Sinkhole risk in Jefferson County, WV: 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 this means before you buy

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

That works out to roughly 176 of Jefferson County's 209 square miles on soluble rock, 176 of them with the rock at or near the surface. With about 61,264 residents (293 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 516 map points about 0.6 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Jefferson County

The closest county with no soluble rock mapped is Montgomery County, MD, about 37 miles east. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Berkeley County, WV 13 mi northwest · 44% at surface
Clarke County, VA 15 mi southwest · 74% at surface
Winchester city, VA 19 mi southwest · 90% at surface
Loudoun County, VA 20 mi southeast · 7% at surface
Washington County, MD 21 mi north · 61% at surface
Frederick County, VA 23 mi west · 30% at surface

Which formation it is

The largest mapped soluble unit here is the Conococheague Formation (limestone), Cambrian in age, covering about 30% of the county. Next is the Elbrook Formation at 19%.

Against the rest of West Virginia

Jefferson County ranks 1 of 55 in West Virginia for soluble rock at the surface, and sits above 95% of US counties on that measure.