Water-powered industries played a crucial role in the development of ancient economies, as waterwheels were likely the first mechanical energy source operated by humans. Although many of these infrastructures are now abandoned, they hold significant potential for energy generation, tourism, cultural and educational purposes. This paper presents a methodology for locating and cataloguing historical water-powered industries using various information sources. The two primary sources are twentieth century historical maps and fluvial itineraries, which detail the locations of water-powered industries along the main rivers and tributaries of Spain during the nineteenth century. These sources complement each other, and together with previous studies, historical aerial images, and oral testimonies, they have enabled the creation of a database of 483 historical water-powered industries within a 10,306 km2 territory in the Spanish province of Soria. The data were managed using QGIS software, which also organized field trips for cataloguing these infrastructures. Among the identified typologies, flour watermills account for 82% of the structures, followed by power plants, sawmills, fulling mills, and other water-powered factories. Field visits have further helped identify industries with high potential, as well as uncover elements of significant heritage value, including waterwheels, old turbines, machinery, weirs, and canals.
