HIGHLANDS COUNTY – Highlands County residents should not go to bed worrying about whether they will wake up having their homes swallowed into a deep sinkhole.
Clint Kromhout, a geologist, said that in fact residents of other counties should not become worried about being the victims of a massive and deep sinkhole like the one near Tampa where a man died last week.
Those types of sinkholes are "extremely rare," said Kromhout, a professional geologist 1 with the Florida Geological Survey, which is part of the Florida Department of Environmental Protection. "You might not see another like that during your lifetime."
Such a massive sinkhole would even be more rare in Highlands County, he said.
Sinkholes are generally formed when the limestone close to the surface is eroded by water and the water is then removed, leaving a cavity that can cause a collapse of the surface.
Kromhout said weight on the surface can also cause a collapse, he said. "They also occur on their own."
The big reason why sinkholes are unlikely to occur in Highlands County, as compared to Hillsborough and Polk counties is geological differences beneath the surface, Kromhout said.
In those counties, the limestone is much closer to the surface that in Highlands County, he said.
That was apparently not the case a million years ago or more when many of the lakes, that were once sinkholes, formed in Highlands County, he said.
The limestone was apparently much closer to the surface then, Kromhout said.
Now, the limestone in Highlands County is deeper and covered by sediments from an ancient mountain range. Those sediments reduce water erosion of the limestone, he added.
In recent years, the only apparent major sinkhole incident in Highlands County occurred in 1989 on Valerie Boulevard north of Sebring where a 20-foot deep sinkhole swallowed up two houses, according to an Associated Press article. No one was injured.
One of the homes was owned by Bill Pivnick and was valued at $70,000.
Kromhout said that sinkholes in Highland County could be wide, but would likely be shallower than a major sinkhole in Hillsborough County.