Sinkhole risk in Chatham County, GA: 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: 0%
Buried under cover: 12%

What to do about a house in Chatham County

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

That works out to roughly 51 of Chatham County's 433 square miles on soluble rock. With about 307,336 residents (710 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 434 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Chatham County

The nearest county rated sinkhole country is Hampton County, SC, about 55 miles north. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Bryan County, GA 21 mi west · under 1% at surface
Liberty County, GA 25 mi southwest · 0% at surface
Effingham County, GA 30 mi northwest · 18% at surface
Jasper County, SC 31 mi north · 21% at surface
Beaufort County, SC 35 mi northeast · 0% at surface
McIntosh County, GA 38 mi southwest · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Charlton Formation and Duplin Marl (limestone), Pliocene in age, covering about 12% of the county.

Against the rest of Georgia

Chatham County ranks 84 of 159 in Georgia for soluble rock at the surface, and sits above 0% of US counties on that measure.