Geographical Challenges of Mexico City
Mexico City is one of the worst places in the world when it comes to geography. Despite its rank as the sixth-largest city globally and the largest city in Mexico, it was constructed in one of the most unfavorable locations possible. The first thing to know is that the city is sinking at an alarming rate. On average, the city sinks about 20 inches per year, and in some places, even up to 1.5 feet per year. Currently, it is forecasted that by the end of the 21st century, sections of Mexico City will be 65 feet below its current elevation, with some parts likely to sink upwards of 100 feet.
In the beginning…
To understand Mexico City's issue, one needs to go back about 700 years. Before it became a massive urban city with 9 million people, the landscape was an expansive lake known as Texcoco, situated within a valley surrounded by mountains and volcanic peaks. The reason for settling here traces back to an Aztec prophecy. According to this prophecy, the city's location would be wherever an eagle was spotted eating a snake atop a cactus. The Aztecs found this omen on a swampy island in the lake. Over 200 years, the island was expanded using floating plots of land called Chinampas, giving rise to the former city of Tenochtitlan.
The Spanish Conquest and their city revisions
When the Spanish arrived in 1519, Tenochtitlan had grown to a size five times that of London during the reign of Henry VIII. It was characterized by an intricate system of canals, dams, clean water sources, and a well-defended position. (If you Google Xochimilco, you can see remnants of these canals.) Despite this, with the help of Cortes and a few Spanish troops, the Tlaxcalans managed to attack and destroy the city. The Spanish eventually renamed Tenochtitlan, Mexico City, and from there, things took a downturn.
The Growth of a New City
In contrast to the ingenuity of the Aztecs, the Spanish failed to grasp the importance of the dams and instead began filling in the lake to reclaim land for their own vision of a city. However, lacking the intricate dam and canal system, the city became vulnerable to floods, leading to catastrophic floods that still occur today. One of the worst floods happened in 1629 and lasted for five years.
Why don’t we have water
As Mexico City's population surpassed 9 million residents, more land was reclaimed to the point that the city, once situated on a lake, now grapples with severe droughts. The government's solution was to drill into the aquifers beneath the city, which coincidentally are under soft clay. With the increased water extraction, the soil's stability rapidly deteriorated, causing the city to sink. Despite receiving more rain than much of the world, Mexico City struggles to capture and utilize this water.
Well isn’t it the consequences of my own actions…
Given that the sinking varies across the area, preventing roads and buildings from occasionally sinking into holes in the ground has become increasingly complicated. Numerous areas feature older buildings that occasionally lean like the Leaning Tower of Pisa. Streets and sidewalks are often uneven due to builders cutting corners (pun intended). Additionally, the region experiences frequent seismic activity, and earthquakes have been both common and devastating over the decades.
In the end, after centuries of change, what was once an advanced city on a lake has transformed into a 577-mile uneven parking lot. Nature always prevails, and it's only a matter of time before the city sinks to a point beyond recovery. Nonetheless, we can maintain faith that engineers will find solutions to address this problem.