SinkholeOdds

Sinkhole risk in Gray County, TX: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock
2%
At or near the surface
2%
Buried under cover
0%

What to do about a house in Gray County

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 19 of Gray County's 926 square miles on soluble rock, 19 of them with the rock at or near the surface. With about 20,888 residents (23 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 396 map points about 1.5 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 how these percentages are measured.

Counties around Gray County

The nearest county rated sinkhole country is Donley County, TX, about 31 miles south, close enough that the same rock may run under the county line. None of the 6 closest counties land in the same band, so Gray County stands out from its surroundings.

What Gray County is built on

The largest mapped soluble unit here is the Quartermaster Formation and Whitehorse Group, undivided (mixed clastic/carbonate), Permian; Guadalupe Series in age, covering about 2% of the county.

2% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

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

Gray County ranks 135 of 254 in Texas for soluble rock at the surface, and sits above 58% of US counties on that measure.