Sinkhole risk in Falls 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: 14%
At or near the surface: 14%
Buried under cover: 0%

What this means before you buy

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

That works out to roughly 106 of Falls County's 765 square miles on soluble rock, 106 of them with the rock at or near the surface. With about 17,752 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 530 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Falls County

The nearest county rated sinkhole country is Runnels County, TX, about 184 miles west. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

McLennan County, TX 26 mi northwest · 41% at surface
Limestone County, TX 29 mi northeast · 4% at surface
Robertson County, TX 29 mi southeast · 0% at surface
Milam County, TX 32 mi south · 11% at surface
Bell County, TX 36 mi southwest · 32% at surface
Hill County, TX 52 mi north · 22% at surface

Which formation it is

The largest mapped soluble unit here is the Pecan Gap Chalk (limestone), Late Cretaceous; Gulfian Series in age, covering about 12% of the county. Next is the Austin Chalk at 1%.

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

Falls County ranks 109 of 254 in Texas for soluble rock at the surface, and sits above 70% of US counties on that measure.