SinkholeOdds

Sinkhole risk in DeSoto County, FL: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock
100%
At or near the surface
73%
Buried under cover
27%

What this means before you buy

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

Standard Florida homeowners policies cover only catastrophic ground cover collapse; full sinkhole coverage is a separately priced option insurers must offer.

That works out to roughly 635 of DeSoto County's 637 square miles on soluble rock, 464 of them with the rock at or near the surface. With about 36,744 residents (58 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 400 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: what Florida insurers have to cover, and why gypsum and salt move faster than limestone.

Counties around DeSoto County

The closest county with no soluble rock mapped is Gulf County, FL, about 280 miles northwest. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

The rock underneath

The largest mapped soluble unit here is the Hawthorn Group, Peace River Formation (sandstone), Miocene/Pliocene in age, covering about 44% of the county. Next is the Shelly sediments of Plio-Pleistocene age at 29%.

The county also lies over the Floridan shelf, 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 Florida

DeSoto County ranks 14 of 67 in Florida for soluble rock at the surface, and sits above 93% of US counties on that measure.