The Castellum Aquae was ancient Pompeii’s principal water-distribution point. It stands near Vesuvius Gate at the highest point in the city, approximately 42 metres above sea level.
Water reached Pompeii through a branch of the Augustan aqueduct from Serino, in the area of the modern province of Avellino. Once inside the castellum, it was collected in a large basin before being distributed through the urban water network.
A system of sluice gates and low baffle walls regulated the flow within the structure. The water left through three pipes set at different heights and, using the natural gradient of the terrain, reached the various parts of the city. Wooden wedges could be used to close the pipes whenever the supply needed to be reduced or interrupted.
The system fed public fountains, buildings such as the baths and numerous private consumers. Pompeii’s water network is one of the most instructive examples of the sophistication achieved by Roman hydraulic engineering.
The Castellum Aquae was damaged by the earthquake of AD 62. According to the archaeological evidence, the system does not appear to have been fully operational when the eruption occurred in AD 79. The building was brought to light in 1902.
