Taking the Songnen Plain as the research region and basing on the structural division of river water resources, the impounding models of flood water utilization are proposed. Considering the water requirement, potential impoundage and the degree of risk, two modes of the flood water utilization are developed: full impounding and partial impounding. A risk assessment method is put forward according to variation of the flood storage capacity before and after impounding water. A representative hydrological year is taken as an example to analyze the application of the model at the down-stream of the Nenjiang River. It is found that the model is very useful for the flood utilization and protection. For flood utilization, the spring drought can be relieved and the risk of impounding water is also acceptable. For flood protection, the river flood peak can be largely reduced and the impounding water can increase the river discharge at the low water period, at the same time the structure of river water resources can be improved as well.
