Dam breach analysis is essential for investigating future effects posed to human life andrnproperty by a sudden release of water to the inundation area downstream of a dam. Everyrnconstructed as well as proposed dams need to be analyzed for the possibility of dam breach tornclearly identify the extent of catastrophic effects associated with their failure. The aim of thisrnstudy is to model the dam breach at the proposed Lower Awash Dam for the development ofrnflood inundation maps used to emergency action plans. rnThe proposed dam is located in Afar National Regional State on Logia River at about onernhundred kilometers upstream from the bridge on Logia River of main road to Djibouti. Thernanalysis was performed for piping failure scenario using HEC-RAS two dimensional unsteadyrnflow modeling. The inflow hydrograph was taken as an upstream boundary condition for thernunsteady flow simulation. The model was calibrated for the flow years (1998-1999) and itsrnperformance was evaluated for the year 2001. The flood inundation and flood hazard mapsrnwere prepared by exporting the tiff raster files from RAS Mapper to ArcGIS and overlying tornArcGoogle to visualize coverage of the flood prone area due to the breach. rnThe resulting breach parameters were 146 meters breach bottom width, 1.17 hours breachrnformation time, and 0.5 breach side slope (H:V). The simulated results on HEC-RAS reachedrnpeak breach outflow discharge of 60,072 cumecs. Through model calibration close agreementrnhas been arrived between model simulated and observed rating curves at Logia gaugingrnstation. As noticed from the flood inundation and flood hazard maps an extended area in thernflat plains downstream of the dam would be affected due to the breach with a maximum floodrndepth of 21.6 m. Therefore, the flood inundation and flood hazard maps could be adopted forrnproper emergency action plans that have to be taken by stake holders.