SinkholeOdds

Sinkhole risk in Glades 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
69%
Buried under cover
31%

What to do about a house in Glades County

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 807 of Glades County's 807 square miles on soluble rock, 560 of them with the rock at or near the surface. With about 13,132 residents (16 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 314 map points about 1.6 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: what Florida insurers have to cover, and why gypsum and salt move faster than limestone.

Counties around Glades County

The closest county with no soluble rock mapped is Gulf County, FL, about 319 miles northwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Which formation it is

The largest mapped soluble unit here is the Shelly sediments of Plio-Pleistocene age (limestone), Pliocene/Pleistocene in age, covering about 69% of the county. Next is the Shelly sediments of Plio-Pleistocene age at 31%.

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

Glades County ranks 15 of 67 in Florida for soluble rock at the surface, and sits above 92% of US counties on that measure.