Sinkhole risk in Dearborn County, IN: 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: 30%
At or near the surface: 10%
Buried under cover: 19%

The next step for one property

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

That works out to roughly 91 of Dearborn County's 305 square miles on soluble rock, 31 of them with the rock at or near the surface. With about 51,435 residents (169 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 283 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 19% under cover still counts, and how these percentages are measured.

Counties around Dearborn County

The nearest county rated sinkhole country is Kenton County, KY, about 28 miles southeast, 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.

Ohio County, IN 14 mi south · 12% at surface
Ripley County, IN 16 mi west · 6% at surface
Boone County, KY 18 mi southeast · 16% at surface
Franklin County, IN 19 mi north · 2% at surface
Switzerland County, IN 22 mi south · 13% at surface
Hamilton County, OH 23 mi east · 2% at surface

What Dearborn County is built on

The largest mapped soluble unit here is the Whitewater Formation (limestone), Ordovician in age, covering about 16% of the county. Next is the Kope Formation at 14%.

Against the rest of Indiana

Dearborn County ranks 15 of 92 in Indiana for soluble rock at the surface, and sits above 68% of US counties on that measure.