SinkholeOdds

Sinkhole risk in Pawnee 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
11%
At or near the surface
0%
Buried under cover
11%

What to do about a house in Pawnee County

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

That works out to roughly 49 of Pawnee County's 431 square miles on soluble rock. With about 2,521 residents (6 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 390 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and why the 11% under cover still counts.

Counties around Pawnee County

The nearest county rated sinkhole country is Dickinson County, KS, about 100 miles southwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Chase Group (limestone), Permian in age, covering about 11% of the county. Next is the Shawnee Group at under 1%.

The county also lies over the Northern Anadarko Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Nebraska

Pawnee County ranks 75 of 93 in Nebraska for soluble rock at the surface, and sits above 0% of US counties on that measure.