Upon excavation in July 2018, it does indeed appear that the drain was originally in phase with ashlar blocks 7197, and that these blocks represented the original northern limit of the drain. Where the drain met the blocks, the walls of the drain were built of flatly laid courses of tile and mortar, rather than broken tiles stood on their sides.

This drain, related to a later phase of reorganization of the space between ashlar walls 7108 and 7038 is the northern continuation in Room 4 of the drain that begins in the center of Room 5 (7201), and which there may have been related to some kind of basin feature. It passes between the two rooms beneath threshold 7185.