Steps added to monument in Mexico City

Fourteen steps have been added at the base of the Angel of Independence in Mexico City to keep the monument accessible as the ground beneath it sinks. The ground in certain areas of the city is sinking by about 2 centimeters per month, mainly because water is being removed from underground reservoirs, which causes the clay beneath the city to compress.

Monument's history and adaptation

The Angel of Independence, a 35-meter column, was inaugurated in 1910 to celebrate the centenary of Mexico's independence. It was originally at street level, but as the ground has sunk, the street level has dropped, requiring the addition of steps to maintain access to the monument.

Satellite data reveals subsidence

The NISAR satellite, launched by NASA and the Indian Space Research Organisation in July 2025, recorded subsidence of about 2 centimeters per month in areas including the airport and the base of the Angel between October 2025 and January 2026. This amounts to over 24 centimeters of subsidence per year, as detected by the satellite's radar technology.

Mexico City's geological challenges

Mexico City is built on the site of the ancient Lake of Tenochtitlan, the Aztec capital, and its 22 million residents rely on an aquifer for about 60 percent of their drinking water. The extraction of water from this aquifer causes the clay and volcanic soils beneath the city to compact, leading to ground sinking. Geologists from the National Autonomous University of Mexico (UNAM) describe this extraction as "irrational" and estimate that the soil is nearing its limit of compaction.

Subsidence effects on neighborhoods

Iztapalapa, one of the neighborhoods most affected by subsidence, experiences a sinking rate of 40 centimeters per year. The borough has many wells but lacks drinking water, leading to floods as the ground sinks and water remains on the surface. Over 70 percent of the city's ground is considered flood-prone by UNAM researchers.

Infrastructure damage and risks

Subsidence has caused damage to various infrastructure elements, including the metro, sanitation systems, roads, and housing. The international airport is among the most affected areas, with a subsidence rate similar to that of the Angel of Independence. Roads crack and buildings tilt, requiring ongoing maintenance and repair.

Future risks and calls for action

UNAM geologists warn that certain areas could become uninhabitable within less than 10 years, leading to forced population displacements. They mention a "point of no return," suggesting that stopping the subsidence process is now beyond the reach of authorities. They advocate for urban decentralization to prevent mass displacement and criticize the lack of institutional response to a long-known issue.

Historical context and ongoing concern

Subsidence in Mexico City has been documented since at least 1925, shortly after the Angel of Independence was inaugurated. In the 1990s and 2000s, some areas were already sinking at a rate of about 35 centimeters per year. Recent data from 2025 to 2026 shows continued subsidence, with some areas sinking more than 24 centimeters annually.