Environmental concerns are driving the removals, not lifespan issues that had led these efforts in the past.
"Of the 900 dams that have ever been removed from American rivers, half have come down in the last 10 years. There have always been those who railed against them-fishermen, for example, and environmentalists-but most of the dams removed prior to the 1990s were breached in the interest of public safety, sacrificed to prevent another flood like the one in 1889 when a Johnstown, Pennsylvania, dam was breached, killing 2,200 people. The majority removed recently, like the Edwards, have been torn down in the name of fish."
