In June, 18 years after workers built the parking lot for the Raleigh Grande multiplex theater off Lynn Road, a small hole developed in the asphalt.
The hole quickly grew to about 20 feet across, a crater that emerged mysteriously and today remains behind fences that block off about a third of the parking lot.
Engineers solved the mystery when they peered into the hole, down about 20 feet to a large, corrugated metal drainage pipe at the bottom. There, on top of the 60-inch pipe, was a gash, about 2 feet long, that was probably made by a piece of equipment during construction and then covered up.
For 18 years, bits of soil filtered into the gash whenever it rained hard and the pipe filled with water, said Robert Crane, president of Carolina Cinemas, the company that owns the theater.
“And as it did, it created a void above the pipe, and it just took 18 years for that void to reach the surface,” Crane said.
Crane says new pipe has been ordered, and he hopes to make the hole disappear within a month.
It’s taken this long to fix in part because Crane had hoped the city of Raleigh would take responsibility for the hole. After all, the drainage pipe also accepts water from surrounding properties and from nearby Hilburn Drive.
The city does offer financial assistance for stormwater repairs on private property, said Blair Hinkle, Raleigh’s stormwater program manager. In this case, the stormwater advisory commission recommended the city offer $75,000 to help offset the repair costs, which the city estimated at $280,000, Hinkle said.
But that money would come with conditions. Carolina Cinemas would have to make the repairs to city standards with city oversight and agree that the city was not liable for maintenance. The city would require concrete pipe, instead of metal, and two new manholes, adding to the expense, Crane said.
In the end, because of the strings attached, the company decided to find its own contractor to make the repairs, at a cost of “well over” $100,000, Crane said.
The expense is minor compared with the $3.7 million that Carolina Cinemas is spending to renovate the 16-screen theater, with plush new seats, 36 taps of beer, two bars and a full kitchen. Half the screens are closed for the upfit work, helping ease the demand for parking in the sinkhole-shrunken lot.
This part of North Carolina isn’t prone to natural sinkholes like those that occur in places such as Florida, said Hinkle. When one does develop, it’s usually because a joint between old pipes underground has begun leaking, creating a small hole or a depression in the pavement.
“We don’t see it on this scale very often,” he said. “This is a different circumstance.”