Sinkholes in Florida are more common than you think. Here’s why

Florida’s geology plays a big role

A massive sinkhole opens up in Winter Park in 1981.

ORLANDO, Fla. – Growing up in central Florida, it’s likely a story of a sinkhole has come up from time to time. For those who are new to the area, this topic may come as a surprise.

The Sunshine State has plenty of natural wonders from beautiful beaches and stunning springs to amazing wildlife and its fair share of wild weather. Sinkholes, unfortunately, are common too. In fact, Florida has more sinkholes than any other state. We decided to dig into why.

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Florida’s Geology

Under the sand, clay or silt that is plentiful here, is a lot of limestone. In fact, this porous limestone makes up the Florida aquifer system, which is the primary source of our drinking water. It’s one of the largest aquifers in the United States, extending into parts of the Carolinas. When water like rain flows through the porous limestone, it slowly dissolves the aquifer’s limestone forming a landscape called karst, known for springs, streams and even sinkholes. Much of west Central Florida is made up of this landscape, making it very active for sinkhole formation. Pasco, Hillsborough and Hernando counties even make up an area known as “Sinkhole Alley.”

Karst Landscape constitute about 40% of the United Stated east of Tulsa, Oklahoma (USGS)

Sinkhole Formation

When rain falls, it flows through the limestone, often collecting in the cracks known as joints in the stone. As more of the limestone slowly dissolves away, these joints become wider, becoming a weaker support system to anything above it. Eventually, the ground will collapse and cave in, creating the sinkhole.

A heavy overload like water from flooding can trigger a sinkhole, but there are other triggers, too. Pumping water from the ground is another way sinkholes are formed. When the water is sitting in the joints of the limestone, it provides pressure helping to support the ground above it. When that water is pumped out, that pressure is no longer there, leaving a hole or multiple holes in the limestone which are weak and can’t support the weight of whatever is above it. Extended droughts and land development like the construction of retention ponds are other ways sinkholes are commonly created as well.

Popular Sinkhole in Orlando

Lake Eola is actually a sinkhole that Jacob Summerlin, who owned the property at the time, had noticed was forming at the edge of his land.

Over time and with the help of the natural aquifer and flooding storm water, the lake was formed. The strip of land around the lake was donated in 1883 by the Summerlin family for public use and named Lake Eola in memory of Robert Summerlin’s departed sweetheart. Five years later, the lake was recognized as a public park in the City of Orlando.

Sinkhole Damage

Over 40 years ago, in 1981, a sinkhole now known as “Lake Rose” formed in Winter Park, causing $4 million in damage. It swallowed the home of Mae Rose Owens, part of a Porsche dealership, parts of several businesses and a community swimming pool.

A massive sinkhole opens up in Winter Park in 1981.

Because sinkholes can form anywhere in Florida, not just in “Sinkhole Alley,” it’s important to know your risk and to know what’s covered in the event your home is damaged. Not all insurance policies cover damages to your home due to a sinkhole, but Florida Law does require insurance companies to cover “catastrophic ground cover collapse.”

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About the Author:

Emmy Award Winning Meteorologist Samara Cokinos joined the News 6 team in September 2017. In her free time, she loves running and being outside.