How it began
Chinampas are a form of raised field agriculture developed in the shallow lakes of the Valley of Mexico. There is evidence that the Nahua settlement of Culhuacan built the first chinampas about 1100 CE, and the earliest securely dated fields are from 1150 to 1350. Farmers kept small chinampas beside their homes in Lakes Xochimilco and Chalco. The Aztecs did not invent the technique but were the first to develop it for large-scale cultivation.
How it works
A chinampa is a narrow artificial island surrounded by canals. Farmers fenced a plot with stakes and interwoven reeds, then piled up lake mud, sediment and decaying vegetation until the surface rose above the water. Bonpland willows planted along the edges hold the soil and shelter crops. Mud dredged from the canals is spread on the beds as fertilizer, and the surrounding water keeps the soil moist, so the fields can stay in almost continuous cultivation.
Who pushed back
With the destruction of dams and sluice gates during the Spanish conquest, many chinampa fields were abandoned, and the loss of Aztec hydraulic control reduced the area and the fresh water available. Many lakeshore towns kept their chinampas through the colonial era. In Xochimilco the cultivated area fell by more than 60 percent in the second half of the 20th century, and urban growth and polluted water continue to threaten it.
What changed first
During the late Aztec period, from 1325 to 1521, canals and flood controls allowed chinampas to expand, linked to dense population and growing cities. Chinampa farms ringed the capital Tenochtitlan, and their multiple harvests each year became a large part of its food supply. Crops included maize, beans, squash, amaranth, tomatoes, chili peppers and flowers.
Where it stands today
Chinampas are still worked in Xochimilco, in the south of Mexico City, by farmers known as chinamperos who pass on the knowledge orally. The Food and Agriculture Organization lists the system as a Globally Important Agricultural Heritage System, and the area lies within a UNESCO World Heritage property. Researchers study it as a model for urban farming, and a first revival program began in Mexico in 1975.
