SinkholeOdds

Sinkhole risk in Milam 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
11%
At or near the surface
11%
Buried under cover
0%

The next step for one property

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

That works out to roughly 115 of Milam County's 1,016 square miles on soluble rock, 115 of them with the rock at or near the surface. With about 26,159 residents (26 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 557 map points about 1.4 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Milam County

The nearest county rated sinkhole country is Runnels County, TX, about 191 miles northwest. 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 11% 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

Milam County ranks 115 of 254 in Texas for soluble rock at the surface, and sits above 69% of US counties on that measure.