SinkholeOdds

Sinkhole risk in Macon County, TN: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock
24%
At or near the surface
24%
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 74 of Macon County's 307 square miles on soluble rock, 74 of them with the rock at or near the surface. With about 27,189 residents (89 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 318 map points about 1.0 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 Macon County

The nearest county rated sinkhole country is Trousdale County, TN, about 13 miles southwest, close enough that the same rock may run under the county line. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

The rock underneath

The largest mapped soluble unit here is the Ordovician [units] including Richmond Group (which includes Mannie Shale, Fernvale Limestone, Sequatchie Formation, and Arnheim Formation), the Maysville Group (which includes Leipers Formation), the Eden Group (which includes Inman Formation), and (shale), Ordovician in age, covering about 21% of the county. Next is the Silurian Formations, including Decatur Limestone, Brownsport Group (Lobelville Formation, Bob Limestone, Beech River Formation), Wayne Group (Dixon Formation, Lego Formation, Waldron Shale, Laurel Limestone, Osgood Formation) and Brassfield Limestone at 3%.

Against the rest of Tennessee

Macon County ranks 63 of 95 in Tennessee for soluble rock at the surface, and sits above 77% of US counties on that measure.