Las «minas de agua» de Ciempozuelos (Madrid)

Abstract

Ciempozuelos is located to the south of Madrid on the Miocene gypsum formations. From old times (XIV century or former) the water supply was made mainly by means of dug galleries (denominated «mines» of water). Given the easiness of excavation of the galleries in gypsum materials and the robustness of they without lining necessity, made proliferate the «mines» and also the excavation of caves in the basements of the housings. Finally it was a crossroad of galleries, holes, mines… that extend for the underground of Ciempozuelos. The historians speculates, that Spanish name of the city mentions this proliferation of wells and mines. Actually this rich hydraulic patrimony is abandoned and in phase of deterioration due to its partial destruction. The Town Hall has undertaken archaeological and hydrogeological studies in order to improve the knowledgement of the nature and singularities of these infrastructures and later to management them properly. The hydrogeological study made, has distinguished clearly among those denominated «mines» and other types of built hollows under the urban underground. Forty six wells have been inventoried. The equipotential lines map show that the direction of the groundwater flow is mainly from the southwest toward the northeast. Thirty five chemical analysis and fifteen bacteriological samples have been made and they confirm the sulphate calcium facies with high conductivity (1,700 mS/cm) and the inadequate bacteriological quality in order to possible use in urban water supply. We recommend their use for ornamental uses, and cultural memory of the singular water supply that has persisted in the city during centuries