A systemic model for the water management in Mexico Valley

The Mexico City metropolitan area is one of the biggest urban zones of the world, not only in territorial extension but also in population. It has experienced severe water supply problems along all of its history. Such problems have been lately aggravated since its population has grown without specific plans. After a brief introduction to the problem situation, the four relevant subsystems are described, such subsystems are pluvial precipitations, aquifer exploitation, water treatment and service management. Some critical aspects are pointed out so that they can be addressed in searching for alternatives of solution. A basic input-output conceptual model is designed to have a better understanding of the current situation of the water supply system. There are two water inputs into the valley, one from rain precipitation and the other from the nearby basins and, two outputs to atmosphere and exportation respectively. Also, there are two feedback: one of them is to infiltrate water into the various aquifers of the basin and the other is to employ the runoffs. In order to reach a high quality service, it is proposed to manage the System by a central metropolitan water authority. A special emphasis is made about the importance of utilizing the enormous potential of the two big own water resources of the valley, i.e. the annual precipitation (rainwater) and the wastewater (served water).