Sinkhole risk in Irwin 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: 100%
At or near the surface: 0%
Buried under cover: 100%

What to do about a house in Irwin 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 354 of Irwin County's 354 square miles on soluble rock. With about 9,155 residents (26 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 607 map points about 0.8 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Irwin County

The nearest county rated sinkhole country is Crisp County, GA, about 36 miles northwest, close enough that the same rock may run under the county line. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Ben Hill County, GA 11 mi northeast · 0% at surface
Tift County, GA 18 mi southwest · 5% at surface
Turner County, GA 22 mi northwest · 0% at surface
Berrien County, GA 22 mi south · 3% at surface
Coffee County, GA 26 mi east · 0% at surface
Wilcox County, GA 27 mi north · 28% at surface

The rock underneath

The largest mapped soluble unit here is the "Hawthorn Formation" (sand), Miocene in age, covering about 83% of the county. Next is the Suwannee Limestone and its residuum at 17%.

Against the rest of Georgia

Irwin County ranks 112 of 159 in Georgia for soluble rock at the surface, and sits above 0% of US counties on that measure.