Abstract: A dredging system operates entirely by siphon action and includes a completely sealed conduit system having the intake end disposed upstream or at an upper level from the outlet end which is disposed sufficiently below the inlet end to maintain a flow of water once started. A pump and bypass system is provided for starting the system in operation with the pump bypassed once the system begins this operation. The system is designed to operate continuously without the need for auxiliary power at dams and reservoirs and the like.