CHESTERVILLE — Residents were told Thursday night that a new, $1.7 million Dutch Gap Bridge will restore the natural flow of Little Norridgewock Stream, a tributary to the Sandy River that a state official said is the best salmon river in Maine.

The twin metal culverts, installed in 1949, are corroded and too small, creating holes and erosion downstream, according to the Maine Department of Transportation.

The culverts will be replaced with a 75-foot span, with concrete abutments, according to Joseph Stilwell of the state highway department. The bridge will be 25 feet wide, with steel guardrails.

The life expectancy of the bridge is at least 75 years.

Federal highway funds will pay 80 percent of the cost and Maine highway funds the rest.

The design, by Hoyle, Tanner & Associates of Portsmouth, New Hampshire, meets Maine Department of Transportation’s agreement with the U.S. Fish and Wildlife Service.

“Little Norridgewock Stream is a tributary of the Sandy River,” Stilwell said. “The Sandy River is the highest-quality salmon river in the state.”

The design will restore the natural stream crossing, improve water flow and reduce the possibility of debris jams near the bridge.

The design should also reduce the number of car-deer collisions, Project Manager Aron Lachance said.

“They can go underneath it,” he said.

Final design and permitting should be completed by October and bid requests sent out in November. Construction is expected to start next spring. Most of the work will be completed by the fall of 2019.

During construction, a one-lane, temporary bridge will be installed.

“A two-lane bridge was considered,’ Lachance said, “but traffic volumes didn’t warrant it.”

pharnden@sunmediagroup.net

Project Manager Aron Lachance of Hoyle, Tanner & Associates of Portsmouth, New Hampshire, shows slides Thursday night of the deteriorated Dutch Gap Bridge in Chesterville. The company has designed a new bridge over the Little Norridgewock Stream. (Pam Harnden/Livermore Falls Advertiser)