Sinkhole risk in Bryan County, GA: Pockets of it

Pockets of it

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

On soluble rock: 52%
At or near the surface: under 1%
Buried under cover: 51%

The next step for one property

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 227 of Bryan County's 438 square miles on soluble rock, 4 of them with the rock at or near the surface. With about 51,105 residents (117 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 347 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Bryan County

The nearest county rated sinkhole country is Hampton County, SC, about 55 miles north. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Liberty County, GA 15 mi south · 0% at surface
Chatham County, GA 21 mi east · 0% at surface
Effingham County, GA 24 mi north · 18% at surface
Long County, GA 26 mi southwest · 0% at surface
Evans County, GA 28 mi west · 0% at surface
Bulloch County, GA 31 mi northwest · 13% at surface

Which formation it is

The largest mapped soluble unit here is the Charlton Formation and Duplin Marl (limestone), Pliocene in age, covering about 47% of the county. Next is the "Hawthorn Formation" at 4%.

Against the rest of Georgia

Bryan County ranks 65 of 159 in Georgia for soluble rock at the surface, and sits above 55% of US counties on that measure.