Abstract: A water powered sump pump having an ejector with an inlet end and a discharge end and enclosed within a housing providing support for the ejector. A control chamber about the inlet end of the ejector has a diaphragm valve which operates to control communication with a water pressure source responsive to operation of a float controlled pilot valve. Multi-stage turbulence and progressively increasing energy and velocity is effected in sump water directed to a propulsion zone defined about the ejector nozzle and communicating with the mouth end of a venturi leading to a discharge outlet from the ejector.