Sinkhole risk in Forsyth County, NC: 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: 3%
At or near the surface: 3%
Buried under cover: 0%

What to do about a house in Forsyth County

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

That works out to roughly 10 of Forsyth County's 408 square miles on soluble rock, 10 of them with the rock at or near the surface. With about 398,143 residents (976 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 317 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Forsyth County

The nearest county rated sinkhole country is Pulaski County, VA, about 69 miles north. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Stokes County, NC 18 mi north · 41% at surface
Davie County, NC 21 mi southwest · 0% at surface
Yadkin County, NC 23 mi west · 15% at surface
Davidson County, NC 23 mi south · 0% at surface
Guilford County, NC 26 mi east · 0% at surface
Surry County, NC 31 mi northwest · 12% at surface

The rock underneath

The largest mapped soluble unit here is the Metagraywacke and Muscovite-Biotite Schist (metasedimentary rock), Cambrian/Late Proterozoic in age, covering about 3% of the county.

Against the rest of North Carolina

Forsyth County ranks 56 of 100 in North Carolina for soluble rock at the surface, and sits above 59% of US counties on that measure.