Sizing of the cells of the units is important for constructional and aesthetic reasons. Where a gabion facing is required with a sloping face, it can be used with the face inclined and the rear face vertical. It may be possible to design this type of cladding as an effectively free standing wall not physically tied back to the main structure. Due to the nature of discharge of the outfalls, consideration of the turbulent flow conditions occurring is required when determining the depth of gabion protection. The design considerations are similar to those encountered in culverts and around bridge piers.