Systems and methods for controlling fluid flow in an immersion lithography system. The system includes a fluid flow path that allows fluid to flow from a source through a fluid retention hood and then a fluid control valve. The system includes a pressure sensing system for determining a pressure drop across the fluid retention hood. The pressure drop across the fluid retention hood changes with the fluid flow rate. A control system receives signals indicating the pressure drop across the fluid retention hood and produces control signals for the fluid control valve. The control signals adjust the fluid flow rate through the fluid control valve to drive the flow rate to a desired rate, thereby driving the sensed pressure drop across the fluid retention hood to a desired pressure drop.