Worries concerning the possibility of the dam failure due to the seepages under the foundation of Mosul Dam during its construction and operation phases enhanced the application of several dam failure models on Mosul Dam case. All the applied models gave similar results. It was noticed through the models that the wave in case of the dam failure will have a height of 54m and the discharge will be of the order of 551000 m3/sec. This wave will reach the capital city of Iraq “Baghdad” after about 38 hours. The discharge of the River Tigris at Baghdad will be 46000m3/sec and the height of the wave will reach 4m. The propagation of the wave along this distance will cause a catastrophe. About 500000 civilians will die in addition to the unbelievable damage that will be caused to the infrastructure of the country.