"Ways and ways. If I knew how big it was I could refill it; if I try that blind I might pop the sucker. Will Nel mind if I dam the river as long as they get the same amount of total water directed back along the same channel by the time it gets to them? Collecting energy from falling water is one of the best sources of tame lightning. I can also do floating windcatchers and solar panels but you'd want lots of them and they have a little eyesore problem - like, I can do pretty solar panels but you are kind of already using your roofspace more than I'm accustomed to humans doing."