OK, we have a new place with a creek that runs through it. There's an
abundant flow, but the greatest drop I can exploit is about 6 feet. I'm
going to use a 3" pipe to lead water to a certain level, then let the water
drop in a Ferris wheel type of waterwheel. Let's ignore any contribution of
the forward momentum of the water, so that all the energy comes from the tubs
of water falling downward. Also, a 3" pipe is wide enough that little energy
is lost through friction. On the one hand, if I make the pipe steeper, a
greater volume of water will flow per unit of time. On the other hand, I
would be depriving the "Ferris wheel" of the necessary "head" to get much
energy out of it.
[Homestead] Waterwheel Riddle,
WILLIAM JONES, 06/26/2012