The safety and durability of concrete structures are significantly affected by cracking. This structural disorder provides a preferential path for the penetration of fluids and may accelerate the material deterioration. This study investigates the mechanical damage and permeability interactions in geomaterials subjected to compressive stress inducing cracking. The development reported here is implemented within an elasto-plastic damage model able to compute plastic dilatancy. The model assumes an initial isotropic permeability tensor which becomes anisotropic with non-isotropic expansion. The model capabilities are highlighted by simulating uniaxial and triaxial compression tests. The simulation results are compared with experimental data.