Mexico City is sinking, running out of water: How can it be saved?

The city faces ‘Day Zero’ as aquifers drain and pipes break. Meanwhile, costly workarounds don’t fix the real problem.

Mexico City, Mexico – Walking through Mexico City’s historic Zocalo district, Dario Solano-Rojas points to signs of a subterranean catastrophe that is under way.

The roads are uneven in the city’s central plaza, the streets and walkways are sloped and twisting. Many building foundations have sunk dramatically while others have a visible lean, resulting in cracks in the surrounding pavement. Two of the city’s most iconic structures – The Palacio de Bellas Artes and the Metropolitan Cathedral (built from the stones of the Aztec temple that once stood there) – seem to be disappearing into the earth.

Inside the cathedral, Solano-Rojas, a professor of geological engineering at the National Autonomous University of Mexico, points to a glass-encased box connected to the ceiling by a taut wire. At the centre of the nave hangs a heavily-weighted point, which charts a line indicating how the cathedral has shifted unevenly over the centuries, with the worst-impacted section dropping by some 2.5 metres (8.2 feet).

Mexico City is sinking, as are its greatest monuments. Parts of the city of nearly 9 million people are descending into the earth by as much as 40cm (15 inches) annually – all driven by a deepening water crisis with roots that go back 500 years, and that reveals itself today in stunning ironies.

One of Mexico City’s most renowned attractions, the canals of Xochimilco, with their lush lagoons and colourfully decorated boats, date back to the precolonial lake that once satiated the city’s thirst. Today, its adjacent neighbourhoods have run out of water.