Sinkhole risk in Radford city, VA: Sinkhole country

Sinkhole country

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

On soluble rock: 84%
At or near the surface: 84%
Buried under cover: 0%

What to do about a house in Radford city

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

That works out to roughly 8 of Radford city's 10 square miles on soluble rock, 8 of them with the rock at or near the surface. With about 17,273 residents (1,785 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 531 map points about 0.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Radford city

The closest county with no soluble rock mapped is Floyd County, VA, about 17 miles southeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Pulaski County, VA 9 mi southwest · 57% at surface
Montgomery County, VA 10 mi east · 64% at surface
Giles County, VA 16 mi northwest · 65% at surface
Floyd County, VA 17 mi southeast · under 1% at surface
Roanoke County, VA 25 mi northeast · 33% at surface
Carroll County, VA 28 mi south · under 1% at surface

Which formation it is

The largest mapped soluble unit here is the Elbrook Formation (dolostone (dolomite)), Cambrian in age, covering about 64% of the county. Next is the Rome Formation at 12%.

Against the rest of Virginia

Radford city ranks 8 of 133 in Virginia for soluble rock at the surface, and sits above 95% of US counties on that measure.