[perrygeo]

Most implementations of hydroelectric power involve cutting off and severely degrading the habitat of aquatic life, both upstream and downstream. Societies depend on these resources so it's hard to justify calling hydro power sustainable in a general sense. To those negatively impacted by the dam, it rightly feels like a ruthless power grab by outsiders coming to steal water and energy without any thought for the livelihoods that are destroyed.

Of course hydro power can be done correctly, assuming the collaboration of all the stakeholders in the watershed and careful tradeoffs. How many dams were built with such an equitable process?

Given hydro power's well-documented negative impacts, and our arsenal of other truly renewable energy sources, damming new rivers should be a last resort. In the US at least there is a strong trend of dam removal - many ill-considered hydro projects are costly to maintain, an economic loss to society as a whole, and a detriment to the environment. Quite far from any feasible definition of "renewable resource".