Indigenous People Day: Irrigation Methods of Tenochtitlan

Image Source: Wikimedia Commons
El Templo Mayor in Tenochtitlan

Even today, 2,000 years after the heyday of the Roman civilization, tourists flock to Italy to see the iconic Roman Coliseum, the dignified Roman Forum, and the beautiful ruins of the city of Pompeii.  Although the average ancient Roman citizen enjoyed these treasures as well, the true pride of the city of Rome was its huge and efficient sewer system, its bountiful aqueducts, and its numerous public baths.   Roman civic engineering is world-famous today, and rightly so, but the Romans were not the only pre-modern civilization to reach incredible heights in the field of civic engineering.  The Aztec capital of Tenochtitlan, which lies just under Mexico City today, supported almost half a million people in a clean, sustainable, easily defensible metropolis that surely would have knocked an ancient Roman’s sandals off!  Tenochtitlan was so innovative and yet so well-designed that the Spanish Conquistadores who witnessed the white-painted metropolis firsthand — studded with massive 60 meter tall pyramids, huge markets, and beautiful gardens fed by sophisticated aqueducts — thought that they were dreaming.

Image Source: Wikimedia Commons
European Map of Tenochtitlan circa 1524

There is an impression common in popular culture today that Native American groups lived in small, isolated, primitive groups, and did not build cities, or possess techniques of engineering or math.  In fact, the art of urban planning reached new heights from Bolivia all the way to The Pacific Northwest!  Although Tenochtitlan was certainly not the only major city of the Americas, it may have been the biggest, and, like Rome, it was a hub of trade and culture that attracted people from many different parts of their world.  The militaristic Romans surely would have been jealous of Tenochtitlan’s most defining feature:  it was a “floating city”  built in the middle of a large lake.  Much of the travel to and around the city was done by canoe, not on foot.  There were only three bridges connecting the city to the land, making the entire city an easily defensible fortress in times of war.  In the event of siege, the Aztecs had built in an even more astonishing feature: the city produced its own food in floating gardens known as chinampas, which could produce 6 to 7 crops a year.  Even the most hardened Roman Centurion’s jaw would be on the floor at the sheer genius of this seamless urban/military planning.

Image Source:
Map of Tenochtitlan

About a thousand years ago, the Aztec people, who today prefer to be called the Mexica, were considered a rowdy, uncultured tribe among the many groups who populated the Valley of Mexico.  The fertile Valley of Mexico had already seen several urban civilizations come and go over the previous centuries, most impressively at the city of Teotihuacan, which boasts a pyramid as large as the ones at Giza. According to legend, it had been prophesized that the Mexica would build their great city on the site where they saw an eagle eating a snake on top of a cactus.  This image is now at the center of the Mexican flag, but when originally sighted it presented a problem: the sacred eagle was in the middle of a huge, marshy, mosquito-filled lake!  It’s more likely that their neighbors chased the Mexica to this undesirable real estate and trapped them there, but in any case the construction of this unlikely city is all the more incredible because it was the work of people we might call today “the underdogs.” 

Image Source: Wikimedia Commons
Surviving Mexica Chinampa

Undeterred, the Mexica got to work, and around 1376 began the long, laborious process of building their magnificent capital.   The chief architect and engineer of Tenochtitlan, Acamapichtli, had the innovative answer to building on marshland.  To anchor their buildings, the Mexica used 30 foot stakes of wood, driven into the ground and further surrounded by brick and rock.  This provided a surprisingly durable foundation for the city that eventually reached 14 square kilometers using this, and one other, technique.  The second technique, chinampas, created agriculturally productive land out of almost nothing.  By interweaving reeds and stakes and placing them on the rich, mucky bottom of the lake, the Mexica then piled on more soil until it reached the surface of the lake. This gradually created mats of vegetation that, as the roots grew in, became more and more stable and solid.  Over years, the mats, with their built-in irrigation system, became islands that could be planted and harvested up to 7 times per year, making it one of the most effective farming methods ever created.  Stocked with food, clean water, and stable ground on which to build, the city of Tenochtitlan boomed, and was larger (and much cleaner) than many major European cities when the Conquistadores arrived.  Although Tenochtitlan was razed and Mexico City built in its place, the wonders of the floating city prove without a doubt that the drive to innovate, engineer, experiment, and improve belongs to no one culture around the world, but to all of us.

To learn more:
Spanish Eyewitness
Engineering an Empire Documentary
In-depth paper on Hydrology and Chinampas
Life in Tenochtitlan

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.