Dam Being Removed in Lisbon

In Lisbon today, the Pearl Lake Brook Dam will begin coming down and a brook that was blocked for over seventy years will flow once more. The 14-foot high and 21-foot long dam was built in 1935 to create a settling basin for the town’s water supply and fell into disrepair after becoming unneeded in 1981.

The decision to restore the brook and remove the dam began in 2005 when the Director of Lisbon’s Public Works, Kevin Klement, contacted the state’s Department of Environmental Service (DES) Dam Removal and River Restoration Program about the unnecessary structure.

“This was an ideal dam to consider for removal because it had not been utilized for its intended purpose for over 25 years,” said Deb Loiselle of the DES Dam Bureau. “The town had no present or future plans to utilize it as such or for other purposes. Dam removal has extraordinary ecological benefits so it is a win-win situation. After reviewing all of the information pertaining to removing versus maintaining the dam, the town decided to pursue removal.”

Pearl Lake Brook is a tributary to the Ammonoosuc River and the removal of the dam will eliminate a barrier to resident and migrating species. The DES claims that while there are ecological benefits from removing the barrier, there will also be improved water quality. Oftentimes the temperature of the water around a dam will artificially rise and dissolved oxygen levels will be lower than ideal.

“The dam removal on Pearl Lake Brook will benefit the aquatic life in many ways. From facilitating fish passage to the restoration of stream connectivity, impacts of this project will be positive in many ways,” said Andy Schafermeyer, NH Fish and Game Department Fisheries Biologist.

The Pearl Lake Brook Dam is not the only dam in the state being looked at, but is the first to be brought down in 2008. “This is the first of several dams to be removed in New Hampshire during 2008, and the ninth dam to be removed since the inception of DES Dam Removal and River Restoration Program,” says Loiselle. “Many more projects are being considered and are at various stages of implementation.”