Sinkhole risk in Clark County, OH: 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: 100%
At or near the surface: 0%
Buried under cover: 100%

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 396 of Clark County's 396 square miles on soluble rock. With about 134,985 residents (341 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 302 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Clark County

The nearest county rated sinkhole country is Kenton County, KY, about 79 miles southwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Champaign County, OH 15 mi north · 0% at surface
Greene County, OH 17 mi south · 0% at surface
Madison County, OH 20 mi east · 0% at surface
Miami County, OH 25 mi west · 0% at surface
Montgomery County, OH 29 mi southwest · 0% at surface
Fayette County, OH 30 mi southeast · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Cedarville, Springfield, and Euphemia Dolomites, Undivided (dolostone (dolomite)), Silurian in age, covering about 31% of the county. Next is the Cincinnati Group as used by Wickstrom (1990) at 29%.

Against the rest of Ohio

Clark County ranks 19 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.