SinkholeOdds

Sinkhole risk in Wayne County, MI: 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
61%
At or near the surface
0%
Buried under cover
61%

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 371 of Wayne County's 612 square miles on soluble rock. With about 1,771,063 residents (2,895 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 257 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and why the 61% under cover still counts.

Counties around Wayne County

The nearest county rated sinkhole country is Monroe County, MI, about 28 miles southwest, close enough that the same rock may run under the county line. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

What Wayne County is built on

The largest mapped soluble unit here is the Dundee Limestone (limestone), Middle Devonian in age, covering about 22% of the county. Next is the Traverse Group at 21%.

13% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

The county also lies over the Michigan Basin; Ohio Basin; Appalachian Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Michigan

Wayne County ranks 82 of 83 in Michigan for soluble rock at the surface, and sits above 0% of US counties on that measure.