The water-supply system in Roman Pompeii

Abstract: This study focusses on the urban infrastructure for water supply in Roman Pompeii. The water distribution network of lead pipes was constructed inside the city walls, at the time when the city was connected to an aqueduct. Life for the Pompeiians changed considerably when aqueduct water started running continuously in street fountains all around the city. The study is based on previous research and on my own investigations and measurements on site in connection with the Swedish Pompeii Project. The thesis presents a new interpretation of the main water system, in specific, the interconnection of the water towers. Three main water pipelines were connected from a distributor building, Castellum Aquae, located at the highest level in the city, and supplied water to the top containers on at least fourteen water towers. The main water system worked on the principle that water could flow down from the top container of one water tower to the next provided that this was located at a lower level. Investigations and measurements of the vertical grooves on the sides of the water towers support my conclusion that two of the water towers were designed to supply water to two public baths. Three of the water towers were built with a groove for a connection to other water towers in the not yet excavated parts of the city. The study also presents a small part of the water distribution for public and private use. The design of individual pipes from the top container of water towers to all street fountains, public baths, houses and workshops was based not only on the shortest distance between water tower and water user, but also on the head between the level of the top container and the level of the water user. It is argued in the study that the planning of the water infrastructure was a complex procedure. The design engineer in antiquity had to consider changes in the operation of the system and changes in the demand from water users.