Sinkhole risk in Nance County, NE: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 32%
At or near the surface: 31%
Buried under cover: under 1%

The next step for one property

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 140 of Nance County's 442 square miles on soluble rock, 136 of them with the rock at or near the surface. With about 3,262 residents (7 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 325 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Nance County

The nearest county rated sinkhole country is Kearney County, NE, about 79 miles southwest. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Merrick County, NE 16 mi south · 79% at surface
Boone County, NE 21 mi north · 0% at surface
Polk County, NE 26 mi southeast · 2% at surface
Platte County, NE 28 mi northeast · 19% at surface
Howard County, NE 30 mi southwest · 11% at surface
Greeley County, NE 30 mi west · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Niobrara Formation (limestone), Late Cretaceous in age, covering about 31% of the county. Next is the Pierre Shale at under 1%.

Against the rest of Nebraska

Nance County ranks 14 of 93 in Nebraska for soluble rock at the surface, and sits above 80% of US counties on that measure.