Your Waterwheel Solution
The cross flow turbines are impulse turbines and were developed in this century. In the cross flow the water , in the form of a sheet, is directed into the blades tangentially at about mid way on one side. The flow of water "crosses" through the empty center of the turbine and exits just below the center on the opposite side. Thus the water strikes blades on both sides of the runner. It is claimed that the entry side contributes about 75% of the power extracted from the sheet of water and that the exit side contributes the remainder. The cross flow is an impulse turbine and requires a high head to be really efficient but it will "work" on heads as low as 3'. It can be fabricated in home shops and many have been built . The designer of the home plans claim a 60% efficiency for home built turbines. There are commercial built cross flow turbines that can deliver higher efficiencies, on ideal sites.
