Sinkhole risk in Douglas County, MO: Sinkhole country

Sinkhole country

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

On soluble rock: 100%
At or near the surface: 100%
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 814 of Douglas County's 814 square miles on soluble rock, 814 of them with the rock at or near the surface. With about 12,290 residents (15 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 375 map points about 1.5 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 Douglas County

The closest county with no soluble rock mapped is Van Buren County, AR, about 94 miles south. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Ozark County, MO 21 mi south · 100% at surface
Wright County, MO 22 mi north · 100% at surface
Webster County, MO 30 mi northwest · 100% at surface
Taney County, MO 36 mi southwest · 100% at surface
Howell County, MO 37 mi east · 100% at surface
Christian County, MO 37 mi west · 98% at surface

The rock underneath

The largest mapped soluble unit here is the Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (dolostone (dolomite)), Early Ordovician-Ibexian Series in age, covering about 61% of the county. Next is the Roubidoux Formation at 34%.

Against the rest of Missouri

Douglas County ranks 5 of 115 in Missouri for soluble rock at the surface, and sits above 99% of US counties on that measure.