The lacustrine landscape of Xochimilco constitutes the only remainder of traditional ground occupation in the lagoons of the Mexico City basin before the Spanish conquest.
The Aztecs built Tenochtitlan on an island around 1325. Issues arose when the cities' constant expansion eventually caused them to run out of room to build. As the empire grew, more sources of food were required. At times this meant conquering more land; at other times it meant expanding the chinampa system. Chinampas is a type of Mesoamerican agriculture, invented by the Aztec civilization, which used small, rectangular areas of fertile arable land to grow crops and expand territory on the shallow lakebeds in the Valley of Mexico. This made Tenochtitlan a floating city, occupying most of the lake of Xochimilco. They are an exceptional agricultural system, based on the combination of environmental factors and human creativity.
The indigenous communities in the valley of Mexico (Xochimilco & Tláhuac) have used this agricultural system for 2,000 years to produce the necessary food for the region. The human-made islands in the shallow lake are one of the most productive and sustainable agricultural systems in the world. This productivity, both in the number of crops that the chinampas produce per year and in the efficiency per unit of sown area, explains the great ability this work intensive system had to survive throughout the centuries.
The chinampa system is highly threatened due to the introduction of new agricultural technology, excessive ground-water extraction in the area, abandonment, development pressures and contamination. Sustainable conservation and management policies need to be implemented to ensure that the conditions of the chinampa system are not further eroded. 40% of the water consumed in Mexico City comes from Xochimilco.
Today, the cultivation of amaranth has become one of the most important economic activities in Mexico. The Amaranth plant covers more than 220 Hectares of Xochimilco. Its process lasts 180 days. Not only than, but the chinampa community that quantifies 40 thousands tons of production each year, feeds the most populated city in Mexico, and one of the most populated cities in the world.