“It’s one of the biggest bangs for the buck in terms of the amount of restoration you can get, for one intervention,” Purinton said, adding that his division has 30 potential dam projects but lacks the money to dismantle them.
In some cases, the removals have delivered human benefits as well as ecological ones. Purinton’s division and its partners spent $650,000 to remove the Briggsville Dam in Clarksburg, Mass., this year, $100,000 less than what it would have cost to bring it up to code. In past years, the dam had raised the river’s level, which caused it to jump its banks during storms. Last month the town avoided flooding from Hurricane Irene because the dam was gone, he said.
Maryland officials are working with environmental groups and federal officials to dismantle at least three of the four dams on the Patapsco River, which flows into the Baltimore harbor. For years officials had tried, with little success, to use fish ladders to help shad, herring and eel, which need to swim upstream to spawn, traverse the aging structures. Last year, they used $3.3 million in federal funds to take down two of the dams and are now hoping to dismantle the Bloede Dam downstream, which generated power for a only few years in the early 1900s.