. "A paddle wheel is a form of waterwheel or impeller in which a number of paddles are set around the periphery of the wheel. It has several uses, some of which are: Very low-lift water pumping, such as flooding paddy fields at no more than about 0.5 m (20 in) height above the water source. To move and mix algae culture in the raceway ponds used for algaculture."@en . .