PROBLEM TO BE SOLVED: To estimate the cause, place, and scale of abnormality of water supply facilities by speedily grasping the abnormality in real time at a central monitoring center without visiting a site. SOLUTION: Water gauges 10 are installed along a water channel 3, and measured water level measurement data L1, L2 are transmitted to a center server 14 through transmitter receivers 12. A hydraulic analysis model is created based upon information on the actual water channel. Abnormal contrast data having water surface shapes patterned by kinds of abnormal phenomena based upon the hydraulic analysis model and normal contrast data having water surface shape patterned at normal time are found, and those found data are input to a storage part of the center server 14. The center server 14 determines whether there is abnormality by comparing and contrasting the gathered water level measurement data L1, L2 with the abnormal contrast data and normal contrast data input to the storage part, and displays the cau
