Sinkhole risk in Anderson County, TN: Sinkhole country

Sinkhole country

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

On soluble rock: 50%
At or near the surface: 50%
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 169 of Anderson County's 337 square miles on soluble rock, 169 of them with the rock at or near the surface. With about 81,449 residents (242 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 437 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 Anderson County

The closest county with no soluble rock mapped is Morgan County, TN, about 25 miles west. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Knox County, TN 17 mi southeast · 95% at surface
Campbell County, TN 20 mi north · 28% at surface
Union County, TN 23 mi northeast · 89% at surface
Morgan County, TN 25 mi west · under 1% at surface
Roane County, TN 26 mi southwest · 74% at surface
Loudon County, TN 27 mi south · 99% at surface

What Anderson County is built on

The largest mapped soluble unit here is the Chickamauga Group, includes Upper part of Chickamauga Group (Reedsville Shale, and Unnamed limestone unit) and Middle and Lower part of Chickamauga Group (Moccasin Formation, Bays Formation, Ottosee Shale, Holston Formation, Lenoir Limestone, Athens (limestone), Ordovician in age, covering about 12% of the county. Next is the Copper Ridge Dolomite at 12%.

Against the rest of Tennessee

Anderson County ranks 48 of 95 in Tennessee for soluble rock at the surface, and sits above 87% of US counties on that measure.