Abstract: A system for cyclically lifting a large volume of water includes a piston plate having first and second sides. The water to be lifted exerts a water pressure on the second side of the piston plate, while compressed air held in a pressurized tank exerts an air pressure on the first side of the piston plate. The resultant pressure differential ?p is such that the piston plate is biased to move in a particular direction. A force actuator is provided that periodically exerts a force F on the piston plate to overcome the bias of ?p and thereby lift the volume of water.