Mexico City’s subsidence puts buildings at risk

Every year, the lacustrian plains of Mexico City report a sinking of between 8 and 12 centimeters due to excessive water extraction in nearby aquifers, which has catastrophic effects on the city’s infrastructure, according to Efraín Ovando Shelley, an investigator from the National Autonomous University of Mexico (UNAM) .

The specialist from the Engineering Institute pointed out that “Mexico City is exposed to many long-term risks; one of them is the regional sinking that is happening at a slow yet constant pace, at least since the middle of the 19th century .”

He pointed out that said process “is causing critical problems in many parts of the city, since it contributes to the formation of cracks and flaws in the urban infrastructure and traffic system, as well as the architectural and artistic heritage of Mexico’s capital.”

Ovando Shelley explained that natural phenomena such as earthquakes , which last only a few seconds and a minute at most, often have catastrophic consequences , “but the land subsidence is a slow acting disaster as well. Its speed can vary depending on the specific area, and it could even be minimal, but it is also permanent.”

The expert pointed out that Mexico City’s historical center “is one of the most affected zones , since several buildings have been exposed to the subsidence for a long time now, though all the basin has taken damage in one way or another.”

Furthermore, he reminded that a great deal of the Mexican capital is built on what was once a lake (with soft and voluble clays), “which is why when water is extracted from underground, the subsoil is easily deformed, resulting in subsidence.”

The expert stated that there is no short-term solution to stop this phenomenon , but a plausible mid to long-term solution would be to stop tapping water aquifers.

Another option would be to build a parallel drainage network that picks up rainwater, and another one for waste water. He claimed that it was technically possible to treat rainwater and re-inject it into the subsoil.

The environmental impact of tezontle extraction in New Mexico City Airport

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