How did the draining of lakes change the Valley of Mexico?

The draining of the five interlocking lakes in the Valley of Mexico, which began in the 17th century to prevent flooding, fundamentally transformed the region's geography and urban stability. While intended to create new farmland, the project failed in that regard because the exposed lake beds were too saline for cultivation.123

The environmental and structural consequences have been severe:

• Subsidence: Because the city was built on unstable clay sheets formerly covered by water, the removal of the lakes—combined with the modern depletion of underground aquifers—has caused the city to sink and its buildings to settle unevenly.42
• Air Pollution: The dry lake beds, particularly Lake Texcoco, have become sources of dust that blow over the urban area, significantly contributing to the city's air pollution.12
• Ecological Loss: The drainage, alongside forest destruction, led to the local extinction of various fauna and the loss of the vast water area that once defined the Anáhuac region.23

Today, only remnants like the Xochimilco floating gardens and salt marshes remain of the original lacustrine landscape.2