Sinkhole risk in Petersburg city, VA: Pockets of it

Pockets of it

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

On soluble rock: 17%
At or near the surface: 17%
Buried under cover: 0%

What this means before you buy

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 4 of Petersburg city's 23 square miles on soluble rock, 4 of them with the rock at or near the surface. With about 34,058 residents (1,499 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 585 map points about 0.2 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 Petersburg city

The nearest county rated sinkhole country is Hertford County, NC, about 62 miles south. None of the 6 closest counties land in the same band, so Petersburg city stands out from its surroundings.

Colonial Heights city, VA 4 mi north · 12% at surface
Hopewell city, VA 8 mi northeast · 14% at surface
Prince George County, VA 10 mi east · 13% at surface
Chesterfield County, VA 16 mi northwest · 2% at surface
Dinwiddie County, VA 16 mi southwest · under 1% at surface
Henrico County, VA 17 mi north · 7% at surface

Which formation it is

The largest mapped soluble unit here is the Chesapeake Group (sand), Tertiary in age, covering about 15% of the county. Next is the Lower Tertiary Deposits at 2%.

Against the rest of Virginia

Petersburg city ranks 48 of 133 in Virginia for soluble rock at the surface, and sits above 73% of US counties on that measure.