Sinkhole risk in Pottawattamie 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: 71%
At or near the surface: 0%
Buried under cover: 71%

What to do about a house in Pottawattamie County

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

That works out to roughly 679 of Pottawattamie County's 951 square miles on soluble rock. With about 93,529 residents (98 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 370 map points about 1.6 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Pottawattamie County

The nearest county rated sinkhole country is Knox County, NE, about 150 miles northwest. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Mills County, IA 22 mi south · 0% at surface
Shelby County, IA 26 mi northeast · 0% at surface
Harrison County, IA 28 mi northwest · 0% at surface
Montgomery County, IA 30 mi southeast · 0% at surface
Cass County, IA 32 mi east · 0% at surface
Douglas County, NE 32 mi west · 0% at surface

What Pottawattamie County is built on

The largest mapped soluble unit here is the Kansas City Group (limestone), Late Pennsylvanian-Missouri Series in age, covering about 55% of the county. Next is the Shawnee Group at 12%.

Against the rest of Iowa

Pottawattamie County ranks 80 of 99 in Iowa for soluble rock at the surface, and sits above 0% of US counties on that measure.