Water footprint sustainability at valley of Mexico's basin

This paper estimates the water footprint (fresh-water consumption) at Valley of Mexico 's Basin (CVM in Spanish). This region has the biggest population and economic activity of Mexico. The methodology incorporates virtual water to the engineering scheme based on quantifying extraction and water use, and which more accurately measures the stress faced by water resources due to the enormous water consumption in the basin. The estimated water footprint is 3 895.59 hm(3) of annual fresh water in 2015, making evident the water requirements of the residents of the CVM. Hence, the footprint is equivalent to the average annual water catchment at the Falcon Dam (Tamaulipas, northern Mexico), which accounts for its enormous resource requirement. Supplying such a level of water consumption has required the creation of a complicated and expensive supply engineering and overexploitation of not only own but also and external water resources. More precisely, when 202 m(3) of water are consumed in the CVM, 100 m(3) are explained by renewable water and 102 m(3) of non-renewable water. Of this last value, 39.3 m(3) come from overexploited aquifers in the same basin; 32.8 m(3) from the import of overexploited basins, and 30.4 m(3) is virtual water imported via the foreign trade of the basin. Finally, this composition shows that half of the consumption is based on the predatory extraction of water resources. This is received in the sustainability index of 202%, which is recorded by the water footprint in the CVM and is a value that indicates its extreme fragility to maintain itself over time.