Sinkhole risk in Warren County, OH: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 100%
At or near the surface: 0%
Buried under cover: 100%

What this means before you buy

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 401 of Warren County's 401 square miles on soluble rock. With about 256,059 residents (638 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.

Worth reading for this county: why the 100% under cover still counts, and the signs to look for and how an inspection works.

Counties around Warren County

The nearest county rated sinkhole country is Kenton County, KY, about 39 miles southwest, close enough that the same rock may run under the county line. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Clinton County, OH 20 mi east · 0% at surface
Butler County, OH 21 mi west · 0% at surface
Greene County, OH 23 mi northeast · 0% at surface
Montgomery County, OH 24 mi north · 0% at surface
Hamilton County, OH 25 mi southwest · 2% at surface
Clermont County, OH 26 mi south · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Waynesville and Arnheim Formations, Undivided (shale), Ordovician in age, covering about 45% of the county. Next is the Grant Lake and Fairview Formations, Miamitown Shale, Undivided at 26%.

Against the rest of Ohio

Warren County ranks 83 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.