Sinkhole risk in Pike 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: 31%
At or near the surface: 31%
Buried under cover: 0%

What to do about a house in Pike 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 206 of Pike County's 672 square miles on soluble rock, 206 of them with the rock at or near the surface. With about 33,124 residents (49 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 287 map points about 1.5 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 Pike County

The nearest county rated sinkhole country is Geneva County, AL, about 49 miles south. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Crenshaw County, AL 23 mi west · 30% at surface
Bullock County, AL 25 mi northeast · 31% at surface
Coffee County, AL 28 mi south · 2% at surface
Barbour County, AL 32 mi east · 14% at surface
Montgomery County, AL 32 mi northwest · 49% at surface
Dale County, AL 32 mi southeast · 7% at surface

Which formation it is

The largest mapped soluble unit here is the Midway Group; Clayton Formation (silt), Paleocene in age, covering about 28% of the county. Next is the Midway Group; Porters Creek Formation at 1%.

Against the rest of Alabama

Pike County ranks 21 of 67 in Alabama for soluble rock at the surface, and sits above 80% of US counties on that measure.