Sinkhole risk in Nelson County, KY: Sinkhole country

Sinkhole country

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

On soluble rock: 56%
At or near the surface: 56%
Buried under cover: under 1%

What this means before you buy

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

That works out to roughly 236 of Nelson County's 419 square miles on soluble rock, 234 of them with the rock at or near the surface. With about 48,706 residents (116 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 447 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Nelson County

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

Washington County, KY 16 mi east · 42% at surface
Bullitt County, KY 17 mi northwest · 42% at surface
Spencer County, KY 17 mi northeast · 56% at surface
Marion County, KY 20 mi southeast · 45% at surface
Larue County, KY 22 mi southwest · 78% at surface
Hardin County, KY 28 mi west · 89% at surface

Which formation it is

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 23% of the county. Next is the Laurel Dolomite, Osgood Formation, and Brassfield Dolomite, undivided at 21%.

Against the rest of Kentucky

Nelson County ranks 35 of 120 in Kentucky for soluble rock at the surface, and sits above 89% of US counties on that measure.