SinkholeOdds

Sinkhole risk in Dallas 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
39%
At or near the surface
39%
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 336 of Dallas County's 873 square miles on soluble rock, 336 of them with the rock at or near the surface. With about 2,656,028 residents (3,042 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 390 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Dallas County

The nearest county rated sinkhole country is Baylor County, TX, about 152 miles northwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Austin Chalk (limestone), Late Cretaceous; Gulfian Series in age, covering about 39% of the county.

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

Dallas County ranks 65 of 254 in Texas for soluble rock at the surface, and sits above 83% of US counties on that measure.