Sinkhole risk in Hamilton 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: 95%
At or near the surface: 80%
Buried under cover: 15%

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 513 of Hamilton County's 542 square miles on soluble rock, 433 of them with the rock at or near the surface. With about 9,564 residents (18 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 283 map points about 1.4 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 15% under cover still counts, and the signs to look for and how an inspection works.

Counties around Hamilton County

The nearest county rated sinkhole country is Kearney County, NE, about 55 miles southwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Merrick County, NE 21 mi north · 79% at surface
York County, NE 22 mi east · 0% at surface
Clay County, NE 24 mi south · 60% at surface
Hall County, NE 25 mi west · 33% at surface
Polk County, NE 32 mi northeast · 2% at surface
Fillmore County, NE 33 mi southeast · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Niobrara Formation (limestone), Late Cretaceous in age, covering about 95% of the county.

Against the rest of Nebraska

Hamilton County ranks 1 of 93 in Nebraska for soluble rock at the surface, and sits above 95% of US counties on that measure.