Analyse de surface d'un réseau souterrain : le système d'évacuation collectif des eaux à Ostie
Résumé
The evacuation systems for six settlements in southern Gaul were studied in great detail as part of a thesis exploring the topic of the sewage network in an urban context in Gallia Narbonensis.
In order to better understand certain elements of poorly preserved infrastructures in this province, we have compared them with structures observed in the ancient city of Ostia which has been subjected to extensive excavation work and whose ruins are remarkably well preserved.
Unfortunately, it quickly proved to be difficult to study Ostia’s evacuation system without conducting an archaeological excavation, as the research dedicated to this issue is very sparse. Due to time constraints, taking on such a large project was not feasible within the context of a doctorate.
In the end, the solution to examine the subterranean hydraulic network was discovered on the street surfaces. Gemma C.M. Jansen had already highlighted the presence of ground markers. These markers indicate the presence of public sewers under the streets (Jansen, 2002, p. 46-47 ). She even created several maps, but it turns out that certain structures, while visible on location, are not listed or classified. In addition, the recreation of the sewer system suggested by Gemma C.M. is not supported by any kind of evidence. In order to create a detailed map of these surface structures, it was necessary to completely start over the study in question.
It is now possible to propose a historical reconstruction of Ostia’s collective sewer system thanks to prospection work carried out with the assistance of a GPS in February 2017 on these surface structures. This works allows us to examine how these different components could have impacted the setup of the city’s collective network. The systematic review of these surface structures also makes it possible to establish a typology based on the models observed in Narbonese Gaul.