Sinkhole risk in Shelby 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 to do about a house in Shelby County

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

That works out to roughly 408 of Shelby County's 408 square miles on soluble rock. With about 47,952 residents (118 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 351 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Shelby County

The nearest county rated sinkhole country is Kenton County, KY, about 99 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Auglaize County, OH 16 mi north · 1% at surface
Miami County, OH 20 mi south · 0% at surface
Logan County, OH 23 mi east · 0% at surface
Darke County, OH 26 mi southwest · 0% at surface
Mercer County, OH 26 mi northwest · 3% at surface
Champaign County, OH 27 mi southeast · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Lockport Dolomite (dolostone (dolomite)), Silurian in age, covering about 44% of the county. Next is the Salina Group at 35%.

Against the rest of Ohio

Shelby County ranks 75 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.