Sinkhole risk in Webster 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: 78%
At or near the surface: 78%
Buried under cover: 0%

What this means before you buy

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 450 of Webster County's 575 square miles on soluble rock, 450 of them with the rock at or near the surface. With about 3,326 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 414 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Webster County

The nearest county rated sinkhole country is Franklin County, NE, about 24 miles west, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Adams County, NE 23 mi north · 79% at surface
Nuckolls County, NE 24 mi east · 52% at surface
Franklin County, NE 24 mi west · 78% at surface
Smith County, KS 31 mi southwest · 40% at surface
Jewell County, KS 31 mi southeast · 32% at surface
Kearney County, NE 33 mi northwest · 47% at surface

What Webster County is built on

The largest mapped soluble unit here is the Niobrara Formation (limestone), Late Cretaceous in age, covering about 75% of the county. Next is the Pierre Shale at 3%.

3% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

Against the rest of Nebraska

Webster County ranks 4 of 93 in Nebraska for soluble rock at the surface, and sits above 94% of US counties on that measure.