North Main could re-open Thursday

This intersection will soon be busy again as city workers hope to have North Main Street and Cannon Boulevard open by Thursday evening. (T-G Photo by Brian Mosely) [Order this photo]

But five weeks after digging began to repair Shelbyville's underground storm water flume, the work has been completed, and city officials hope to have traffic flowing by Thursday night.

Public works director Mark Clanton said Tuesday that work on the flume itself "is done."

The only thing left to do is to "put in some top soil, do some seeding, then we're done," Clanton said.

Clanton also added that some concrete work will need to be done to repair the sidewalks in the area as well, which will be done this week.

"Barring anything going crazy, hopefully we'll be paving the road Thursday and try to have it open by Thursday afternoon," he said.

The underground flume collapsed after a total of 10 inches of rain fell in early May.

Engineers have speculated that water entered underneath the flume where sewer work was done by contractors working with Shelbyville Power last year.

With the heavy rains, swirling supposedly occurred around the flume and washed away material from the bottom corners of the pipe, which was described as the weakest point of the flume.

With all of the other pressure on the pipe, the water underneath it caused the flume to buckle upwards, it has been speculated.

The 200 feet of damage extended between North Brittain to the middle of North Main Street.

Clanton had praise for everyone involved with the project, adding that engineers had estimated it would take three months or more to complete the repair, but instead, the work was finished in five weeks.

"A big pat on the back to everybody," Clanton said, from Shelbyville Power, Clanton Excavating, Contech, the firm that supplied the pipes, the engineering firm CVC. "Everyone has worked together real well on this project."

But to finish it in the past five weeks "is almost unheard of, to have a project of this magnitude ... with the road and everything else ... it's unheard of," Clanton explained.

The cause of the collapse is still undetermined at this time, Clanton said, with city manager Ed Craig waiting for a report on what may have caused the underground damage.

On June 5, workers discovered that an old sewer line, which was recently replaced by contractors for Shelbyville Power, Water and Sewer, was still open, which could have caused storm water runoff to enter the area surrounding the flume.

"It suggests that during the flood event, when there was an awful lot of pressure, that the water came back through the old line and then washed out somewhere underneath the flume," Craig said at the time.

Craig added that this was just a theory, but apparently when workers installed the new line, in the course of switching over between the old line and the new line, they installed a shut-off valve, "and it appears the valve (on the old line) was left open," he said.