Watch out below: identifying the signs of a sinkhole

Published 11:38 am Tuesday, April 29, 2014

Cambrian Ridge Drive in Pelham was the site of a large, 22-foot-deep sinkhole found under the road's pavement. (Contributed)

Cambrian Ridge Drive in Pelham was the site of a large, 22-foot-deep sinkhole found under the road’s pavement. (Contributed)

By MOLLY DAVIDSON / Staff Writer

PELHAM—After the heavy flooding on April 7, a sinkhole opened up on Cambrian Ridge Drive in Pelham. What appeared to be a small depression turned out to be a 22-foot-deep hole disguised by the pavement.

“A resident called in and told our supervisor he thought (the depression) was growing,” Pelham director of Public Works Eddy Jowers said.

When Jowers and the Public Works department arrived on the scene, they found a “slight depression” in the pavement of Cambrian Ridge Drive, 24 inches across and about four inches deep.

They created a hole in the pavement to examine the depression, revealing they were “standing on top of a void,” four feet wide and 22 feet deep. The Public Works department fixed the situation using two truckloads of concrete to “plug the hole.”

Although the Cambrian Ridge Drive sinkhole was unusual due to its “fairly large” size, Jowers said sinkholes are common in this area due to the limestone bedrock underlying much of Shelby County.

“Most times (sinkholes are caused by) washing away of limestone rock formations,” Jowers said. “Water running across creates erosion, once a weakness is formed, water and dirt can find a way through.”

This erosion occurs over “eons,” Jowers said, but a sinkhole “can happen anytime” and anywhere.

Although there is no way to accurately predict when and where a sinkhole might occur, Jowers said they are more common after “long periods of rain,” as the dirt is “saturated,” thus heavier and more malleable.

There are also several signs to look for that may indicate a sinkhole.

In an area uncovered by pavement, a sinkhole may cause a bowl-shaped depression. “The ground will appear to be crumbling into a hole” and trees will be leaning, Jowers said.

On a paved road, Jowers said to “look for any depression that is holding water.” Although it “may be nothing,” Jowers and the Public Works department monitor these areas for growth.

If a sinkhole is suspected near a road or a structure, call the police immediately, and they will alert the Public Works department. Although the Public Works office may be closed, Jowers said there is “someone on call 24/7,” and they will respond.