Sinkhole risk in Howard 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: 25%
At or near the surface: 25%
Buried under cover: 0%

The next step for one property

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 221 of Howard County's 901 square miles on soluble rock, 221 of them with the rock at or near the surface. With about 30,833 residents (34 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 392 map points about 1.5 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Howard County

The nearest county rated sinkhole country is Coke County, TX, about 55 miles southeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Mitchell County, TX 30 mi east · 70% at surface
Borden County, TX 30 mi north · 57% at surface
Glasscock County, TX 30 mi south · 24% at surface
Martin County, TX 31 mi west · 3% at surface
Sterling County, TX 39 mi southeast · 55% at surface
Dawson County, TX 42 mi northwest · 3% at surface

What Howard County is built on

The largest mapped soluble unit here is the Dockum Group, undivided (fine-grained mixed clastic), Late Triassic in age, covering about 18% of the county. Next is the Edwards Limestone at 6%.

The county also lies over the Permian Basin, Anadarko Basin,Dalhart Basin, Palo Duro Basin, 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

Howard County ranks 92 of 254 in Texas for soluble rock at the surface, and sits above 77% of US counties on that measure.