Abstract: An energy regenerative apparatus for a water hammer type pump includes a water hammer type pump and an engergy regenerative apparatus. The water hammer type pump includes a reservoir which is connected to a pump body by a pipe. A pressure tank is fixed on top of the pump body. A piston rod with a piston head is slidably provided in the pump body. A water passage between the pump body and the pressure tank is controllable by the piston head so as to control a flow of water from the pump body to the pressure tank. A flat valve is disposed between an outlet pipe and the pressure tank so as to prevent any reverse flow of water from the outlet pipe into the tank. A water gate valve is provided for controlling a water passage of the pump body.