TOPSHAM — The town plans early next summer to replace an approximately 50-year-old culvert that runs about 700 feet in the Lower Village.

The Board of Selectmen on Dec. 5 unanimously accepted a nearly $469,000 bid from St. Laurent & Sons Construction to install a smooth-bore plastic pipe that is 42 inches in diameter. The existing pipe consists of a combination of steel and cement, and “the cement bells have separated and the metal has rusted out in several places,” Public Works Director Dennis Cox said Dec. 12.

In the only other bid submitted, Crooker Construction said it would do the project for approximately $523,000.

Town Meeting voters in 2017 approved budgeting $265,000 for the replacement culvert, based on cost estimates at the time. David Douglass, chairman of the Board of Selectmen, recalled seeing a video presented by Cox two or three years ago that showed the deteriorating condition of the interior of the culvert. Roots were growing down through the pipe, stymying proper flow.

Still, the culvert “wasn’t in danger of immediate failure,” he said, and the town held off on the work until officials decided whether to make Elm Street Extension, which leads up to Main Street, a two-way road; selectmen recently chose not to.

“If we were going to make changes to Elm Street Extension, we didn’t want to tear things up multiple times,” Douglass said. “… We thought we would kill two birds with one stone, which then, in turn, bit us because construction costs have gone up so much; that’s the harm of an improving economy, that everyone’s so busy and so many projects are happening.”

That strong construction economy led to project costs that nearly doubled since two years ago, according to Town Manager Rich Roedner. With money already budgeted for the work, the balance could either be allocated in Topsham’s fiscal year 2021 budget, or come from the town’s tax increment financing economic development reserve, which as of June 2018 had about $475,000, Roedner told selectman last week; the June 2019 audit has yet to be completed.

The culvert now starts on the north side of Elm Street Extension, runs parallel to part of Main Street, crosses under Main Street and discharges in the area of the “Granny Hole” – part of the former channel which separated Bowdoin Mill Island from the mainland.

The town has known for years that improvements to the system were in the pipeline, Roedner said in 2017; it was a project highlighted when Topsham created the downtown TIF district.