Sinkhole risk in Lucas 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: 79%
At or near the surface: 0%
Buried under cover: 79%

What to do about a house in Lucas County

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

That works out to roughly 267 of Lucas County's 340 square miles on soluble rock. With about 426,291 residents (1,255 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 437 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 79% under cover still counts, and how these percentages are measured.

Counties around Lucas County

The nearest county rated sinkhole country is Monroe County, MI, about 16 miles north, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Monroe County, MI 16 mi north · under 1% at surface
Wood County, OH 24 mi south · 0% at surface
Ottawa County, OH 25 mi east · 0% at surface
Sandusky County, OH 28 mi southeast · 0% at surface
Fulton County, OH 34 mi west · 0% at surface
Lenawee County, MI 35 mi northwest · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Tymochtee and Greenfield Formations, Undivided (dolostone (dolomite)), Silurian in age, covering about 30% of the county. Next is the Salina Group at 20%.

Against the rest of Ohio

Lucas County ranks 50 of 88 in Ohio for soluble rock at the surface, and sits above 0% of US counties on that measure.