Sinkhole risk in Pender County, NC: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 89%
At or near the surface: 89%
Buried under cover: 0%

The next step for one property

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 776 of Pender County's 871 square miles on soluble rock, 776 of them with the rock at or near the surface. With about 70,077 residents (80 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 276 map points about 1.8 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Pender County

The closest county with no soluble rock mapped is Franklin County, NC, about 111 miles north. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

New Hanover County, NC 23 mi south · 79% at surface
Onslow County, NC 28 mi northeast · 65% at surface
Duplin County, NC 29 mi north · 93% at surface
Bladen County, NC 37 mi west · 38% at surface
Brunswick County, NC 38 mi southwest · 30% at surface
Sampson County, NC 43 mi northwest · 77% at surface

The rock underneath

The largest mapped soluble unit here is the Peedee Formation (sand), Cretaceous in age, covering about 60% of the county. Next is the Castle Hayne Formation; Comfort Member and New Hanover Member, undivided at 24%.

Against the rest of North Carolina

Pender County ranks 4 of 100 in North Carolina for soluble rock at the surface, and sits above 97% of US counties on that measure.