SinkholeOdds

Sinkhole risk in Smith County, TX: Not karst, but voids possible

Not karst, but voids possible

No soluble bedrock; some pseudokarst (piping or lava-tube ground).

On soluble rock
0%
At or near the surface
0%
Buried under cover
0%

What this means before you buy

Not true karst, but soil piping or lava tubes can still open voids - mention it to an inspector.

Across 921 square miles, under one square mile of Smith County maps onto soluble rock. With about 249,091 residents (270 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 285 map points about 1.8 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 ground with no limestone still opens up.

Counties around Smith County

The nearest county rated sinkhole country is Grady County, OK, about 237 miles northwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Against the rest of Texas

Smith County ranks 235 of 254 in Texas for soluble rock at the surface, and sits above 0% of US counties on that measure.