Engineer: Replace Sewalls Falls Bridge
Cousins Tyler Harriman, 21, far right, of Canterbury, and Dominic Denico, 10, on left, from Vassalboro, Maine, fish on the Merrimack river below the Sewalls Falls Bridg on Wednesday, June 18, 2012. (Amanda Steen/ Monitor Staff) Purchase photo reprints at PhotoExtra »
Removing and replacing the Sewalls Falls Bridge is Concord’s best option for the deteriorating steel truss structure, the city engineer told Heritage Commission members yesterday.
“I support the replacement,” City Engineer Ed Roberge said. “From an engineering perspective, safety and stability is first and foremost in my mind.”
A rehabilitation of the 1915-era bridge over the Merrimack River has been planned for years, but the city council voted in August to reconsider about a dozen different options after a new structural analysis revealed the bridge was in worse condition than expected.
The Concord City Council will likely select a final plan next month for the bridge. Roberge said other options include constructing a two-lane bridge next to the existing bridge while maintaining it as a pedestrian crossing, or moving forward with a 2006 plan to rehabilitate the bridge and build a second one-way bridge alongside it.
Members of the Heritage Commission yesterday declined to vote on a preferred plan, but did not express strong opposition to the recommendation.
“It seems like given the realities of this one, nobody’s going to get in the way of what has to happen here, but we would like to have a voice in how that may happen,” said Phil Donovan, the commission’s chairman.
Roberge told the Heritage Commission that since August’s city council vote, a new review focused on the bridge’s historical aspects.
If the bridge were rehabilitated, “repairs to the trusses may be so extensive or intrusive that the historic integrity of the bridge is lost,” according to the review by Historic Documentation Company Inc. of Portsmouth, R.I.
Roberge said a plan for the bridge must address three issues: safety, stability, and the city’s long-term development plans that could bring increased traffic to Sewalls Falls Road.
The Sewalls Falls Bridge is “non-redundant,” Roberge said; if just one critical element breaks due to age, disrepair or a car accident, the entire structure could collapse into the Merrimack River. Modern bridges are built with more stability, he said.
Even maintaining the structure as a pedestrian walkway would require significant repairs, he said.
“We’re talking about . . . hundreds of thousands of dollars to keep that maintained as a pedestrian bridge,” he said.
The state Department of Transportation’s capital plan includes nearly $15.2 million for the project in 2014 and 2015.
Rehabilitating the bridge would cost more than planned, Roberge said, and maintenance costs would continue to mount.
“While the reports indicate that the bridge can practically be renovated or rehabilitated, it doesn’t really address the structural concerns . . . how do we bring this bridge up to date and then maintain it, and then compare that not only to the additional capital cost, but also the long-term maintenance costs of the bridge?” he said.
Replacing the bridge is the least expensive option, Roberge said, and would have a smaller environmental impact than the other two alternatives. Building a bridge next to the existing structure would impact a residential property, the Monitor’s property and wooded land belonging to the federal government’s Land Conservation Investment Program.
If the bridge is removed, the state would require documentation of its history, Roberge said. He added that the city would likely find additional ways to remind residents about the historic Sewalls Falls Bridge.
Heritage Commission member Carol Brooks asked whether parts of the existing bridge could be used as a pedestrian walkway in another location along the Merrimack River.
“It’s really difficult to find that specific of an application for its use,” Roberge said, but added that the city could develop creative reuses such as turning the bridge’s granite center into a fishing platform.
Heritage Commission members expressed concern yesterday about the aesthetics of a new bridge. Modern highway bridges are practical, but “they’re just functional structures and that’s it,” Fred Richards said.
Brooks suggested that a new bridge could incorporate pieces of the current bridge, to “give a nod” to its history.
Roberge assured the commission that if the city council chooses to replace the bridge, the city can design an attractive new structure.
“I would recommend getting it out of there and replacing it with something that 100 years from now will be looked at the same way we look at this bridge,” said Donovan, the commission’s chairman.
City officials will hold a meeting Jan. 23 for residents to learn and share their thoughts about the bridge, Roberge said, with a city council vote planned for Feb. 11.