Sinkhole risk in Fredericksburg city, VA: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock: 10%
At or near the surface: 10%
Buried under cover: 0%

What this means before you buy

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 1 of Fredericksburg city's 10 square miles on soluble rock, 1 of them with the rock at or near the surface. With about 29,992 residents (2,870 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 610 map points about 0.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Fredericksburg city

The nearest county rated sinkhole country is Clarke County, VA, about 63 miles northwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Stafford County, VA 9 mi north · 23% at surface
Spotsylvania County, VA 12 mi southwest · 5% at surface
King George County, VA 18 mi east · 45% at surface
Caroline County, VA 20 mi south · 48% at surface
Prince William County, VA 28 mi north · 2% at surface
Charles County, MD 28 mi northeast · 15% at surface

The rock underneath

The largest mapped soluble unit here is the Lower Tertiary Deposits (sand), Tertiary in age, covering about 7% of the county. Next is the Chesapeake Group at 4%.

Against the rest of Virginia

Fredericksburg city ranks 57 of 133 in Virginia for soluble rock at the surface, and sits above 68% of US counties on that measure.