By Bethany Bray
For more than five years, a group of beavers on the Skug River has been doing what beavers do best: building a dam.
This month, the dam grew big enough to flood out the septic system of a resident on Delphi Circle, causing the health department to issue an emergency order to breach the dam.
Over the weekend of Dec. 12, a "beaver deceiver" flow-through device was placed in the dam, located north of Salem Street on the Skug River. On Tuesday, Dec. 15, the Conservation Commission voted to make the breaching of the dam permanent.
A beaver deceiver allows water to flow through a dam and the animals are not able to dam the device, said Bob Douglas, Andover's conservation director.
Flow-through devices have already been placed, with Conservation Commission approval, on beaver dams down and upstream from the Salem Street dam on the Skug River.
"We will now see more even and consistent flow through the length of the Skug River," said Douglas. "This is seen as a good compromise by everybody. We can still use the trails, and a ponded area will remain, but not as large. The beavers can stay where they are and not be trapped out."
Several trails run along the Skug River near the beaver dam, including on town-owned conservation property and land owned by the Andover Village Improvement Society (AVIS). Over the years, trails and boardwalks have been relocated to higher ground twice to escape the beaver's flooding, said Douglas.
Because beavers are a protected animal, special permission must be obtained to breach a dam, he said, and fines run up to $25,000 for tampering with beaver dams.
"We recognize that it's all natural, the flooding cycle," said Douglas. "It takes a very unique set of circumstances for someone to (legally) alter a dam. It's governed by the board of health, and it's usually a substantial threat to property, health or safety."
