While working up preliminary study of MAP's hyrdraulic system and reviewing final phasing, interpretations on this drain have changed. Inititally, excavators identified two separate drains. A ditch filled with stone & tiles covering a lower/earlier stone channel. It is not believed that these drains are part of the same french drain construction: a ~1m-wide ditch was dug (20103 = 20109 = 20031), cutting the cocciopesto surface of Room D as well as the back wall (20018) and conduit (20030 = 20038) north of the backwall. Then a stone channel was built at the bottom (20105) covered with large stones. Finall the ditch was backfilled with stones and tiles (20111 = 20102 = 20032) to create a soakaway that directed water into the channel. This drain was built after the winery went out of use but before the fire event since the drain is covered with collapsed wall construction material (20099).

Fill includes soil with frequent tile fragments, of all sizes, and stone. Were these tiles part of a drain lining or covering? This feature is the continuation of cut 20031 & fill 20032 from the Northern trench of Area 20000, cutting through Wall 20018, thus post-dating the Opus Reticulatum walls. This feature was most likely used for drainage as it mirrors simple drains used in farming today. SU 20102/20103 may be on the same alignment as similar drain found in 13000, 11000, and 15000.