Sinkhole risk in Kewaunee 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: 99%
At or near the surface: 0%
Buried under cover: 99%

The next step for one property

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

That works out to roughly 338 of Kewaunee County's 342 square miles on soluble rock. With about 20,751 residents (61 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 301 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 99% under cover still counts, and how these percentages are measured.

Counties around Kewaunee County

The nearest county rated sinkhole country is Oceana County, MI, about 85 miles southeast. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Brown County, WI 28 mi west · under 1% at surface
Manitowoc County, WI 32 mi south · under 1% at surface
Door County, WI 39 mi northeast · under 1% at surface
Oconto County, WI 46 mi northwest · under 1% at surface
Outagamie County, WI 52 mi west · 0% at surface
Calumet County, WI 52 mi southwest · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Silurian, undivided (dolostone (dolomite)), Silurian in age, covering about 98% of the county. Next is the Maquoketa Formation at 1%.

Against the rest of Wisconsin

Kewaunee County ranks 44 of 72 in Wisconsin for soluble rock at the surface, and sits above 0% of US counties on that measure.