Repair Work on Mascoma Lake Dam to Continue Through Next Week

Erosion near the Mascoma Lake dam found during a routine inspection will likely take another week to repair, state officials said yesterday.

Steve Doyon, the dam and safety inspection administrator for the New Hampshire Department of Environmental Services, wrote in an email that a recent inspection by dam safety personnel “noted a bit of erosion in the channel” just downstream from the dam. The department notified Lebanon and began repairs on Monday.

Workers restricted the flow of Mascoma Lake into the channel, making it shallower, and fixed the issue. However, during a more in-depth follow-up inspection, more eroded areas were found.

Dan Mattaini, the head of the department’s maintenance and operations section who is overseeing the project, said people living downstream don’t need to worry.

“It currently does not represent a danger, but it does require immediate attention,” he said of the weakened spillway areas in an interview yesterday.

The erosion isn’t extraordinary. Over the course of the coming week, workers will fill in the eroded areas of the spillway apron, or floor, with concrete.

They also will repair the rip rap dislodged by fast-moving water.

Messages left for Jim Angers, the superintendent of Lebanon’s wastewater treatment plant, were not returned yesterday.

Mattaini said that repairs such as these are expected, especially with older dams. The Mascoma Lake Dam was built in 1982.

“Over time you just have to continue monitoring systems,” Mattaini said.

Still, workers from the dam safety and inspection unit had to receive emergency authorization from the department’s wetlands bureau in order to forgo a lengthier permit process.

According to Mattaini, getting to work sooner was of high importance, even if there wasn’t a danger of the dam failing.

“If we let it go further, it would be more expensive,” he said. “It could turn into a situation that would present more danger.”

Yesterday afternoon, the dam and area surrounding it was quiet. A pair of large pumps were set up on the grassy area between the lake and river. An excavator had been parked right on a muddy riverbank, its bucket hanging out over the water.

Jon Wolper can be reached at or 603-727-3248.