Every rainy season, chilangos and chilangas surely ask Tláloc, why does Mexico City flood so much? Here at Sopitas.com, we look for the answers, which, mind you, are related to a host of factors, such as geography, infrastructure, and even civil issues like not littering the streets.
We also found some alternatives to prevent Mexico City from flooding every rainy season… although, the surprise is none other than returning to the principles of the first inhabitants of this great city, among other mechanisms.
Why does Mexico City flood?
Once upon a time, between 1629 and 1635, a series of floods collapsed Mexico City—the former Tenochtitlán—leaving 30,000 dead and the idea of moving the capital of New Spain to another location.
Why hasn’t Cutzamala River filled up yet, even though it’s rained so much?
That didn’t happen. What did happen was that a series of plans began, which advanced slowly, but very slowly, to build a drainage network to prevent Mexico City from flooding.
Increasingly extreme rainfall
However, in the 21st century, Mexico City faces new challenges and contexts, such as intense rainfall—in increasingly extreme climates—like the one on June 2, 2025, when more than 10 million cubic meters of water fell in just a few hours. To give you an idea, almost enough to fill the Madin Dam.
“In Mexico City, we have a series of circumstances that clearly predispose us to these floods.
Mexico City is built in a closed basin; it’s like a deep bowl, and all the rain that falls there naturally wants to accumulate in the center, which is why we used to have large lakes,” explained Enrique Lomnitz, co-founder of Isla Urbana, on MVS Noticias with Ana Francisca Vega.
Here we have the geographic factor that influences flooding in Mexico City, which posed serious challenges even for the Aztec civilization.
In 1449, Tenochtitlán suffered the consequences of its first major flood, and to prevent a repeat, Nezahualcóyotl proposed and built a dike or levee from Atzacualco to Iztapalapa in the south.
According to Jorge Gurría Lacroix in “The Drainage in the Valley of Mexico During the New Spanish Era,” it was a “grandiose” work of hydraulic engineering to regulate the entry and exit of water, as well as the passage of cannons.
Thanks to this construction, the lagoon was divided into two parts: Texcoco (saltwater) and the freshwater Laguna de México. The lakes of Chalco and Xochimilco, fed in turn by springs of fresh, crystalline water, drained into the latter. Can you imagine?
The Nezahualcóyotl levee and other dikes helped prevent flooding in Tenochtitlán, as did the lake areas that absorbed excess or peak rainfall.
However, once the Spanish Crown arrived in Tenochtitlán, this system disappeared with efforts to dry up the lakes and, centuries later, by channeling the rivers to prevent flooding, something that has not been fully achieved.
The Sinking of Mexico City
“What we have done over generations is build drainage tunnels and other infrastructure to try to evacuate the water when it falls most rapidly, but we have two problems.”
Isla Urbana co-founder Enrique Lomnitz explained that one of the problems is the “incredible” amount of water that falls in a short period of time, and the other is that since Mexico City is built on a soft bed—of what was once a large lake—it is sinking.
And, in fact, there are parts of eastern Mexico City that sink around 50 cm per year.
Trash
The trash, oil, and waste that people throw in the streets are also another cause of flooding in Mexico City.
In 2014, the then-government of the Federal District (CDMX) identified trash as the cause of 50% of flooding.
“50% of flooding is caused by clogged drains,” it stated.
Alternatives: What can we do?
The first and easiest is to not throw trash in the street to avoid clogged drains and flooding in your neighborhood.
A comprehensive urban architecture plan
Another alternative, this one more elaborate, is the development of comprehensive construction plans.
That is, when building a house or building, factors ranging from the location of the land to the materials used should be evaluated.
Víctor Arvizu, coordinator of the Energy Specialization in Sustainable Building at Ibero-American University, explained in one of the university’s publications that construction in high-risk areas should be prohibited, taking into account human and social factors when undertaking a project.
Other factors include using water-resistant materials, resorting to elevated buildings, and harnessing rainwater by constructing sloped covered terraces that, instead of channeling water to the sewer, carry it to a cistern where it can be stored.
Asphalt also counts.
The use of permeable pavements on streets is another option to prevent puddles and flooding, as they allow water to pass downward instead of accumulating on the surface.
According to Víctor Arvizu, these permeable pavements and water traps would allow rainwater to be directed to median strips and parks.
The Restoration of Lake Districts in the City
“Instead of piping and removing water from the basin, we can think about expanding infrastructure or more lake-like areas… we could greatly increase the capacity to retain water in lakes and wetlands; this is the type of thing being done in China.”
In other words, representing infrastructure. Enrique Lomnitz exemplified this with the case of China, where they are rethinking their system based on “sponge city” models.
Something like the lake districts in Xochimilco designed to absorb peaks of water when it rains.
Can we bring back the rivers, as happened in South Korea?
“It can be unpiped, although it requires political will, resources, and the will to do so. We could live in a city crisscrossed by clean rivers instead of drains,” Lomnitz explained.
Take the example of what happened to the Cheonggyecheon River in Seoul. This 5.8 km river was invaded in the 1950s, highly polluted, and covered with concrete at the end of that decade.
Twenty years later, a highway was built over it until the early 2000s, when the Seoul government decided to remove the highway and restore the river to improve the environment, mobility, and public spaces.
This project began in 2003 and was completed in 2005. It cost around $367 million, but its benefits are estimated today at around $3.5 billion.
Source: sopitas
