InfrastructureMapping Florida sinkholes

Published 15 July 2014

Sinkholes are common in Florida because of porous rock underground, such as limestone, which holds water. Over time, acid in the water dissolves the rock, creating a void. The Florida Geological Surveyand Florida Department of Emergency Managementare making progress on creating a statewide map showing where sinkholes are most likely to form. Florida received more than $1 million in federal funding last year to conduct a three-year study which would eventually help emergency planners predict where sinkholes are likely to develop, especially after large rainstorms.

The Florida Geological Survey and Florida Department of Emergency Management are making progress on creating a statewide map showing where sinkholes are most likely to form. Florida received more than $1 million in federal funding last year to conduct a three-year study which would eventually help emergency planners predict where sinkholes are likely to develop, especially after large rainstorms.

They’re prepared for floods. They’re prepared for downed power lines,” but the sinkhole vulnerability map will provide preparation for ground collapse, said Alan Baker, a state geologist.

To date, geologists have sampled and studied 230 locations in Columbia, Hamilton, and Suwannee counties, the results of which have contributed to a “relative vulnerability” map that has proved 93 percent successful in the initial study areas that sinkholes will form, state geologist Clint Kromhout said.

According to the Tampa Tribune, geologists will now conduct the study statewide, while Kromhout and Baker plan to hire additional geologists and work with local governments. “The ultimate desire is to have a statewide map to reduce the risk of loss of life and property,” Kromhout said. The planned statewide map will identify sinkhole vulnerabilities at the county level, but Kromhout hopes technology will soon allow geologists to prepare a neighborhood-by-neighborhood detailed map.

The 2012 Tropical Storm Debby, which caused dozens of sinkholes, motivated the state to conduct the study. Sinkholes are common in Florida because of porous rock underground such as limestone that holds water. Over time, acid in the water dissolves the rock, creating a void. When the earth above the limestone gets too heavy, it can cave in, creating a sinkhole. The Tampa Bay counties of Hillsborough, Pasco, and Hernando are known as “Sinkhole Alley.” Roughly 66 percent of all sinkhole damage reported in the state between 2006 and 2010, occurred in those counties according to the Florida Office of Insurance Regulation.

Some lawmakers proposed to create a sinkhole repair program for policyholders of the nonprofit government operated Citizens Property Insurance Corporation (CPIC), to ensure that sinkhole damage is fixed properly. The lawmakers were concerned of the misuse of funds from insurance payouts. Sinkhole claims have also resulted in a number of lawsuits against CPIC by customers claiming bad repairs or repairs that took too long. The proposed program would have required sinkhole fixes be conducted by approved contractors.

A version of the bill passed the Florida House but died in the Senate, where some lawmakers questioned its effectiveness.