Sinkholes and the people who love them

country’s biggest open sinkhole, Golly Hole, opened 52 years ago in Alabama, creating a rift 350 feet wide and 100 feet deep. But even small ones can be horrendously expensive; all told, sinkholes may have cost the country over $300 million annually during the past 15 years. No one maintains a master list of them, and the U.S. Geological Survey says most are probably never reported. Still, there’s enough data to know the majority occur in states like Tennessee, Kentucky, Florida, and Pennsylvania, where soft, porous bedrock is liable to dissolve.

The “sinkhole capital” award might go to Florida, which has seen these craters proliferate after large storms like Tropical Storm Debby in August and Hurricane Milton in October, devouring backyards and chunks of road. Some experts on the matter say that  “sinkhole season” takes over as hurricane season winds down. 

Sinkholes are also complicated to resolve: Many states don’t requireask homeowners’ insurance to cover them, leaving many people to deal with a big problem on their own. Florida and Tennessee are among the few states that require disclosing past occurrences to anyone buying a house, though those laws are antiquated and lawmakers have been pushing for updates.

Regardless of the annoyance, sinkholes have seen a lot of love in Asheville.

Bacchus joined the sinkhole group just after its founding in 2019, when a particularly monstrous example swallowed a parking lot in a cavity 36 feet wide and 30 feet deep. That story made national headlines. The owners of the land tried, without success, to fill it with concrete before the city declared that the building on the site was too dangerous to occupy. It remained vacant for years while the corroded piping that caused the sinkhole was repaired. 

Late last year, a Waffle House in the nearby Mars Hill suffered a similar fate. The day before Helene brought record flooding, a sinkhole took out much of the diner’s parking lot, ultimately leading the owners to shut down. 

Much of Appalachia sits on porous limestone, made of the compressed shells of sea creatures that, millions of years ago, swam and scuttled in shallow seas. This topography, called karst, is full of tunnels and caves. USGS maps paint much of Tennessee, Kentucky, and Virginia in a bright-red high-risk sinkhole zone. The nuisances have threatened, among other things, a Corvette museum in Kentucky, a police station in West Virginia, and a shopping mall in East Tennessee. For years, a sinkhole at the bottom of the Tennessee Valley Authority’s Boone Dam drained it like a bathtub. These geologic formations are an expensive nuisance, and occasionally tragic. A Pennsylvania grandmother died late last year after falling into one while looking for her missing cat.

In Western North Carolina, and other areas with notably no limestone, sinkholes are mainly the result of human intervention – construction fill, bad plumbing, and choices made by developers and builders that result in water going places it shouldn’t. 

However they arise, sinkholes have an insatiable quality to them, often expanding in ways that make them difficult and sometimes impossible to repair. But they also create a sense of wonder and fascination – the feeling of peering into another time. By opening a window into a subterranean world of water, fossils, and caves, they offer a glimpse of what came before.

And, experts say, we might see more of them as a warming world makes big storms more common. Ernst Kastning, a retired geology professor who taught at Radford University in Virginia, said sinkholes are often a natural reaction to a sudden change, like torrential rain. They can form as all that precipitation flows downhill, such as via an underground cave system. “​​The water has to come out somewhere,” Kastning said.