Firm Introduces Florida Sinkhole
Research Tool: Home Buyers can Benefit
By: Dave Hodges
Home buyers, appraisers and lenders have a new tool for researching the presence
of sinkholes for properties in Florida.
FloodInsights, a national provider of flood-zone determinations for real estate,
has added a Florida sinkhole report service based on the locations of more than
15,000 sinkhole and subsidence events across the state.
“I really expect that the appraisal industry would be really interested in this,
as would homeowners,” said Dan Munson, FloodInsights’ founder. The Boston-based
firm had been providing FEMA flood-zone determinations for insurance companies,
but it occurred to Munson that sinkhole risk information would be valuable as
“Many people think that there are just a few counties in Florida that are
affected by sinkholes, but sinkhole risk has been spreading geographically,”
In Leon County, such well-known sites as lakes Jackson, Iamonia and Miccosukee
are there because of sinkhole formation that occurred ages ago — underlying
limestone gave way and the sediments above fell into those voids.
At FloodInsights’ web site, a user can type in an address and obtain both a FEMA
flood report as well as sinkhole information that includes the distance to the
closest sinkhole, the number of sinkholes within a half-mile radius, the number
of sinkholes within a 1-mile radius, and a hazard map. Searches start at $4.95
To have insurance for sinkhole risk, property owners in Florida must have a
rider or addendum to their policies. All insurance companies licensed to do
business in the state must offer sinkhole coverage.
State law specifically defines what constitutes a sinkhole, which is separate
from “catastrophic ground cover collapse” — geological activity that leads to an
abrupt collapse of the ground, a depression in the ground clearly visible,
structural damage to the building, and the insured structure being condemned in
order to be vacated.
FloodInsights has developed a database with more than 15,000 verified sinkholes
or subsidence events, based on information from county records and new incidents
that geologists have evaluated.
The Florida Geological Survey maintains a downloadable database of reported
incidents statewide. The FGS, however, has no legal authority to require that
property owners send in reports on subsidence events that occur, said Harley
Means, assistant state geologist.
Florida’s subsurface geology and karst terrain, the underground expanse of
limestone formations and cavities, is highly variable.
“Just because there are some sinkholes in the area doesn’t mean it will occur on
your property, too,” Means added. “It’s a site-specific thing and one of the
things to caution people about is just that.”