A model has been developed for optimal reservoir operation system of Alfatha dam upstream Samerra Barrage which is considered as a strategic node in the Tigris river system in Iraq. This model is based on combining an optimization dynamic programming model with a flood routing simulation model within an optimal control framework. The predictive reservoir operation method provides optimal time operation of flood control system with incorporation of current and predicted flood wave. The model utilizes a dynamic programming with successive algorithm, interacting with hydrologic routing method. From the developed optimization model connected with the hydrologic routing model analyses of a number of predicted flood waves of Tigris river released from Mosul dam, Greater Zab and Dokan dam on the Lesser Zab have been accomplished. It was concluded that the optimal maximum operation water level in the reservoir of proposed Alfatha dam realized that all the hydraulic topographic and design constraints were 164 m.a.s.l. for the two depended predicted operation scenarios of the reservoir. While a maximum water level of 165 m.a.s.l. is the optimal operation level for the worst operation scenario of the reservoir. This operation scenario is recommended in the future hydraulic design of the Alfatha dam.