Micro-Hydro A micro-hydro system uses water to turn a turbine or water wheel which in turn turns a generator thus producing power. Head pressure and flow volume are the important considerations in a micro-hydro system. A minimum vertical head drop of 10 feet is recommended to create the force necessary for a turbine system to produce power, with a greater drop capable of producing more power. Water wheels can produce power with less head pressure. For more information on this, you may want to check this out.
While micro-hydro systems can be an excellent source of consistent power, debris, flooding, drought and freezing are all issues which need to be addressed when designing the system.