Water flowed into the castellum divisorium, a distribution station on the highest point of the city near the Vesuvian gate. Due to significant height differences which caused undesirable pressure variations in the water system, a series of water towers were constructed to regulate pressures in different districts within the city.
Water flowed into the central water hub, situated at the city's highest point near the Vesuvian gate. As a result of considerable elevation differences affecting the water system's performance, elevated storage tanks were erected to regulate and stabilize water pressures across various city sectors.