In the conditions of severe climatic changes that are sweeping the world now, causing many problems, of which high surface water levels, torrential rains and floods are among the most dangerous phenomena. Since dams are the most engineering and structural protection means that engineers resort to, to protect against these dangers in such circumstances, not to mention the other important uses of dams such as storing water for irrigation purposes, generating electricity, feeding the underground reservoir, or diverting flow paths for any engineering purpose. Dams are usually classified on the basis of several considerations, including solid dams of different types, and flexible dams. Flexible dams, which are sometimes called earth dams, are of a special nature as they consist mainly of loose materials of a special porous nature and different ratios of interspaces that allow water to pass through them and penetrate the dam body in different proportions, which, if not prevented or avoided, may lead to the collapse of the dam body. In the present study a numerical analysis of seepage through zoned earthen dams is introduced, as they are the most popular type of flexible dams, to clarify the behavior of the streamlines of the seepage water through the body of such type of dams with different types of used soil of filling materials. Decreasing the relative permeability coefficient between the inner and transition zones up to 0.001 caused a significant decrease in the different seepage properties, after that, the effect was minor.