A drain related to the second phase of the complex, after the abandonment of the side street that bounds the complex on the east and the abandonment spoliation of much of the ashlar masonry. It seems to be closely associated with the concrete construction to the south, along the main trunk road. Based on the fact that wall 5413 is faced to a heigh of almost two metres along the retaining wall (which presumably originally continued south to join wall 5386)seems to have been cut into layers of soil (dump), this drain was probably covered/enclosed, and may have been at least partly below ground level. South of wall 5392, it is clearly associated with the other water features of the "eastern corridor".