Sinkhole risk in Concho County, TX: Pockets of it

Pockets of it

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

On soluble rock: 67%
At or near the surface: 67%
Buried under cover: 0%

What to do about a house in Concho County

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 656 of Concho County's 984 square miles on soluble rock, 656 of them with the rock at or near the surface. With about 3,326 residents (3 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 381 map points about 1.6 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Concho County

The nearest county rated sinkhole country is Runnels County, TX, about 37 miles north, close enough that the same rock may run under the county line. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Menard County, TX 30 mi south · 93% at surface
McCulloch County, TX 31 mi east · 48% at surface
Tom Green County, TX 36 mi west · 35% at surface
Runnels County, TX 37 mi north · 52% at surface
Schleicher County, TX 49 mi southwest · 95% at surface
Coleman County, TX 51 mi northeast · 36% at surface

Which formation it is

The largest mapped soluble unit here is the Edwards Limestone (limestone), Early Cretaceous in age, covering about 33% of the county. Next is the Lueders Formation at 9%.

3% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

Against the rest of Texas

Concho County ranks 25 of 254 in Texas for soluble rock at the surface, and sits above 92% of US counties on that measure.