SinkholeOdds

Sinkhole risk in Leon County, FL: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock
100%
At or near the surface
43%
Buried under cover
57%

What this means before you buy

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

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 668 of Leon County's 668 square miles on soluble rock, 288 of them with the rock at or near the surface. With about 300,488 residents (450 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 559 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: what Florida insurers have to cover, and why gypsum and salt move faster than limestone.

Counties around Leon County

The nearest county rated sinkhole country is Decatur County, GA, about 34 miles northwest, close enough that the same rock may run under the county line. 5 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 Hawthorn Group, Torreya Formation (limestone), Eocene in age, covering about 49% of the county. Next is the Hawthorn Group, Torreya Formation at 38%.

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

Leon County ranks 32 of 67 in Florida for soluble rock at the surface, and sits above 85% of US counties on that measure.