The goal of the research is estimation of the energy efficiency improvement potential when the proportional pressure control mode is used at the second stage pumping stations in public water supply systems. For this reason, a large number of energy cost analyses have been made for different centrifugal pumps and regression equations with coefficients of determination have been derived. As the result, the savings’ potential of energy consumption has been defined, if proportional pressure is used instead of constant pressure. The decrease of water leakage has also been determined when the proportional pressure control mode is applied.