Question for October 2008

Where did the aqueduct go to (from Tenochtitlan)?? Asked by Northmead Junior School. Chosen and answered by Professor Michael E. Smith

Bridges, Aqueducts and the Water Supply of Tenochtitlan. Here Professor Smith answers the question from Northmead Junior School (above) as well as the following:-
• How did the Aztecs get their water? (Loseley Fields Primary School)
• Did the Aztecs get the idea of aqueducts from the Romans? (Frith Manor Primary School), and
• How did the Aztecs build their bridges (causeways)? (Claygate Primary School)

Most Aztec cities and towns were located near sources of fresh water. Some were built alongside rivers or streams, and others had springs nearby. The imperial capital Tenochtitlan, however, faced two special challenges to get fresh water for drinking and other uses. First, the city was built on an island in a lake of salty water that was not good for drinking (see picture 1). Second, Tenochtitlan grew into the largest city in the New World (more than 100,000 persons), so its residents needed lots of fresh water. To solve the water problem, the engineers of Tenochtitlan built a canal or aqueduct to carry water from some springs on the shore out to the island city. Those springs were located in a place called Chapultepec (“place of the grasshopper”), today a major park in Mexico City (picture 2).

The word “aqueduct” can cause confusion because it has two meanings, one general and one specific. The Tenochtitlan canal fits the more general meaning: an aqueduct is “a canal or other human-made channel to carry water over a long distance.” Picture 3 shows a reconstruction of the main aqueduct that carried water from Chapultepec to Tenochtitlan. The builders first constructed an elevated causeway across the lake (light-colored section), using sand, dirt, and rocks and held in place by large wood stakes. The painting of Tenochtitlan (picture 1) shows four of these causeways. They were used for people to walk between the city and the shore. A raised aqueduct was then built on top of the Chapultepec causeway (the one at the lower center of picture 1). This was probably built of stones and mud, held in place with more wood stakes.

The second and more specific meaning of aqueduct does not fit the Tenochtitlan canals very well: “a bridge-like structure that carries a canal over a ravine of other obstacle.” When most people hear this definition, they think of a Roman-style aqueduct. The Romans built large and impressive aqueducts out of stone, held up by arches. The Romans were master builders (more advanced than the Aztecs in construction and architecture), and their aqueducts were among the finest architectural constructions of the ancient world. We are still amazed at their quality today.

The Aztecs did build a few irrigation canals that crossed ravines, and they built some bridges. But we don’t know much about them. They definitely did NOT use arches, like the Romans, and they did not built large rope bridges like the Incas. There were no contacts at all between the Romans and the Aztecs! (Roman civilization rose and fell centuries before the Aztecs came to power). After the Spaniards conquered the Aztecs, however, Spaniards brought their knowledge of Roman-style aqueducts to Mexico. They built some large aqueducts with arches in central Mexico, but only after the Aztecs had been conquered (picture 4).

Picture sources:-
• Picture 1: Painting of Tenochtitlan by Luis Covarrubias, National Anthropology Museum, Mexico City (photo courtesy of Michael Smith)
• Picture 2: Photo by Ian Mursell/Mexicolore
• Picture 3: Causeway section: Bribiesca Castrejón, José Luis, 1958, “El agua potable en la república Mexicana: los abastecimientos en la época prehispánica.” Ingeniería Hidraúlica en México 12(2):69-82. Drawing on page 77, editing and color added by ME Smith.
• Picture 4: Detail from a screen mural by Roberto Cueva del Río (1976), photo by Ian Mursell/Mexicolore.

Professor Michael E. Smith has answered 5 questions altogether.

Where did the aqueduct go to (from Tenochtitlan)?

Were there rich and poor in Aztec times?

If the Aztecs died of old age how long did they expect to live for?

Why did Aztec houses have no windows?

Did being poor in Aztec times affect you in the afterlife? (2)

Comments (2)

RainbowOcelott

28th Feb 2016

Katia H So true, so very true.

Katia H

13th Jul 2013

I used to think the Aztecs’ aqueducts were arched like the Roman style, so thanks for clearing it up. Who knows though, maybe the Aztecs would have developed even more sophisticated architecture if the Spaniards hadn’t crashed the party...