Sinkhole risk in Hancock County, KY: 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: 7%
At or near the surface: 6%
Buried under cover: 1%

What to do about a house in Hancock County

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

That works out to roughly 12 of Hancock County's 188 square miles on soluble rock, 10 of them with the rock at or near the surface. With about 9,013 residents (48 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 439 map points about 0.7 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Hancock County

The nearest county rated sinkhole country is Breckinridge County, KY, about 20 miles east, 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.

Spencer County, IN 17 mi northwest · under 1% at surface
Daviess County, KY 18 mi southwest · 0% at surface
Perry County, IN 19 mi northeast · 49% at surface
Breckinridge County, KY 20 mi east · 89% at surface
Ohio County, KY 25 mi south · 4% at surface
Warrick County, IN 31 mi northwest · 0% at surface

What Hancock County is built on

The largest mapped soluble unit here is the Rocks of Chesterian age, upper part (shale), Upper Mississippian in age, covering about 6% of the county. Next is the Buffalo Wallow Group at under 1%.

The county also lies over the Illinois Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Kentucky

Hancock County ranks 79 of 120 in Kentucky for soluble rock at the surface, and sits above 63% of US counties on that measure.