Strategic database for the diagnosis and prognosis of hydrogeological conditions in a highly populated volcanic watershed in Central Mexico

Intensive groundwater extraction in Central Mexico, driven by the increasing demand from population growth, exerts significant pressure on the hydrogeological system. This has led to sustained declines in piezometric levels and a deterioration of the chemical quality of the water produced by wells all around the entire watershed. Adequate watershed management requires comprehensive information to understand its behavior.In this regard, the objective of this work is to compile hydrogeological data for a volcanic watershed that hosts one of the world's largest cities: the Basin of Mexico. The methodology consisted of consulting, collecting, and processing various databases from the National Water Commission (CONAGUA), the National Autonomous University of Mexico (UNAM), and various technical studies.The result is a groundwater compendium with data from 1960 to 2022, providing a technical analysis of changes in water levels and chemical composition associated with groundwater use. Additionally, it contains physiographic, edaphological, geological, and climatological information, along with lithological columns, isotopic, hydrogeological, and hydrogeochemical data. It also includes the locations of wastewater discharge sites, treatment and drinking water plants, deep wells, protected natural areas, the piezometric monitoring network, the delimitation of hydrological-administrative regions, administrative aquifer boundaries, and the delimitation of the regional flow system. Furthermore, all the data is available for visualization with a Geographic Information System (GIS).Finally, establishing a database and a subsequent diagnosis of hydrogeological information is of vital importance. It allows for the identification of areas of opportunity to improve our knowledge of the watershed and enables the proposal and definition of necessary works, such as the construction of piezometers, water level monitoring, and chemical and isotopic analyses, among others. All these elements are highly valuable for decision-making regarding management, infrastructure construction, and monitoring.