I'm not really sure how I feel about hydroelectric being classified as renewable. On one hand it doesn't emit but when you look at projects like the James Bay plant, it's hard to ignore the massive amount of emissions that went into creating the infrastructure and the permanent impact on the landscape.

I'd suppose this is kind of off-topic and is more of a question of how renewable hydroelectric power generation is on a project by project basis based on environmental and ecosystem impact.

Edit: forgot to mention, the impact on indigenous lands as well in many of the colonized countries.