Lake Texcoco - Artificial Drainage

Artificial Drainage

Mexico City suffered from periodic floods; in 1604 the lake flooded the city, with an even more severe flood following in 1607. Under the direction of Enrico Martínez, a drain was built to control the level of the lake, but in 1629 another flood kept most of the city covered for five years. At that time, it was debated whether to relocate the city, but the Spanish authorities decided to keep the current location.

Eventually the lake was drained by the channels and a tunnel to the Pánuco River, but even that could not stop floods, since by then most of the city was under the water table. The flooding could not be completely controlled until the twentieth century. In 1967, construction of the Drenaje Profundo ("Deep Drainage System"), a network of several hundred kilometers of tunnels, was done, at a depth between 30 and 250 metres (98 and 820 ft). The central tunnel has a diameter of 6.5 metres (21.3 ft) and carries rain water out of the basin.

The ecological consequences of the draining were enormous. Parts of the valleys were turned semi-arid, and even today Mexico City suffers for lack of water. Currently, Mexico City is sinking at a rate of a few centimeters every year because of water removal and pumping of underground reservoirs.

The term "Texcoco Lake" now refers only to a small area surrounded by salt marshes 4 kilometres (2.5 mi) east of Mexico City, which covers the ancient lake bed. Also there are small remnants of the lakes of Xochimilco, Chalco, and Zumpango.

Several species indigenous to the lake are now extinct or endangered (e.g. axolotls).

The modern Texcoco Lake has a high concentration of salts and its waters are evaporated for their processing. A Mexican company, "Sosa Texcoco S.A" has an 800-hectare (2,000-acre) solar evaporator known as "El caracol".