SEFFNER, Fla. — A sinkhole opening in your yard or neighborhood is most Floridians' worst nightmare.
An expert tells us that even when a sinkhole is repaired, there's no guarantee that it'll be fixed forever.
The gaping hole in the center of two fences appeared Monday night in the same spot as the massive sinkhole that swallowed Jeffrey Bush in February 2013.
Bush was sleeping in his bedroom when his floor collapsed.
His body was never recovered.
That home was demolished, and the sinkhole was filled with 150 tons of gravel.
At the time, Hillsborough County reported the stabilization cost was $90,000.
“It’s not a surprise that it would reoccur,” said geotechnical engineer Darrell Hanecki.
He said the process called “backfilling” the sinkhole stabilized it but didn’t permanently fix it.
“You just don’t want to have an open hole sitting there, but putting a couple of hundred thousand dollars doing a permanent grout repair may not be a practical answer,” Hanecki said.
Hanecki said backfilling sinkholes that occur in roads in Central Florida has been a reliable and cost-effective solution and the repairs can last for years or even permanently.
Compaction grouting is the preferred method of repairing a sinkhole, which involves pumping grout into the ground and filling cavities and holes in the bedrock.
“Grouting is, in my mind, a permanent fix. I’ve never had one reoccur. And I don’t know of any that have reoccurred that were properly grouted,” Hanecki said.
Hanecki has designed and supervised hundreds of compaction grouting repairs.
But he said people often try to avoid paying the high price of that type of repair, which can cost far more than the home is worth.
So they pay a contractor to stabilize the foundation using a process called underpinning.
By doing so, homeowners can reclassify sinkhole homes as “repaired” on county appraiser sites, which track whether homes have documented sinkholes.
“People believe that that’s some sort of sinkhole repair and it couldn’t be further from the truth,” Hanecki said.
An underpinned home where a sinkhole had been previously detected collapsed in the Lake Padgett neighborhood in 2017.
Luckily no one was injured.
Engineers are now evaluating how to repair the sinkhole in Seffner.
It's not the first time.
In 2015, a small sinkhole opened up on the site and was filled again.
But Hanecki said that doesn't mean neighbors should worry.
“I wouldn’t say there’s any reason to be fearful. Sinkholes are a natural hazard in Florida. They can occur in vast swaths of the state,” Hanecki said. “Just because your neighbor has a sinkhole doesn’t mean you will. And just because no one in your area does have a sinkhole doesn’t mean you won’t.”
If you have a story you’d like the I-Team to investigate, email us at adam@abcactionnews.com
