Sinkhole risk in Simpson County, KY: Sinkhole country

Sinkhole country

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

On soluble rock: 99%
At or near the surface: 99%
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 231 of Simpson County's 234 square miles on soluble rock, 231 of them with the rock at or near the surface. With about 20,350 residents (87 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 272 map points about 0.9 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 Simpson County

The closest county with no soluble rock mapped is Hopkins County, KY, about 66 miles northwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Logan County, KY 18 mi northwest · 93% at surface
Warren County, KY 20 mi northeast · 89% at surface
Sumner County, TN 20 mi south · 70% at surface
Allen County, KY 22 mi east · 51% at surface
Robertson County, TN 22 mi southwest · 92% at surface
Butler County, KY 33 mi north · 20% at surface

The rock underneath

The largest mapped soluble unit here is the Ste. Genevieve and St. Louis Limestones, undivided (limestone), Mississippian in age, covering about 92% of the county. Next is the Salem, Warsaw, and Harrodsburg Limestones, undivided at 4%.

Against the rest of Kentucky

Simpson County ranks 2 of 120 in Kentucky for soluble rock at the surface, and sits above 99% of US counties on that measure.