Geoparque Mundial UNESCO
Geoparque Villuercas > Nº41 – Mines of the Arca del Agua
This seven-century-old hydraulic work is located about 6 km. from the town of Guadalupe. It can be reached by the road from Guadalupe to Navalmoral de la Mata and then by a forest track that leaves from the hill of the Ermita del Humilladero in a westerly direction.
This hydraulic work has the following parts:
Main catchment: A network of drainage galleries or “water mines”, excavated on the southeast slope of La Villuerca, connected to the springs or “manaeros” that emerge from the fractures in the quartzite and slate rocks.
Storage: The ‘mines’ concentrate the water in vaulted deposit with point arches made of granite stones, known as the ‘Arca del Agua’ (Water Ark). Part of it is above ground but the part occupied by the water is dug into the ground.
Treatment: By decantation of the water collected in the Arca del Agua and in the adjoining “arquilla”.
Piping: Made with tongue-and-groove ceramic pipes with several factory-made “vents”, which eliminate air from the piping and regulate the water pressure to the urban centre of Guadalupe. Distribution network to the numerous fountains in the village, orchards and the Monastery of Guadalupe.
It is one of the most interesting cultural assets of Guadalupe, it was built by the Hieronymite monks taking advantage of a hydrogeological resource. It is a system for the collection, conduction and distribution of drinking water by gravity for the Monastery and village of Guadalupe, known as the Arca del Agua (Water Ark). It dates back to 1350 and is still in operation today with slight modifications to its original structure.
The materials that make up the Sierra de la Villuerca are mainly layers of sandstone and quartzite (Armorican Quartzite), which are highly fractured and have excellent permeability, capturing the water from rainfall and the mountain ranges. On the slopes of this mountain range and, more specifically, next to the Viejas syncline, we find the “Los Hollicios” rocky outcrops, formed by large angular fragments of quartzite which also have a high permeability, with water infiltrating through the numerous gaps between these rocky blocks. The water accumulated in the Armorican Quartzite is channelled through the synclinal structure and emerges in the wide areas of contact with the Ediacaran materials (Ibor Group), consisting mainly of shales and sandstones with low permeability. The water infiltrating through the fractures in all these materials is collected by means of underground excavations known as collector galleries or water mines built into the mountainside.
Occasionally, the underground water can flow out on its own, creating springs or hillside sources, known in the region as “bohonales” or “trampales”, such as those found near the Arca del Agua mines. Some of these springs were also “captured” to supply the town of Guadalupe and its Royal Monastery and are the ones that mark the source of the Guadalupe river (See Geosite 14).
