> Sure the water in that creek might be falling hundreds of meters, or even kilometers, but without a dam the height differential at your generator is only going to he a few metres at best. Enough to power the lighting, fridge, and washing machine in the houses that the creeks happen to run by, but not much else.

Could be, but that's a bunch of stuff you don't have to power with the existing system. Given how many creeks there are, that seems like it could really add up.

> With the advent of long lasting perovskites and (hopefully) some less polluting battery technologies you're not even better off cost-wise.

That's fair. I've learned in my life that I don't have a good intuition for what the costs of large infrastructure projects are.