Sinkhole risk in Calumet County, WI: 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: 80%
At or near the surface: 0%
Buried under cover: 80%

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 256 of Calumet County's 318 square miles on soluble rock. With about 53,602 residents (168 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 358 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Calumet County

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

Winnebago County, WI 23 mi west · under 1% at surface
Fond du Lac County, WI 26 mi southwest · 0% at surface
Outagamie County, WI 27 mi northwest · 0% at surface
Brown County, WI 29 mi north · under 1% at surface
Manitowoc County, WI 32 mi east · under 1% at surface
Sheboygan County, WI 34 mi southeast · 0% at surface

What Calumet County is built on

The largest mapped soluble unit here is the Silurian, undivided (dolostone (dolomite)), Silurian in age, covering about 49% of the county. Next is the Maquoketa Formation at 22%.

Against the rest of Wisconsin

Calumet County ranks 30 of 72 in Wisconsin for soluble rock at the surface, and sits above 0% of US counties on that measure.