Abstract This study aims to assess the abilities of inclined barrier walls (BWs) to retard the migration of contaminants through porous media. Four cases of BW arrangements were considered, including a single inclined BW (BW 1) and two adjacent BWs (BW 1 and BW 2) with different combinations of inclination ratios (i.e., I 1 = θ1 /90° and I2 = θ2 /90°). Furthermore, the effect of the distance (L) between the contamination source and BW 1 on the migration time (T) was evaluated. A numerical model (GeoStudio) containing two modules (SEEP/W and CTRAN/W) was used. The model proved its reliability to simulate contaminant migration through the porous media, where the normalized objective function values between the simulated and analytical results were 0.02 and 0.04 for the discharge of seepage and concentration of contamination, respectively. The results demonstrated that the migration time was strongly influenced by the inclination ratios of the BWs. Three-dimensional regression analysis was applied to demonstrate the combined effect of the inclination ratio, L and BW arrangements on T.