SinkholeOdds

Sinkhole risk in Franklin 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
31%
At or near the surface
31%
Buried under cover
0%

What this means before you buy

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 88 of Franklin County's 284 square miles on soluble rock, 88 of them with the rock at or near the surface. With about 10,912 residents (38 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 379 map points about 0.9 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 Franklin County

The nearest county rated sinkhole country is Cherokee County, OK, about 189 miles north. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Which formation it is

The largest mapped soluble unit here is the Midway Group, undivided (fine-grained mixed clastic), Paleocene in age, covering about 31% 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

Franklin County ranks 83 of 254 in Texas for soluble rock at the surface, and sits above 80% of US counties on that measure.