Sinkhole risk in Scott 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: 9%
At or near the surface: 2%
Buried under cover: 7%

What to do about a house in Scott County

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

That works out to roughly 17 of Scott County's 190 square miles on soluble rock, 3 of them with the rock at or near the surface. With about 24,751 residents (130 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 248 map points about 0.9 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 why the 7% under cover still counts.

Counties around Scott County

The nearest county rated sinkhole country is Washington County, IN, about 20 miles west, close enough that the same rock may run under the county line. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Clark County, IN 14 mi south · 3% at surface
Jefferson County, IN 18 mi northeast · 16% at surface
Washington County, IN 20 mi west · 62% at surface
Trimble County, KY 22 mi east · 16% at surface
Jackson County, IN 22 mi northwest · 2% at surface
Jennings County, IN 23 mi north · 7% at surface

Which formation it is

The largest mapped soluble unit here is the Muscatatuck Group (limestone), Devonian in age, covering about 9% of the county.

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 Indiana

Scott County ranks 25 of 92 in Indiana for soluble rock at the surface, and sits above 57% of US counties on that measure.