You sure? The relative height of a water tower and the faucet from which we draw water does make a difference in the speed with which the water flows. Higher pressure at the lower location means more force acting on a a unit volume of water at the nozzle, hence more acceleration, greater speed, more kinetic energy. The greater speed translates into greater flow so the water level in the reservoir drops more quickly, transferring more potential energy per unit time.
I may be reading OP's (less than perfectly clear) question differently than you. If so... never mind.