A fish pumping system for moving upload water and fish includes a buffer pipe section having an upstream end and a downstream end. An inlet valve assembly is at the upstream end and provides fluid communication between the buffer pipe and an upstream fish origin. An outlet valve assembly is at the downstream end 5 and provides fluid communication between the buffer pipe and a fish destination. An inlet branch pipe is in fluid communication with the upstream end and an outlet branch pipe is in fluid communication with the downstream end. A production water piping circuit is in communication with the inlet branch pipe and the outlet branch pipe and forms a loop with the buffer pipe section. The 10 production water circuit pumps production water into the buffer pipe section through the inlet branch pipe and out from the buffer pipe section through the outlet branch pipe.
