SinkholeOdds

Sinkhole risk in Macomb 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
5%
At or near the surface
0%
Buried under cover
5%

What to do about a house in Macomb County

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

That works out to roughly 24 of Macomb County's 479 square miles on soluble rock. With about 886,175 residents (1,849 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 319 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and why the 5% under cover still counts.

Counties around Macomb County

The nearest county rated sinkhole country is Lapeer County, MI, about 33 miles northwest, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Bedford Shale (shale), Upper Devonian in age, covering about 5% of the county.

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

Macomb County ranks 55 of 83 in Michigan for soluble rock at the surface, and sits above 0% of US counties on that measure.