Sinkhole risk in Bibb County, AL: 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: 12%
At or near the surface: 12%
Buried under cover: 0%

What to do about a house in Bibb County

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

That works out to roughly 72 of Bibb County's 622 square miles on soluble rock, 72 of them with the rock at or near the surface. With about 22,258 residents (36 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 275 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Bibb County

The nearest county rated sinkhole country is Talladega County, AL, about 60 miles northeast. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Chilton County, AL 26 mi southeast · 6% at surface
Perry County, AL 28 mi south · 29% at surface
Tuscaloosa County, AL 30 mi northwest · 2% at surface
Shelby County, AL 32 mi northeast · 30% at surface
Hale County, AL 34 mi southwest · 20% at surface
Jefferson County, AL 39 mi north · 21% at surface

What Bibb County is built on

The largest mapped soluble unit here is the Chepultepec and Copper Ridge Dolomites undifferentiated (dolostone (dolomite)), Ordovician-Cambrian in age, covering about 4% of the county. Next is the Brierfield Dolomite at 2%.

Against the rest of Alabama

Bibb County ranks 38 of 67 in Alabama for soluble rock at the surface, and sits above 69% of US counties on that measure.