Good practices for the management of undesirable waters in the Roman city: Some case studies. Le buone pratiche per la gestione delle acque indesiderabili nella città romana: alcuni casi di studio En It

Résumé En

The problems of hydraulic risk in Roman cities are almost always related to the proximity of a water-way or even the sea. In fact, cities had to defend themselves not only from the waters that ran through or lapped at them, but also from what we might call ‘internal waters,’ and especially wastewater. In order to protect against this undoubtedly less obvious, but no less dangerous, hydraulic risk, it was necessary for there to be continuous and careful maintenance of the sewer network and also for this network to be designed in such a way as to minimize risk through certain expedients (division into several subsystems, in-take of running water from the aqueduct or canals), as well as a perfect correspondence with the physical geography of the city. The adherence to physical geography then means that where the sewer system has been studied as a whole, its structure also provides useful insights to better understand the original design of the city and the interventions that accompanied its birth and formation. The study of the evacuation systems for clear wastewater has also, in some cases, highlighted an aspect that is normally ignored, namely that of the eventual recycling of this water, certainly not for potable uses, but for other purposes. For example, this is what must have happened to the clear waters of the baths in the Roman city of Ostra in the Marche, and has also been recognized in other centers, such as in Cassinomagus, today’s Chassenon, in south-eastern France. Run-off water also ended up in the sewers, but only partially. The management of these waters is a little-studied but important aspect, because, as some texts testify, they could cause inconveniences to daily life.