Historical failure of dams and then impact on the environment created immense disaster in terms of loss of human life and property. A disaster is associated with risk and therefore needs a thorough investigation for its possible outcomes and safeguards. Therefore, study of risk associated with each dam is becoming an important activity to prevent and mitigate the consequences of its failure. To understand the dam break process, many researchers have investigated the work by using distorted physical model, numerical simulations or experimental coupled with numerical based approaches. To quantify the risk associated with dam break, one needs to understand the breaching process that leads to predict breaching parameters. This research is focused on three main objectives, empirical equations are proposed for estimation of breach parameters and peak outflows by using data of past dam failures. It is known fact that the resultant flooding at the downstream reaches due to an overtopping failure of the earthen dam is reliant on breach formation process and the erosion rate of compacted soil. Therefore, the second objective is to carry out the overtopping failure of 22 embankments that are experimentally investigated that are constructed with different soil properties, compaction moisture content and compaction energy. The purpose is to understand, how these breach parameters are affected by the change of soil properties, compaction moisture content and compaction energy. The final breach shape and parameters recorded in the experiments show remarkable change for each failure. The results testify a high correlation between compaction moisture content with the erosion process. Also, the effect of embankment cracks on over topping breach failure is studied. It is seen that embankments with large dry density erode faster as compared to the embankment with low dry density because of the developments of deep and long cracks in the former. Further, MIKE 11 (1-D) hydrodynamic model