Many dams have high environmental costs that outweigh their value. Removing them is the only sensible answer. And taking them down can often make economic sense as well.
I hate dams. They wreck the land by interrupting the flood cycle and wreck the river by creating an impassible barrier. Fuck flood control, we just need to build in areas that are safe, and treat flood-prone areas as the natural gift that they are.
Way too many river valleys have been destroyed in the name of false security and costly electricity.