Sinkhole risk in Hancock County, IA: 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: 88%
At or near the surface: 0%
Buried under cover: 88%

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 500 of Hancock County's 571 square miles on soluble rock. With about 10,616 residents (19 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 391 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Hancock County

The nearest county rated sinkhole country is Clayton County, IA, about 123 miles east. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Winnebago County, IA 21 mi north · 0% at surface
Wright County, IA 24 mi south · 0% at surface
Cerro Gordo County, IA 25 mi east · 0% at surface
Kossuth County, IA 26 mi west · 0% at surface
Humboldt County, IA 31 mi southwest · 0% at surface
Worth County, IA 32 mi northeast · 0% at surface

What Hancock County is built on

The largest mapped soluble unit here is the Lime Creek Formation (limestone), Late Devonian in age, covering about 45% of the county. Next is the Kinderhook Series at 22%.

Against the rest of Iowa

Hancock County ranks 47 of 99 in Iowa for soluble rock at the surface, and sits above 0% of US counties on that measure.