SinkholeOdds

Sinkhole risk in Brevard 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
66%
At or near the surface
40%
Buried under cover
26%

What to do about a house in Brevard County

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 673 of Brevard County's 1,015 square miles on soluble rock, 408 of them with the rock at or near the surface. With about 658,447 residents (649 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 249 map points about 2.0 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 Brevard County

The nearest county rated sinkhole country is Indian River County, FL, about 42 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

What Brevard County is built on

The largest mapped soluble unit here is the Shelly sediments of Plio-Pleistocene age (beach sand), Holocene in age, covering about 25% of the county. Next is the Shelly sediments of Plio-Pleistocene age at 21%.

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

Brevard County ranks 36 of 67 in Florida for soluble rock at the surface, and sits above 84% of US counties on that measure.