Design of irrigation and drainage networks requires accurate estimation of relevant parameters, which is made possible using new estimation methods. Important parameters useful in determining drain spacing include the depth of the hardpan and the hydraulic conductivity of the area. New interpolation methods based on geostatistics take into account spatial variations in variables, thereby reducing the inaccuracies of traditional methods. Therefore, this study uses geostatistical and Thiessen's polygon methods, which is a common method in drainage design, to estimate hardpan depth and hydraulic conductivity parameters for estimating drainage distance. The results show that simple kriging and universal kriging methods with determination coefficients of 0.83 and 0.89 and root mean square errors of 0.26 and 2.67 (meters) achieve the best results for determining the depth and permeability of impermeable layers, respectively. Also, the best fitted variogram respectively were calculated as an exponential variogram with zero nugget effect and 1.37 sill and a spherical variogram with a sill of 0.027 and 0.003 nugget effect. showed the strength of the spatial structure of the area and the full impact of the structured component on the variogram model of the parameters. Also, the results showed that the distance of drains is uniform and non-uniform condition at different depths of the installation of drains, in kiriging method were calculated less than thiessen method. And with taking into account areas with hydraulic conductivity of more than one meter per day, the difference between the two methods in estimating the distance of the drains increased to 11%.