Absent Voices and Unwarranted Presences: A Combined Multi-Approach to Mapping the Roman Hydraulic System Supplying Las Médulas Gold Mine (NW, Iberia)

This study analyses the Roman hydraulic system linked to Las Médulas gold mining complex in Northwest Iberia. The research includes a detailed mapping and assessment of the hydraulic network, which extends over 1110 km, using advanced geomatic techniques and an innovative script for tracing canals implemented in Matlab. The study reveals previously unidentified canals, improves existing cartographic representations, and addresses water sourcing and canal distribution uncertainties. It identifies 41 canals distributed between La Cabrera and El Bierzo regions, (33 and 8, respectively), with 14 canals supplying water to Las Médulas. Our study also provides evidence that this canal system had a wider purpose than simply supplying the mining works at Las Médulas. Furthermore, the findings presented here challenge established assumptions about the system’s water sources and offer new insights into how this outstanding canal system was built. Thus, this work not only provides a detailed map of the Las Médulas hydraulic system but also constitutes a model for an effective methodological approach for studying similar ancient hydraulic systems worldwide.