Abstract: Only statistical flood information is employed in the traditional control of the limited elevation of a reservoir in the flood season.In this case,the reservoir is controlled at a relatively low elevation in order to prevent from its design flood every moment during the whole flood season.In this way,many reservoirs,especially in northern part of China,have to spill lot of surplus water when floods occur,while there is little inflow to those reservoirs after the flood season when they are allowed to store water to a relatively high elevation.In order to use more flood resources,a new idea and its syntheric inference models are proposed in this paper to control the limited elevation of a reservoir dynamically during the flood season according to rainfall-runoff and shortterm (24-h) rainfall forecast in the reservoir basin.At the present developmental level of rainfall-runoff and short-term rainfall forecast,it is possible to predict what floods will occur in the next few days.Furthermore,the limited elevation of the reservoir is dynamically controlled by means of a set of synthetic inference model.At the same time,when the design flood happens,we must have compensation measures to ensure the reservoir's safety in case of forecast errors.