Sheet piles are necessary with hydraulic structures as seepage cut-off to reduce the seepage. In this research, the computational work methodology was followed by building a numerical model using Geo-Studio program to check the efficiency of using concrete sheet piles as a cut-off or reducer for seepage with time if the sheet piles facing the drawdown technique. Al-Kifil regulator was chosen as a case study, an accurate model was built with a help of observed reading of the measuring devices, which was satisfactory and helped in checking the sheet piles efficiency. Through the study, three scenarios were adopted (with and without) drawdown technique, it was found that at the short time there's no effect of the drawdown technique on the Factor of Safety Against Uplift Pressure (F.O.S.(uplift)) while at a long time (from 1 month to 30 years) the F.O.S.(uplift) will increased to value less than that case of applying drawdown technique, which mean that the drawdown will reduce the F.O.S.(uplift) about (0.5%), the drawdown technique has effect on sheet pile efficiency also were the sheet pile efficiency was reduced about 14% at the short time (along the first month) but, at a long time (along 30 years) the sheet pile efficiency rise again to reach 99.9% of its original efficiency before drawdown. So drawdown time should be checked to avoid the reduction of the sheet pile efficiency.
