Sinkhole risk in Shelby County, KY: Sinkhole country

Sinkhole country

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

On soluble rock: 68%
At or near the surface: 68%
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 257 of Shelby County's 380 square miles on soluble rock, 257 of them with the rock at or near the surface. With about 50,124 residents (132 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 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Shelby County

The closest county with no soluble rock mapped is Brown County, IN, about 85 miles northwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Spencer County, KY 16 mi south · 56% at surface
Henry County, KY 16 mi north · 48% at surface
Oldham County, KY 17 mi northwest · 88% at surface
Franklin County, KY 20 mi east · 47% at surface
Anderson County, KY 21 mi southeast · 25% at surface
Jefferson County, KY 24 mi west · 59% at surface

The rock underneath

The largest mapped soluble unit here is the Ashlock Formation, Grant Lake and Calloway Creek Limestones, and Fairview Formation, undivided (limestone), Ordovician in age, covering about 56% of the county. Next is the Drakes Formation at 11%.

Against the rest of Kentucky

Shelby County ranks 22 of 120 in Kentucky for soluble rock at the surface, and sits above 92% of US counties on that measure.