Chinampas, The Floating Gardens of Mexico

Human sacrifice. This is probably the first thing that comes to people’s minds when they think about the Aztecs. However, there is much more to Aztec civilisation than this practice. By 1519, when the first Spanish conquistadors under Hernán Cortés landed in Mexico, the Aztecs were in control of an empire that was inhabited by a population of 5 to 6 million people. This large population meant that the exploitation of the landscape for agricultural purposes had to be intensified. This can be seen in the use of the chinampa agricultural system, the so-called ‘floating gardens’ which can be found on the shallow lake beds in the Valley of Mexico.

An a rtist’s impression of part of the canal network linking chinampas around Tenochtitlan.  Photo source: Mexicolore

Although the origins of chinampa agriculture in the Valley of Mexico remain unclear, it is said to have been used throughout Mesoamerica centuries prior to the rise of the Aztecs. However, with the dawn of the Aztec Empire, a systematic programme of construction was carried out over a short period of time. This planning can be seen in the overall uniformity in chinampa size and orientation, as observed in aerial surveys. While the need to sustain large population provided prompted the Aztecs to undertake this massive project, its ability to organise manpower provided the means for its accomplishment.

The lake system within the Valley of Mexico at the time of the Spanish Conquest, showing distribution of the chinampas (Wikimedia).

A chinampa plot was constructed by staking out a rectangular enclosure, about 30 m in length and 2.5 m in width, into the marshy lakebed. The enclosure would then be fenced in by joining the stakes with wattle. After that, the fenced in area would be filled with mud and decaying vegetation. In order to prevent the roots from becoming water-logged, it was important that the fill brought the chinampa plot above the lake level. While constructing the next plot, which would be parallel to the first, a narrow canal for the passage of canoe would be left in between these two chinampa plots. The canals surrounding the chinampa plots formed an illusion that these agricultural lands were floating on water, hence its misattribution as ‘floating gardens’. To further stabilise these plots of land, willows were planted around the perimeter. This is due to the dense root system which, over time, anchored the retaining walls of the structure and reduced the effects of erosion.

In order to ensure that the chinampas produced good harvests throughout the year, it was vital that the supply of water was well managed. During the rainy season, flooding would have been a problem. Hence, a sophisticated drainage system, which included dams, sluice gates and canals, were put in place to counter this problem. This management of the supply of water is further evidence of the well organised agricultural project by the Aztec Empire. During the dry season, however, moisture had to be maintained, and this was done manually by carrying water in containers from the canals to the plants in the chinampa plots. As for fertilisers, the Aztecs used human excrement collected in canoes from the city of Tenochtitlan. By using human excrement to fertilise the crops, the Aztecs were also able to create a healthier living environment as the city’s wastewater would have also been treated. It has even been claimed that the city of Mexico once attempted to create a wastewater treatment system which functioned along the lines of the Aztec chinampa system.     

What I found most fascinating about the chinampas is human agency. Although the Aztecs may seem like a blood-thirsty race, their ability to exploit the landscape to their advantage shows human ingenuity and sophistication. In addition, the organisation of the chinampa building programme and the management of its water supply by the Aztec Empire is further evidence of the highly developed society that was attained by the Aztec peoples. The fact that a modern city is trying to emulate this ancient system in order to solve its water treatment problem also attests to the complexity of Aztec society.

For more information about the chinampas, check this site out: http://www.chinampas.info/     

Featured image: An artist’s depiction of the chinampas. Photo source .

By Ḏḥwty

References

Encyclopaedia Britannica, 2013. Aztec. [Online]
Available at: http://www.britannica.com/EBchecked/topic/46981/Aztec
[Accessed 31 March 2014].

Evans, S. T., 2013. Ancient Mexico and Central America: Archaeology and Culture History. 3rd ed. London: Thames and Hudson.

Sprouts in the Sidewalk, 2014. Chinampas of Tenochtitlan. [Online]
Available at: http://sidewalksprouts.wordpress.com/history/international-history-of-urban-ag/tenochtitlan/
[Accessed 31 March 2014].

Townsend, R. F., 1992. The Aztecs. London: Thames and Hudson.

Trigger, B. G., 2003. Understanding Early Civilizations. Cambridge: Cambridge University Press.