The earth dams, formed to create a storage space for mining waste disposal are called the flotation dams. Incidents at these dams are not uncommon, and as a result, the dam can ultimately collapse and form a flood wave. The simulation of a dam breach and flood wave propagation is aimed to determine the flooding boundaries and the time of arrival the flood wave to ensure the precautionary measures, alerts, and notifications. This study presents a 2D HEC-RAS model was used for the flood wave propagation. Attention will be focused on defining the input parameters when creating the model.