SinkholeOdds

Sinkhole risk in Ohio 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
4%
At or near the surface
4%
Buried under cover
0%

What to do about a house in Ohio County

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

That works out to roughly 24 of Ohio County's 587 square miles on soluble rock, 24 of them with the rock at or near the surface. With about 23,933 residents (41 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 566 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Ohio County

The nearest county rated sinkhole country is Grayson County, KY, about 27 miles east, close enough that the same rock may run under the county line. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Which formation it is

The largest mapped soluble unit here is the Rocks of Chesterian age, upper part (shale), Upper Mississippian in age, covering about 3% of the county. Next is the Rocks of Chesterian age, lower part 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

Ohio County ranks 80 of 120 in Kentucky for soluble rock at the surface, and sits above 62% of US counties on that measure.