Sinkhole risk in Madison County, KY: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 46%
At or near the surface: 46%
Buried under cover: 0%

What to do about a house in Madison County

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 203 of Madison County's 438 square miles on soluble rock, 203 of them with the rock at or near the surface. With about 99,582 residents (227 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 255 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Madison County

The nearest county rated sinkhole country is Garrard County, KY, about 16 miles southwest, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Garrard County, KY 16 mi southwest · 51% at surface
Estill County, KY 17 mi east · 17% at surface
Clark County, KY 18 mi northeast · 64% at surface
Jessamine County, KY 20 mi northwest · 93% at surface
Fayette County, KY 24 mi northwest · 95% at surface
Powell County, KY 25 mi east · 10% at surface

What Madison County is built on

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 32% of the county. Next is the Crab Orchard Formation and Brassfield Dolomite, undivided at 11%.

Against the rest of Kentucky

Madison County ranks 46 of 120 in Kentucky for soluble rock at the surface, and sits above 86% of US counties on that measure.