Sinkhole risk in Delta 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: 4%
At or near the surface: 4%
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 10 of Delta County's 257 square miles on soluble rock, 10 of them with the rock at or near the surface. With about 5,647 residents (22 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 479 map points about 0.7 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 Delta County

The nearest county rated sinkhole country is Grady County, OK, about 170 miles northwest. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Hopkins County, TX 18 mi south · 24% at surface
Lamar County, TX 20 mi north · 7% at surface
Fannin County, TX 29 mi northwest · 25% at surface
Hunt County, TX 30 mi southwest · 2% at surface
Franklin County, TX 30 mi southeast · 31% at surface
Rains County, TX 36 mi south · 0% at surface

What Delta County is built on

The largest mapped soluble unit here is the Pecan Gap Chalk (limestone), Late Cretaceous; Gulfian Series in age, covering about 4% 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

Delta County ranks 125 of 254 in Texas for soluble rock at the surface, and sits above 61% of US counties on that measure.