Abstarct: In the last years a lot of problems about safety and stability of diversion dams and seepage through dam foundation has been created. Also occurrence of piping at the downstream of diversion dams and destruction of the bed is considerable. Construction of cut off andconcrete apron under the water structures are the effective alternatives in order to control of seepage discharge andpiping. In this study using the experimental model for different positions of cut off and apron at several upstream heads, outlet gradient, seepage discharge and uplift forces were investigated. In order to verify numerical results software of Geo studio 2007 (seep/w) was used. Result showed that using the downstream apron compare to upstream apron was more appropriate to control seepage. Also apron with cut off at the downstream and upstream showed the best result in control of the outlet gradient, seepage discharge and uplift force so that at the head of 52cm, relative error for this model was 2% and 8%, respectively. In experimental model, the seepage discharge for the main model, model apron and model with cut off was measured about 302,175 and 222, respectively. Simulation results of the uplift force for the model with apron and foundation cut off and the model with apron and cut off at the end had relative error about 8%. Result showed that numerical model had good agreement with experimental model so that the relative error was less than -+10%. According to results of this study in order to simulate moving of water through the soil with acceptable precision can use the seep/w software.