A sinkhole that opened up at the foot of Canal Street Friday (April 29) will take up to six months and $5 million to repair, city officials said.
The collapse, which caved in a 30-foot-wide section of one of New Orleans busiest streets, happened just a few feet away from the spot where Mayor Mitch Landrieu and his infrastructure team had been standing hours earlier in a 50 year-old tunnel that runs underneath the road.
The team was on site to inspect one of the tunnel’s walls, which had begun to buckle earlier this month, allowing water to spill in. A few hours after they left, the wall collapsed, taking the road along with it.
“This is nothing short of incredible,” Landrieu said. “Unfortunately, it’s not a surprise,” given the city’s creaking infrastructure and unstable soil, he said. “Still, I’ve never seen anything like it.”
The tunnel was constructed in the 1960s as part of an abandoned plan to build a six-lane, elevated Riverfront Expressway that would have run alongside the French Quarter, connecting Elysian Fields Avenue to the West Bank. The expressway never happened, but the idea wasn’t scrapped until after the city had already built the tunnel section, which runs between Canal and Poydras streets.
On the Uptown side of Canal Street, which runs directly over the tunnel, tour buses continued to trundle along as normal. On the downtown side, visitors gawked at the crumbling pit that had opened up at the tunnel’s northern end.
Officials said repairs will begin immediately, but it’s possible the sinkhole could continue to grow. The tunnel itself, part of which has been converted into valet parking for Harrah’s Casino, was not thought to be in immediate danger, they said.
The 700-foot-long, 98-foot-wide tunnel was built from concrete supported by steel I-beams. Well mostly. Its two ends were capped with a “temporary wall” made of wood. The curtains were meant to be reopened when the rest of the expressway was constructed.
When the federal government scrapped the expressway plan in 1969, nobody bothered to dig up Canal Street and fill in the tunnel’s end with something more durable.
Time, meanwhile, began to take its toll. Water lines leaked. Drainage culverts running under Canal Street did likewise.
Earlier this month, the city discovered that the temporary wall was buckling. Fearing a collapse, it shut down the lake-bound, lanes of Canal Street so engineers could investigate the problem and begin planning repairs.
Those repairs didn’t come in time.
The timber wall, visible from the street through the massive sinkhole, didn’t look more than a few inches thick. Braced by steel beams only every 10-15 feet, an entire section had given way.
“Evidently, there was a massive leak. That leak seeped into the ground and compromised” the temporary wall, Landrieu said.
Landrieu attributed the leak to damage leftover to the city’s water system after Hurricane Katrina. “We have about 40 percent of our water bleeding out of our pipes under the city of New Orleans,” he said.
Landrieu asked for patience as the city works to repair the street, which will require the “temporary” wall to be replaced with something stronger than wooden sheets.
“This is not a short term fix. This is a three- to six-month fix. It’s a major infrastructure breach that has to be repaired and it’s going to be expensive,” he said.