I have had the same thought my idea was to create a system that hydrolic ram pump filled a water storage 200 gal plus 40 feet or so high. have a float regulated valve to release the water through a many micro hydros in series.
the other idea was so have a hydrolic ram in series with our spring to fill the tanks that would supply water to the house. i then put a micro hydro in the main going to the house water and one in the spill over. so we would recieve power wether it was suppling water to the house or the excess. something similar for the rain runoff storage and spill over as well.
so ya critiques welcome