Interdisciplinary Investigation Approach to Analyse Historical Water Infrastructures and Urban Transformations: The Case Study of the Grabiglioni in the Sassi of Matera, Italy

The Sassi of Matera represent an emblematic example of a resilient historical city, where the structure of the places reveals the close link between the historical urban fabric, water resources and climate. The inhabitants of the ancient settlement, which was placed on the slopes of the Gravina Torrent and around the Grabiglioni streams, produced processes of urbanization that respecting the morphological characteristics ensure the supply of the resources necessary for the subsistence. In the historical city, the Grabiglioni, also called Fossi, allowed to transport the surface runoff into Gravina Torrent, ensuring the ecosystem balance and avoiding critical conditions such as uncontrolled surface runoff and flooding within the two urban districts of Sasso Barisano and Sasso Caveoso. But during the first decades of the 20th century, the Fossi were adapted and used as collectors for sewage and surface drainage, through the construction of roofs, which irreversibly transformed the urban landscape of the Sassi. In fact, above these roofs the main access routes to the neighbourhoods were located, which from this moment will be chronically affected by rapid surface runoff. This study describes the characteristic configurations assumed by the historical water infrastracture of the Grabiglione Barisano and the Grabiglione Caveoso over time and their operating modes, analyzing materials and construction techniques through the study of historical documentation. The proposed analysis methodology highlights the relationships between the transformations produced on the Fossi (Fosso Barisano and Fosso Caveoso) and the effects of these transformations on the Sassi. This method can be applied to analyze other historical water infrastructures, allowing today’s urban planning approaches to acquire from the historical heritage essential knowledge to guide water sensitive processes for the sustainable development of future smart cities.