Stories of a short, fat bastard.

Hey yeah... you could build and line that with volcanic rock, which is pretty darn impervious!

Also, I read online somewhere about a guy who built a vertical axis water turbine that used a whirlpool like vortex affect... the drop on that was about 2 meters, and the 'chute' was only a metre deep by a couple wide I think. [the feed pool sorta looked like a cutaway diagram of a turbo]...

He got a constant 30 kilowatts off it. Which is enough for couple of houses.

So, imagine an aqueduct a meter deep by say 3 meters wide, and a couple of kilometers of long, feeding water from the lake in a spiraling circle around the island... and every 50 meters or so, a meter wide chute leading to a header pool and a vertical drop through one of those turbines, with pipe and cable feeds off to different houses [sorta a ring and spokes almost].

Water and power distribution, all in one go.

and since you'd need a continuous flow to keep the turbines spinning, you could do that by diverting some of the water to the house via a filtration and sterilization system as drinking water, the rest could flow under it, and out the other side into a contentiously cycling reed bed system, into which the black water waste empties. creating a waste management system. Which, come to think of it.. could also incorporate hydroponic farming as well. [why waste nutrients growing reeds, when you can grow crops instead?]

Viola! Complete start to finish water/waste/power system.