Milford's Complicated Beaver Dam Removal Plan Moves Ahead

MILFORD, MA — A group of large and industrious semiaquatic rodents have touched off a complicated legal and environmental project in Milford.

A group of beavers recently constructed a large dam across a culvert that passes under Alder Street in Medway just west of I-495. The dam caused Stall Brook to overflow, flooding Maple Street in Milford, which is about a 1/2-mile from the dam as the crow flies.

Milford Town Engineer Elizabeth Mainini went to the Select Board Monday seeking permission to approach the Medway Conservation Commission about removing the dam. Medway is requiring Milford to take responsibility for any damage to either Alder Street or the culvert while performing the work. Milford previously received an emergency beaver/muskrat removal permit from its neighbor to the east.

Although small — typically about 3 feet long, and can weight up to 65 pounds — compared to the size of municipal government, beavers routinely cause headaches in communities across the state. In 2021, a beaver dam broke near Warren, flooding the entire downtown.

Massachusetts has strict beaver laws (yes, that's what they're called) that spell out how and when beavers can be captured, and where they can be moved to. Local boards of health are the only entities authorized to issue emergency removal permits outside the annual trapping season between November and April.

Trapping and removal is often the best solution for a beaver problem, according to state wildlife experts. Destroying a dam can trigger beavers to simply rebuild, and they can do it in a few hours.

According to Mainini, the town has already captured and removed the beavers, leaving their empty dam in place. The structure, which is about as high as the roadway, can still cause flooding in its vacant state, she said.

The town will also have to hire an environmental consultant to oversee the dam deconstruction. If removed too fast, pooled water behind the dam could cause more flooding, Mainini said.

"If you remove too much too quickly, that can absolutely cause a great deal of damage," she told the select board.