Sinkhole risk in Champaign 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: 99%
At or near the surface: 0%
Buried under cover: 99%

What to do about a house in Champaign County

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

That works out to roughly 425 of Champaign County's 429 square miles on soluble rock. With about 38,907 residents (91 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 337 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 99% under cover still counts, and how these percentages are measured.

Counties around Champaign County

The nearest county rated sinkhole country is Kenton County, KY, about 93 miles southwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Clark County, OH 15 mi south · 0% at surface
Logan County, OH 18 mi north · 0% at surface
Union County, OH 24 mi northeast · 0% at surface
Miami County, OH 25 mi west · 0% at surface
Madison County, OH 25 mi southeast · 0% at surface
Shelby County, OH 27 mi northwest · 0% at surface

What Champaign County is built on

The largest mapped soluble unit here is the Salina Group (dolostone (dolomite)), Silurian in age, covering about 25% of the county. Next is the Tymochtee and Greenfield Formations, Undivided at 24%.

Against the rest of Ohio

Champaign County ranks 18 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.