Sinkhole risk in Jefferson County, IN: Pockets of it

Pockets of it

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

On soluble rock: 65%
At or near the surface: 16%
Buried under cover: 49%

What to do about a house in Jefferson 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 233 of Jefferson County's 361 square miles on soluble rock, 57 of them with the rock at or near the surface. With about 32,921 residents (91 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 619 map points about 0.8 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 49% under cover still counts, and the signs to look for and how an inspection works.

Counties around Jefferson County

The nearest county rated sinkhole country is Oldham County, KY, about 27 miles south, 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.

Trimble County, KY 12 mi southeast · 16% at surface
Jennings County, IN 18 mi northwest · 7% at surface
Scott County, IN 18 mi southwest · 2% at surface
Carroll County, KY 19 mi southeast · 19% at surface
Switzerland County, IN 22 mi east · 13% at surface
Ripley County, IN 24 mi northeast · 6% at surface

Which formation it is

The largest mapped soluble unit here is the Muscatatuck Group (limestone), Devonian in age, covering about 29% of the county. Next is the Louisville Limestone through Brassfield Limestone at 25%.

Against the rest of Indiana

Jefferson County ranks 11 of 92 in Indiana for soluble rock at the surface, and sits above 72% of US counties on that measure.