So what happened to the lakes??
I had previously assumed that the lakes had dried out. Their fragile ecological balance destroyed sometime after the arrival of the Spanish, they had simply withered away.
As it turns out, it wasn't that the lakes had gotten smaller at all--it was just that the population had gotten bigger. As I imagine it, as the city slowly began to grow after the conquest it continued to extend the chinampas, the artificial islands on which the city was built. Perhaps one day, after years and years of growth, these chinampas finally reached the lake's shore and *poof:* no more lake.
But like the many people and things in Mexico, the lakes are much too resilient. The tributary streams continued to flow in and the summer rains continued to pour. I imagine it must have been quite a battle.
In 1629, a horrible flood kept parts of the city submerged for over five years. It was at this time that people began to think Mexico would not survive as the capital. Construction began on Puebla, a town only a few hours a way.
The lion's head on this building marks the flood line in this part of the city:
Mexico City, however, did survive. Today the lake flows in the form of rivers, hundreds of rivers, channeled subterraneously under the great metropolis. Every once in a while, however, the city sees signs of their tenacious existence. At even the slightest rain the streets begin to flow, unable to absorb the excess water. And like Venice, the capitol is sinking at the rate of 2 to 3 cm a year into the murky lake bed. Some places sink even faster. This church (pictured at left) goes down into the mud at a rate of 8 cm a year and a requires a bridge to access it from the street. In the plaza, the Iglesia de Jesus Nazareno (pictured at right) measures its movement with a giant pendulum, located in the center of the abbey.
The irony, of course, is that Mexico City is also facing a severe water shortage. As the population swells, the water tables shrink and the tributary streams deliver less and less each year. But I am confident that just as the people and water have continued for years, I am sure they will find a way to continue for many more.