SinkholeOdds

Sinkhole risk in Medina 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
37%
At or near the surface
37%
Buried under cover
0%

The next step for one property

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 496 of Medina County's 1,325 square miles on soluble rock, 496 of them with the rock at or near the surface. With about 55,619 residents (42 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 353 map points about 1.9 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Medina County

The nearest county rated sinkhole country is Runnels County, TX, about 180 miles north. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

What Medina County is built on

The largest mapped soluble unit here is the Devils River Limestone (limestone), Early Cretaceous; Comanchean Series in age, covering about 10% of the county. Next is the Glen Rose Limestone at 9%.

The county also lies over the Gulf Coast salt domes, 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

Medina County ranks 71 of 254 in Texas for soluble rock at the surface, and sits above 83% of US counties on that measure.