Geo-Hydrological Characteristics that Contributed to the Choice and Configuration of the Ancient Roman Aqueduct Aqua Augusta from Serino Springs

The Augustan Aqueduct, built between 33 and 12 BC at the command of Augustus and designed by Marcus Vipsanio Agrippa, stands as one of the most remarkable hydraulic engineering feats of the Roman era. The main route of the aqueduct extends over 100 km, starting from the caput aquae, represented by the Acquaro-Pelosi springs located at the foot of the Terminio karst massif, near the village of Serino (Campania region) and ending at Castellum Aquae, which corresponds to the Piscina Mirabilis in Bacoli, near Neapolis. Hydrogeological and hydrological features have been analyzed to reconstruct the rationale behind the selection of the aqueduct’s water sources: flow rate, ground level, and quality of the karst waters of the Serino springs best met the supply requirements. These characteristics, and others of historical and archaeological nature, suggest that the Augustan Aqueduct had a hydraulic connection with the Sannitico Aqueduct, also fed by Serino springs. The Sannitico Aqueduct fed the town of Benevento towards Nord, and it is believed to have been built in the first century AD. As shown by this study, both aqueduct systems could be part of a unique and great hydraulic system, built in the 1st century BC to supply areas of great residential importance (cities and patrician villas) or military importance (Miseno harbor and Benevento). The several studies available on the Augustan Aqueduct primarily focus on archaeological, architectural, and engineering aspects and less on hydrogeological aspects. In this paper we highlight that the hydrogeological perspective represents a key to understand the rationale behind the selection of the water sources feeding both aqueducts, built probably at the same time, and their interconnection.