Abstract
This paper examines the importance of empirical formulas for estimating the hydraulic conductivity of non--cohesive soils, taking into account their compaction. Empirical formulas are often used in practice to quickly and cost-effectively determine hydraulic conductivity of soil. Verification of calculation of this parameter was performed for five formulas taking into account the characteristic diameters of grains and porosity. The results obtained by calculations were compared with the results of laboratory tests performed on soil samples with the same porosity coefficients (at different density index) as assumed in the calculation method. An empirical formula has been proposed to correct the hydraulic conductivity of soils obtained from the Hazen formula by taking into account the density index of a given soil.