Sinkhole risk in Cook 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: 16%
Buried under cover: 84%

What to do about a house in Cook 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 228 of Cook County's 228 square miles on soluble rock, 36 of them with the rock at or near the surface. With about 17,984 residents (79 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 245 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Cook County

The nearest county rated sinkhole country is Mitchell County, GA, about 45 miles west. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Berrien County, GA 15 mi northeast · 3% at surface
Colquitt County, GA 20 mi west · 21% at surface
Tift County, GA 22 mi north · 5% at surface
Lanier County, GA 23 mi east · under 1% at surface
Lowndes County, GA 24 mi southeast · 16% at surface
Brooks County, GA 24 mi south · 29% at surface

What Cook County is built on

The largest mapped soluble unit here is the "Hawthorn Formation" (sand), Miocene in age, covering about 84% of the county. Next is the "Hawthorn Formation" at 16%.

The county also lies over the Floridan shelf, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Georgia

Cook County ranks 40 of 159 in Georgia for soluble rock at the surface, and sits above 72% of US counties on that measure.