Sinkhole risk in Charleston County, SC: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock: 29%
At or near the surface: 0%
Buried under cover: 29%

What to do about a house in Charleston County

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 270 of Charleston County's 918 square miles on soluble rock. With about 431,001 residents (469 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 316 map points about 1.7 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Charleston County

The nearest county rated sinkhole country is Dorchester County, SC, about 33 miles northwest, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Berkeley County, SC 28 mi north · 30% at surface
Dorchester County, SC 33 mi northwest · 61% at surface
Colleton County, SC 42 mi west · 48% at surface
Beaufort County, SC 53 mi southwest · 0% at surface
Georgetown County, SC 57 mi northeast · 0% at surface
Williamsburg County, SC 59 mi north · 31% at surface

Against the rest of South Carolina

Charleston County ranks 36 of 46 in South Carolina for soluble rock at the surface, and sits above 0% of US counties on that measure.