La canalisation souterraine de Soriech (Lattes, 34) : gestion d’une zone humide au haut Empire

The Roman occupation observed in the preventive excavation of “Les Hauts de Lattes”, near Soriech (Lattes, Hérault), is characterised by a dense network of traffic routes, but also by drainage facilities, including one in particular that crosses the excavation area over a length of nearly 300 m. This is a vaulted or, in some parts, slab-lined underground gallery, with no trace of tile concrete on the inner walls of the conduit. This structure is built at the bottom of a trench, the depth of which varies according to the topography of the land. The location of the installation trench on the surface makes it possible to reconstruct the route of the underground gallery linking the Lironde valley to the Estagnol wetland depression. The altitudes taken on the surface of the gallery invert show a slight slope from east to west and therefore a flow of water from Estagnol to the Lironde. It would therefore be a structure serving as an exit to the closed depression and to keep an important land route out of the water. This singular construction is not unique in the Roman world. It is reminiscent of the more monumental examples found in Italy, but can also be compared to the works observed in Narbonne.