Sinkhole risk in Anderson County, KS: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 55%
At or near the surface: 55%
Buried under cover: 0%

The next step for one property

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 319 of Anderson County's 580 square miles on soluble rock, 319 of them with the rock at or near the surface. With about 7,908 residents (14 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 400 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 Anderson County

The closest county with no soluble rock mapped is Nemaha County, NE, about 153 miles north. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Allen County, KS 23 mi south · 90% at surface
Franklin County, KS 24 mi north · 33% at surface
Coffey County, KS 24 mi west · 53% at surface
Linn County, KS 24 mi east · 69% at surface
Woodson County, KS 34 mi southwest · 40% at surface
Bourbon County, KS 35 mi southeast · 68% at surface

The rock underneath

The largest mapped soluble unit here is the Lansing Group (shale), Middle Pennsylvanian- Missourian in age, covering about 29% of the county. Next is the Kansas City Group at 24%.

Against the rest of Kansas

Anderson County ranks 22 of 105 in Kansas for soluble rock at the surface, and sits above 89% of US counties on that measure.