Sinkhole risk in Horry County, SC: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 70%
At or near the surface: 29%
Buried under cover: 41%

What this means before you buy

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 788 of Horry County's 1,133 square miles on soluble rock, 323 of them with the rock at or near the surface. With about 413,391 residents (365 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 512 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 41% under cover still counts, and the signs to look for and how an inspection works.

Counties around Horry County

The nearest county rated sinkhole country is Columbus County, NC, about 31 miles northeast, close enough that the same rock may run under the county line. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Marion County, SC 25 mi northwest · 33% at surface
Columbus County, NC 31 mi northeast · 80% at surface
Georgetown County, SC 39 mi southwest · 0% at surface
Dillon County, SC 40 mi northwest · 79% at surface
Florence County, SC 43 mi west · 77% at surface
Brunswick County, NC 44 mi east · 30% at surface

Against the rest of South Carolina

Horry County ranks 23 of 46 in South Carolina for soluble rock at the surface, and sits above 79% of US counties on that measure.