Sinkhole risk in Warren 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: 23%
At or near the surface: 23%
Buried under cover: 0%

What to do about a house in Warren 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 49 of Warren County's 215 square miles on soluble rock, 49 of them with the rock at or near the surface. With about 42,461 residents (198 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 569 map points about 0.6 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 Warren County

The nearest county rated sinkhole country is Winchester city, VA, about 18 miles north, close enough that the same rock may run under the county line. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Rappahannock County, VA 16 mi south · 0% at surface
Winchester city, VA 18 mi north · 90% at surface
Clarke County, VA 18 mi northeast · 74% at surface
Shenandoah County, VA 20 mi west · 50% at surface
Frederick County, VA 21 mi north · 30% at surface
Fauquier County, VA 24 mi southeast · under 1% at surface

Which formation it is

The largest mapped soluble unit here is the Beekmantown Group (dolostone (dolomite)), Ordovician in age, covering about 7% of the county. Next is the Elbrook Formation at 6%.

Against the rest of Virginia

Warren County ranks 43 of 133 in Virginia for soluble rock at the surface, and sits above 76% of US counties on that measure.