Sinkhole risk in Washington 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: 97%
At or near the surface: 10%
Buried under cover: 87%

What to do about a house in Washington 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 660 of Washington County's 679 square miles on soluble rock, 71 of them with the rock at or near the surface. With about 19,834 residents (29 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 251 map points about 1.6 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 87% under cover still counts, and the signs to look for and how an inspection works.

Counties around Washington County

The nearest county rated sinkhole country is Houston County, GA, about 62 miles southwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Johnson County, GA 21 mi south · 0% at surface
Glascock County, GA 21 mi northeast · 12% at surface
Jefferson County, GA 23 mi east · 8% at surface
Hancock County, GA 24 mi northwest · under 1% at surface
Wilkinson County, GA 25 mi southwest · 44% at surface
Baldwin County, GA 27 mi west · 21% at surface

Which formation it is

The largest mapped soluble unit here is the Lower Tertiary-Cretaceous undifferentiated (sand), Lower Tertiary-Cretaceous in age, covering about 60% of the county. Next is the Cooper Marl at 37%.

Against the rest of Georgia

Washington County ranks 45 of 159 in Georgia for soluble rock at the surface, and sits above 68% of US counties on that measure.