PURPOSE: To support the operation and control of a pump installed at a drainage pumping station in a river without relying on operator's experiences and intuition.

CONSTITUTION: A drainage pumping station pump operation support system has a rain gauge 7 which detects the amount of rain-fall in a river 1, a rain gauge 8 which detects the amount of rain-fall in a river 2, a water-level gauge 5 which detects water level of the river on the pump suction side, and a water- level gauge 6 which detects water level of the river on the pump discharge side. Moreover, it is provided with an off-line system which calculates water level on the pump suction and discharge sides after the current time and an on-line system which inputs rain-fall data and water-level data sequentially and automatically and controls the operation of the pump automatically based on the rain fall data detected in the past, water level data, and the situation of the operation of a drainage pump which was operated in the past. Consequently, it is possible to predict outflow of rain water from the upstream of the rivers accurately.