Abstract: A plurality of relatively large, high capacity, high head, pumps disposed in parallel in the basement of a building provide water under pressure throughout the water pipes in a high rise building. Pressurestatic switch means controls the operation of these main pumps. A small, low capacity, high head auxiliary pump of an auxiliary booster system in the upper regions of the building supplies water to an accumulator tank in the auxiliary system from the water pipes so that during periods of low demand, such as at night and on weekends, the operation of the main pumps will be minimized. A control assembly including a timer and pressurestatic limit switches in the auxiliary control system dictates when the auxiliary pump is actuated and shut off and when the accumulator tank is opened to the water pipes.