Sinkhole risk in Cass County, NE: 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: 44%
At or near the surface: 0%
Buried under cover: 44%

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 245 of Cass County's 557 square miles on soluble rock. With about 27,492 residents (49 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 343 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 44% under cover still counts, and how these percentages are measured.

Counties around Cass County

The nearest county rated sinkhole country is Knox County, NE, about 149 miles northwest. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Sarpy County, NE 14 mi north · 0% at surface
Otoe County, NE 19 mi south · 0% at surface
Douglas County, NE 27 mi north · 0% at surface
Mills County, IA 29 mi east · 0% at surface
Lancaster County, NE 30 mi west · 0% at surface
Fremont County, IA 31 mi east · 0% at surface

What Cass County is built on

The largest mapped soluble unit here is the Shawnee Group (limestone), Late Pennsylvanian- Virgilian in age, covering about 36% of the county. Next is the Lansing Group at 6%.

Against the rest of Nebraska

Cass County ranks 43 of 93 in Nebraska for soluble rock at the surface, and sits above 0% of US counties on that measure.