That's an amazing video shot by photographer Andy Maser of the Condit Dam being breached by explosives last month. The 125-foot tall dam, built in 1913 on the White Salmon River in Washington State, emptied the contents of its reservoir in just over two hours.
For the first time in nearly one hundred years the White Salmon River will flow freely, restoring the river to be a natural habitat for local fish species. From the Seattle Times:
Located three miles from the river's confluence with the Columbia, taking out the dam is expected to reopen about 33 miles of habitat for steelhead and about 14 miles for chinook, depending on how well different runs of fish contend with natural falls in the river.
It's amazing just how much silt has accumulated over the past century, which reduced the generation capacity over time, and helped hasten the dam's removal. The electric utility that owns the Condit Dam found it cheaper to demolish the dam than bring it up to modern environmental standards.
This video is yet another reminder that all forms of energy have tradeoffs - even relatively clean ones like hydroelectricity.