Sinkhole risk in Andrews County, TX: Not karst, but voids possible

Not karst, but voids possible

No soluble bedrock; some pseudokarst (piping or lava-tube ground).

On soluble rock: under 1%
At or near the surface: under 1%
Buried under cover: 0%

What to do about a house in Andrews County

Not true karst, but soil piping or lava tubes can still open voids - mention it to an inspector.

That works out to roughly 8 of Andrews County's 1,501 square miles on soluble rock, 8 of them with the rock at or near the surface. With about 18,923 residents (13 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 392 map points about 2.0 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Andrews County

The nearest county rated sinkhole country is Ector County, TX, about 31 miles south, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Gaines County, TX 30 mi north · 0% at surface
Ector County, TX 31 mi south · 38% at surface
Martin County, TX 40 mi east · 3% at surface
Winkler County, TX 41 mi southwest · 12% at surface
Dawson County, TX 50 mi northeast · 3% at surface
Midland County, TX 51 mi southeast · 16% at surface

What Andrews County is built on

The largest mapped soluble unit here is the caliche deposits (evaporite), Pleistocene and Holocene in age, covering about under 1% of the county.

The county also lies over the Permian Basin, Anadarko Basin,Dalhart Basin, Palo Duro Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Texas

Andrews County ranks 141 of 254 in Texas for soluble rock at the surface, and sits above 53% of US counties on that measure.