The seepage problems from open channels constitute one of the major problems facing ministry of water recourses and irrigation. Many solutions are suggested to solve the problem of seepage from channels, some solution by covering the bottom of the channel with concrete or asphalt, other solution by the use of sheet piles. The current study aims to control the seepage losses by using clay core to decrease the seepage amount. The clay core can decrease the seepage rate by increasing the length of seepage line. Since the seepage lines are inclined, the most effective position of clay core has been determined by studying the effect of vertical clay core with different penetration depths in the soil and different head difference. Similarly studying the seepage rate for different positions of the core clay and constant  pressure difference (ΔH) has been evaluated