State Looks at Louisiana Highway 70 Detour Options Near Sinkhole

A growing sinkhole just south of Louisiana Highway 70 in has raised worries in Assumption Parish about subsidence that could cut off the highway and force commuters and school buses to make a 90-minute-plus detour.

In response, the state Department of Transportation and Development is in the early stages of a two-tiered plan that would include a temporary detour that could be built quickly if needed, followed by a more-permanent bypass.

The Advocate reports that reception to the proposals, which were unveiled last month, has been divided.

Some want a proposed four-mile-long bypass farthest from the sinkhole built right away, while others, including business people on Highway 70, favor a shorter, temporary detour.

No cost estimates or time lines are yet available.

“We are examining both options because we do not know what, if any, impacts there will be from the sinkhole to infrastructure in the area,” Dustin Annison, DOTD spokesman, said in an email.

These days, a closure on Louisiana Highway 70 can mean drivers will spend an hour and a half or more heading north through White Castle and Bayou Pigeon or south through Morgan City to travel between Pierre Part and Napoleonville, two communities that are just 19 miles apart.

Annison added that any new route “would only be built if it were necessary to close La. 70.”

The northern edge of the sinkhole is 1,100 feet from the highway, parish officials said, and the sinkhole has been growing southward, away from La. 70.

Annison said ongoing monitoring of La. 70 and its bridges shows they are not subsiding.

But sitting in a front-porch chair last week at his home in Pierre Part off La. 70, Herman Mabile, 75, said DOTD needs to build the longer route soon.

“That mess right there, you can’t control it,” he said. “There’s no way they can control that hole right there.”

Police Jury President Martin “Marty” Triche said a temporary detour seems to be the most practical way to keep traffic flowing. He said he has heard constituent concerns about the permanent routes cutting off Bayou Corne and businesses.

“I am kind of like them (DOTD officials), sitting, looking and evaluating all the options,” he said.