After the reservoirs were back in use thanks to Constantine V's repairs to the Valens-line in 766, the Reservoir of Mocius is attested in several sources.

The first literary mention of this Reservoir is curiously enough only in the 10th century (Patria 3.84). In the same century, Constantine VII's De insidiis mentions that emperors held receptions near the church of St Mokios (next to the reservoir), and that before going to this church, emperors passed "the aqueuct in which water flows". Crow et al., 2008, p. 238 comment that this is likely not a topographical confused account, but referring to an actual aqueduct, adjacent related to the Reservoir of Mocius.

Mesarites in the 13th century reports that all "four heads of rivers" still supplied Constantinople. These four heads have been identified as Aspar, Aelius, Mocius and possibly Bonus. This would imply that by Mesarites' time, the reservoir of Mocius was filled with water.

The late 15th century list Codex Matritensis Graecus lists the reservoir "of Mukusia"; the name of the reservoir was thus preserved (albeit in altered form), in contrast to the other cisterns listed which received different names.

It is only with Gilles in the mid-16th century that it is reported that the Reservoir of Mocius had been turned into a garden, devoid of water.