The Mexico Basin (MB) includes the nation’s capital Mexico City, and is one of the most important metropolitan areas in the country representing the largest urban area in North America and the fifth largest in the world. A population currently reaching 22 million with constantly increasing water demands has resulted in the overexploitation of groundwater resources in the basin with changes in hydrological conditions over centuries. The urban, agriculture and industry practices on this area heavily rely on the basin’s aquifer groundwater resources to meet water demands; forecasts of expanding the metropolitan area will result in continued groundwater use with additional overexploitation. Historic and recent groundwater pumping has caused decrease in groundwater storage, significant declining groundwater levels, accelerating aquitard compaction translated in land subsidence, which is by now mostly permanent. The subsidence of the land has caused operational, maintenance, and construction-design problems for water delivery and flood control. Additional problems, which must be considered and monitored, are the changes in groundwater quality. Management and evaluation of this precious resource requires a detailed understanding of the aquifer dynamics along and within its natural boundaries. An integrated conceptual model of the Mexico Basin Aquifer (MBA) was developed for the first time based on literature, three-dimensional geologic and hydrogeological models, processes of hydro-mechanical behavior and geochemistry. This conceptual model updates and improves an existing numerical model, which is used as a guide to assessing the current and historical aquifer behavior and to provide aquifer sustainable evaluation through indicators. The model proposed in this study could be use in the evaluation of management plans designed to mitigate adverse impacts due to regional subsidence while also optimizing groundwater demands. This knowledge is critical to understanding the long-term sustainability of this resource under future land use and population growth in the MB. This work attempts to address the following issues and questions: What is the state of groundwater conditions in Mexico City after 100 years of increased pumping? What is the status of ground deformation (subsidence)? Is current groundwater use sustainable? What are the lessons learned and what is next?