Sinkhole risk in Houston County, TN: Sinkhole country

Sinkhole country

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

On soluble rock: 68%
At or near the surface: 68%
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 136 of Houston County's 200 square miles on soluble rock, 136 of them with the rock at or near the surface. With about 8,538 residents (43 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 249 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Houston County

The closest county with no soluble rock mapped is Henry County, TN, about 33 miles west. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Stewart County, TN 13 mi northwest · 71% at surface
Humphreys County, TN 18 mi south · 45% at surface
Dickson County, TN 21 mi southeast · 79% at surface
Montgomery County, TN 23 mi northeast · 94% at surface
Benton County, TN 25 mi southwest · 11% at surface
Henry County, TN 33 mi west · under 1% at surface

Which formation it is

The largest mapped soluble unit here is the St. Louis Limestone and Warsaw Limestone (limestone), Mississippian in age, covering about 67% of the county. Next is the Ordovician formations, including Mannie Shale, Fernvale Limestone, Hermitage Formation, and Carters, Lebanon, Ridley, Pierce, and Murfreesboro Limestones at under 1%.

Against the rest of Tennessee

Houston County ranks 34 of 95 in Tennessee for soluble rock at the surface, and sits above 92% of US counties on that measure.