A complete reconstruction of the aging Saw Mill Road bridge is nearing the final stage of planning, with work anticipated to begin as early as this coming spring.

The bridge spans the West River, just north of Saw Mill Road’s intersection with Hubbard Road.

A regular state assessment found that the bridge was in need of replacement, which prompted the town to seek public input and then solicit a project design back in 2017. A contract was awarded to HAKS Engineers in November of 2017.

Town Engineer Janice Plaziak said that design is now 70 percent complete, which means the next step is a mandatory review by the state Department of Transportation to ensure compliance with grants and other sources of funding.

Preceding that review, the town has also updated the project’s cost based on the more detailed designs, Plaziak said, with the price now estimated at $2.46 million, up from the preliminary estimate of $2.29 million.

Federal funding will cover 80 percent of the total cost of the bridge replacement, Plaziak said, with the town responsible for the other 20 percent. The town’s share of the project cost is covered by a grant from the state Local Capital Improvement Program, according to Plaziak.

Plaziak said the $170,000 increase in the estimate was due to a number of factors. Limiting the environmental impact of the construction played a large part, she said.

The bridge will actually be longer than originally anticipated in order to prevent its interfering with West River, according to Plaziak.

“We systematically do work to our bridges,” said Plaziak. “And replacements are becoming warranted. This is a small bridge, a relatively small bridge. One of the challenges is the alignment of the road, too. There is some road reconstruction, it’s not just the replacement of the bridge.”

Former town engineer Jim Portley said decking was last replaced on the bridge in the 1960s.

Looking forward, Plaziak said she hopes to put the project out to bid over the winter and have construction beginning in spring.

“I don’t see any reason why we won’t be holding to that schedule at this point, but once it’s out of our hands for reviews, you never know what might come up,” Plaziak said.

Once construction begins the bridge will be entirely closed, which means drivers will need to take detours either on Route 77 or Long Hill Road, Plaziak said. First Selectman Matt Hoey said the town has already held public meetings to address some of the possible traffic snags.

“Obviously, the bridge has to come down,” said Hoey. “It’s going to mean folks will have to be routed around it. So it will be some inconvenience for folks who live immediately adjacent to it.”

But for the most part, he said, people have expressed happiness that work is going to start on the project.

“That bridge is going to be made safer and more reliable,” said Hoey.