Water Storage and Distribution in the City

Nearly 100 cisterns are known from archaeological and literary sources for Constantinople, ranging from small private establishments, to enormous open-air reservoirs. Çeçen (1996a) estimates that the total water storage capacity of the city's cisterns and reservoirs was between 800.000-900.000 m3.

Two of the reservoirs (Aetius: 197,000 m3; Aspar: 220,000 m3) were established in the early 5th century on highpoints ( c. 60m.) in the city's suburbs. A third (Mocius: 250,000 m3) was added in the early 6th century on the seventh hill of the city. In part the reservoirs seem to demonstrate the greater concern for security witnessed by the near-contemporary Theodosian Walls, since they are located inside the defensive circuit. Another reservoir however, the Fildami or "Elephant's Stables" is known to the south-west of the city, close to the assembly point of the Byzantine campaign armies at the Hebdomen. Its role appears to have been fundamentally to provide water for the substantial palace that developed in the Hebdomon in late antiquity. No aqueduct has been identified leading to this extra-mural reservoir although it seems more likely to have been supplied from known sources to the north of the Hebdomen, than by the long-distance line. In practice it remains unclear how any of the reservoirs worked within the system as a whole. However the piezometric towers (aqua castellae / control and regulation towers) evidenced in the Mocius and Fildami reservoirs demonstrate their function not only as large capacity storage tanks but also as control points in the distribution network of the city.

It could be argued that the three intra-mural reservoirs were associated with the expansion of the water supply system that took place probably in the 5th century. The new broad channel would have provided a greatly increased discharge to the city, perhaps creating the opportunity to store water on such a large scale.