The saturation zone encompasses the area below ground in which all interconnected openings within the geologic medium are completely filled with water . Once water passes through this zone the after moves sideways. The saturation zone is divides into two subzones: the phreatic zone and the capillary fringe.Water within the phreatic zone will readily flow out of the pores while the negative pressures within the capillary fringe tightly hold the water in place.