Sinkhole risk in Dorchester County, SC: Sinkhole country
Sinkhole country
Soluble rock at or near the surface across much of the county.
- On soluble rock
- 100%
- At or near the surface
- 61%
- Buried under cover
- 39%
What to do about a house in Dorchester County
Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.
That works out to roughly 568 of Dorchester County's 568 square miles on soluble rock, 347 of them with the rock at or near the surface. With about 174,663 residents (307 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 410 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.
Read next: why the 39% under cover still counts, and the signs to look for and how an inspection works.
Counties around Dorchester County
The closest county with no soluble rock mapped is Saluda County, SC, about 99 miles northwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.
- Colleton County, SC 22 mi southwest · 48% at surface
- Berkeley County, SC 27 mi east · 30% at surface
- Charleston County, SC 33 mi southeast · 0% at surface
- Orangeburg County, SC 34 mi northwest · 72% at surface
- Bamberg County, SC 38 mi west · 84% at surface
- Clarendon County, SC 42 mi north · 79% at surface
What Dorchester County is built on
The largest mapped soluble unit here is the Bear Bluff Formation (calcareous sand), Pliocene in age, covering about 33% of the county.
Against the rest of South Carolina
Dorchester County ranks 15 of 46 in South Carolina for soluble rock at the surface, and sits above 90% of US counties on that measure.
- Lee County 88%
- Darlington County 87%
- Bamberg County 84%
- Clarendon County 79%
- Dillon County 79%