Beneath the charming Provençal village of Arles lies a hidden Roman legacy, a complex network of aqueducts and waterworks that once served this bustling locale. Recent geological archaeological efforts have revealed the intricate history of this hydraulic system, primarily utilizing carbonate mineral deposits that accumulated over centuries in aqueducts, basins, and pipes.

Researchers from various institutes have collaborated on this study, which combines isotopic analysis with excavation findings to reconstruct the functioning of one of the ancient world’s most sophisticated water management systems. The story of the Arles aqueducts began in 3 BC, when Roman engineers constructed the initial aqueduct from the Alpilles hills to supply water to the city.

Nearly a century later, they added another line, diverting the original south channel to power the Barbegal mills, a monumental flour mill complex featuring 16 water wheels. This efficient redirection highlights the Romans’ engineering ingenuity as they maintained and enhanced their water supply amidst the changing needs of the city.

Unexpected findings emerged from the Baths of Constantine, where research revealed carbonate remnants embedded in fallen ceiling tiles. Isotopic analysis indicated that these deposits came from the northern aqueduct, suggesting that the water system was actively recycled and reused during the 4th century AD, continuing its operation well into late antiquity.

Additionally, isotopic correlations linked lead pipes discovered in the Rhône River to both aqueducts, confirming their role in transporting water over the river to the Trinquetaille quarter of Arles. This extensive aqueduct system exemplifies the Romans’ capacity for adapting and optimizing their infrastructure, demonstrating a commitment to sustainable water management that lasted for hundreds of years.