According to the Kardashev scale, a Type 3 civilization can capture all the energy emitted by its galaxy — even that from black holes.
But how much energy can be drawn from only one large waterfall? I don't know, but it’s more than enough to power this steampunk mountain village!

Welcome to Himmelfall, where the rocky landscape, huge cliffs and blasting waterfalls were not already exciting enough - so they built a huge bronze rollercoaster throughout their land!