentucky

Clark County ranks 25 of 120 in Kentucky for soluble rock at the surface, and sits above 91% of US counties on that measure.