Many of the small dams being removed in the state are no longer serving their original functions. Nobody in Pottstown can even remember what the 8-foot tall dam on Manatawny Creek was originally for... but according to Bill Cannon, with the Greater Pottstown Watershed Alliance, dams make life hard on river fish and wildlife by dividing up their habitats.

" In a purely environmental way, they're all bad. But some do serve a purpose for boating. Some dams obviously for hydroelectric power. And some dams for flood control. This was none of those cases."

Scientists from the Academy of Natural Sciences in Philadelphia have been evaluating the dam removal in Pottstown. Researcher David Hart says the creek is returning to a more natural state. But he says many dams in Pennsylvania are being removed for social reasons, not environmental.

" Many of these dams are very old and they're actually creating safety concerns, that people can die going over a dam in a canoe and getting caught in the hydraulic just downstream. And if the dam's in poor repair, sometimes that makes the issues even more complicated."

Hart says each dam is different, and sometimes conditions make it safer to leave dams in place than to remove them. More information's available on the web at GreenWorks.tv. I'm Brad Linder.