Sinkhole risk in Shenandoah 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: 50%
At or near the surface: 50%
Buried under cover: 0%

What to do about a house in Shenandoah County

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 252 of Shenandoah County's 508 square miles on soluble rock, 252 of them with the rock at or near the surface. With about 45,441 residents (89 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 496 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Shenandoah County

The nearest county rated sinkhole country is Winchester city, VA, about 31 miles northeast, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Page County, VA 17 mi south · 37% at surface
Hardy County, WV 18 mi northwest · 10% at surface
Warren County, VA 20 mi east · 23% at surface
Rappahannock County, VA 25 mi southeast · 0% at surface
Frederick County, VA 29 mi northeast · 30% at surface
Rockingham County, VA 29 mi southwest · 45% at surface

The rock underneath

The largest mapped soluble unit here is the Beekmantown Group (dolostone (dolomite)), Ordovician in age, covering about 19% of the county. Next is the Ridgeley Sandstone, Helderberg and Cayugan Groups at 11%.

Against the rest of Virginia

Shenandoah County ranks 22 of 133 in Virginia for soluble rock at the surface, and sits above 87% of US counties on that measure.