Sinkhole risk in Roanoke County, VA: Pockets of it

Pockets of it

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

On soluble rock: 33%
At or near the surface: 33%
Buried under cover: 0%

The next step for one property

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 83 of Roanoke County's 251 square miles on soluble rock, 83 of them with the rock at or near the surface. With about 97,334 residents (388 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 539 map points about 0.7 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Roanoke County

The nearest county rated sinkhole country is Salem city, VA, about 8 miles southeast, 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.

Salem city, VA 8 mi southeast · 100% at surface
Craig County, VA 10 mi north · 34% at surface
Roanoke city, VA 13 mi east · 98% at surface
Montgomery County, VA 15 mi southwest · 64% at surface
Radford city, VA 25 mi southwest · 84% at surface
Monroe County, WV 25 mi northwest · 69% at surface

What Roanoke County is built on

The largest mapped soluble unit here is the Rome Formation (shale), Cambrian in age, covering about 11% of the county. Next is the Moccasin or Bays Formation through Blackford Formation at 6%.

Against the rest of Virginia

Roanoke County ranks 36 of 133 in Virginia for soluble rock at the surface, and sits above 81% of US counties on that measure.