I agree- but I don't think anyone is saying it is right for every dam. However, a lot of dams probably just aren't worth it on net when you do consider all of t

I agree- but I don't think anyone is saying it is right for every dam. However, a lot of dams probably just aren't worth it on net when you do consider all of the factors, and massively decreasing prices of alternatives. There aren't really solutions for migratory fish that support the kind of populations the rivers supported without dams... especially the ancient and poorly designed dams already in place. For example historical estimates are that ~16 million salmon migrated in the Columbia river despite being a major food source for a large number of Native Americans over a massive area. Nowadays, with every practical measure in place, lot of hatcheries, and almost no fishing those numbers are only up to ~1 million. Obviously we're probably not going to return to ~16 million, but the impacts of not doing so are widespread and far lasting- for example salmon coming upstream are historically a major source of nitrogen for the forests in the northwest, and without them long term, the forests will be something substantially different and diminished - with far reaching impacts on the entire ecosystem and many other resources of value to humans[1]. Gradual loss of the deep soil and peat from those forests also causes flooding and drought as the soil no longer stores large amounts of moisture that is slowly released over the dry season- e.g. ecological changes from dams may in the long term actually make flooding and drought more severe rather than less. [1] "total annual growth per unit forest area (m2·ha−1·yr−1) was more than three times higher at spawning sites relative to reference sites" https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/0012-9658%282001%29082%5B2403%3AEOSDNO%5D2.0.CO%3B2 https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890...