Numerical failure simulations of Kestel dam were performed under different scenarios. The numerical model employed was developed by Fread, D.L., and called DAMBRK. In the simulations, it was assumed that a breaching started, within the dam body soon after the maximum possible flood hydrograph entered the dam reservoir and caused the water to spill over the dam crest due to insufficient capacity of the spillway. Peak flood discharges, peak flood elevations and flood arrival times at preselected six cross-sections downstream of the dam were determined. Regions affected most adversely were found to be those closest to the dam site