Sinkhole risk in Echols 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: 7%
Buried under cover: 93%

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 420 of Echols County's 420 square miles on soluble rock, 29 of them with the rock at or near the surface. With about 3,698 residents (9 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 265 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and why the 93% under cover still counts.

Counties around Echols County

The nearest county rated sinkhole country is Hamilton County, FL, about 15 miles south, close enough that the same rock may run under the county line. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Hamilton County, FL 15 mi south · 88% at surface
Clinch County, GA 18 mi northeast · 0% at surface
Lowndes County, GA 24 mi west · 16% at surface
Lanier County, GA 24 mi northwest · under 1% at surface
Ware County, GA 37 mi northeast · 0% at surface
Suwannee County, FL 37 mi south · 40% at surface

What Echols County is built on

The largest mapped soluble unit here is the "Hawthorn Formation" (sand), Miocene in age, covering about 93% of the county. Next is the "Hawthorn Formation" at 6%.

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

Echols County ranks 50 of 159 in Georgia for soluble rock at the surface, and sits above 65% of US counties on that measure.