BINGHAMTON, NY – (WIVT/WBGH) The last portion of work is underway on the project to repair the troubled tunnel on Chenango Street that was sinking into the earth.

A crew began the process of jackhammering out the temporary concrete base that was installed last year as part of a larger effort to shore up the precast concrete arch underneath Interstate 81 and Route 17.

New permanent concrete will be installed.

A Department of Transportation spokesman says the goal is to complete the work by the middle of next week, employing lane shifts but not lane closures.

The contractor will also be removing portable toilets and construction debris and seeding a mulching grassy areas near the entrances to the tunnel.

In June of 2021, it was discovered that the highway above the arch was sinking due to a design flaw.

The tunnel was subsequently closed for 15 months, from September of 2021 through November of last year while a contractor tried several different strategies to bolster the arch and keep it from sinking any further.

Pouring a new arch within the precast arch ended up being the solution.

Despite the additional layer, the height of the underpass is still above the 14 foot minimum requirement which is why the height is not posted.