A Look Inside Florida’s Sinkholes

Imagine being a resident of The Villages in Florida, the world’s largest retirement community, where you expected to happily live out the balance of your life but now have to face the ever-growing threat of Florida sinkholes possibly swallowing your home. It has already happened a multitude of times to some of the residents and businesses there and even caused some evacuations and one condemnation. The Villages has been called a “hotbed of sinkholes.” It is in Sinkhole Alley, which is a name given to counties in Central Florida that carry the greatest risk; Florida has more sinkholes than any other state.


This is a very scary scenario that is occurring in other areas as well, and people want to know WHY the “ground chasms” are getting worse.


Florida is built on a bedrock of carbonate, primarily limestone, that dissolves in rainwater. The resulting terrain, “karst,” becomes honeycombed with cavities. When the cavities become too large, they give way, collapse the sand and clay above, and leave a cavernous surface hole.


The main trigger for sinkholes is too much or too little water. During a drought, such as the one Central Florida experienced at the beginning of 2017, cavities supported by groundwater empty and become unstable. Alternatively, during a heavy rainstorm or the intense rainfall such as September’s Hurricane Irma that hit The Villages, the sudden influx of water could possibly wash out the cavities.


A field study by the National Cave and Karst Research Institute reported that man-made development is actually the most persistent factor for the increase in sinkholes. New buildings’ weights press down on weak spots, equipment scrapes away protective layers of soil, paved roads and parking lots divert rainwater, and other factors.


The Villages was the fastest-growing metropolitan area in the United States from 2013 through 2016, and its population has grown to over 125,000. In 2017 it had a 93 percent boom in home construction, and new purchases of land will bring 28,000 more homes. Retention ponds, irrigating new golf courses, and the community’s lawns with water being pumped from the aquifer could open up sinkholes. By 2017 that water use reached 12.4 billion gallons a year.


Neighboring counties have also made it high on the RiskMeter’s list of Florida’s most sinkhole-prone counties. That included a 260-foot-wide sinkhole in Pasco County, the largest there in 30 years.


Is there anything that can be done? A company that specializes in assessing a property’s sinkhole risk uses ground penetrating radar (GPR), the best way to detect cavities, but Florida law doesn’t require it. Homeowners insurance only covers if a sinkhole makes the home uninhabitable. Additional sinkhole insurance has a deductible set typically at 10 percent of the home’s value, and not all homes qualify. Even when a sinkhole is repaired/remediated, it could sometimes reopen.


Even though the annual sinkhole property damage is at least $300 million, and that damage could go up as climate change intensifies, the state and federal government don’t fund much sinkhole research even though millions of dollars in federal funding go each year to tsunamis, hurricanes, earthquakes, and volcanoes.