Water Troubles Cause Mexico City to Sink

Mexico City is sinking — in some areas, by as much as a foot a year, and altogether by about 30 feet over the past century. The sprawling, smoggy metropolis — more than double the size of greater London — has been depleting the aquifer on which it was built, and that aquifer is now collapsing. To meet current demand for 10.5 million gallons of water a day, the city pumps water from two nearby river basins at a cost of some $50,000 a day for water rights alone. The sinking city also puts massive stress on the network of water distribution and drainage systems that spiderweb beneath it, which routinely crack, leading to a loss of around 40 percent of potable water. The city must also now pump its sewage uphill before it can be drained into the Gulf of Mexico. The smog-shrouded city’s water troubles are a sign of things to come for the world’s metastasizing megacities. According to UNESCO, 7 billion people from 60 countries could face water shortages by 2050.