Sinkhole risk in Henry County, AL: Pockets of it

Pockets of it

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

On soluble rock: 20%
At or near the surface: 20%
Buried under cover: 0%

What this means before you buy

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 112 of Henry County's 562 square miles on soluble rock, 112 of them with the rock at or near the surface. With about 18,141 residents (32 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 322 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Henry County

The nearest county rated sinkhole country is Early County, GA, about 24 miles southeast, close enough that the same rock may run under the county line. None of the 6 closest counties land in the same band, so Henry County stands out from its surroundings.

Clay County, GA 16 mi northeast · 1% at surface
Dale County, AL 23 mi west · 7% at surface
Early County, GA 24 mi southeast · 81% at surface
Houston County, AL 25 mi south · 84% at surface
Barbour County, AL 26 mi north · 14% at surface
Quitman County, GA 28 mi northeast · under 1% at surface

What Henry County is built on

The largest mapped soluble unit here is the Claiborne/Jackson Group; Residuum (residuum), Eocene-Oligocene in age, covering about 19% of the county. Next is the Midway Group; Clayton Formation at under 1%.

Against the rest of Alabama

Henry County ranks 33 of 67 in Alabama for soluble rock at the surface, and sits above 74% of US counties on that measure.