This study investigates the effects of berm properties on a moderate height earthen dam stability. The impacts of different berm heights, numbers and widths on the safety of the Hancagiz Dam are determined by analyzing the seepage through the dam and the slopes' stability under steady-state, rapid fill and rapid drawdown conditions with the finite-element method. The results showed that increasing the upstream berm height, number, or width of berms provides higher safety factors for the upstream slope. However, an excessive increase in the berm height is seen to cause a lower safety factor. Increasing the berm number is found to give maximum stability among all options. Any change made on the upstream berm does not affect the safety of the downstream slope.