The forgotten island

Image: Archivo Metropolis, Centro de Información de la Ciudad de México

I’m standing in the Casa del Poeta on Colonia Roma’s tree-lined Avenida Álvaro Obregón, imagining my feet subsumed in lake water. On the wall in front of me is an artist’s impression of Mexico City, then Tenochtitlan, in 1519. The image is bucolic: a neat, ordered city in the middle of a vast lake.

If a lake is like the Earth’s eye, reflecting its soul, as Henry David Thoreau wrote, then Tenochtitlan was its sparkling iris. The Grand Temple was the pupil at its centre, from which canals and causeways radiated past the agricultural lands-- the chinampas -- toward the watery outskirts, which in the picture sparkle clear and blue. The peaks of surrounding volcanoes line the edges like eyelashes, dusted with snow.

“The scale was immense,” says architect and urban planner Jorge Legorreta. “When the Spanish arrived, there were six square kilometers of city and 1,100 square kilometers of lake.” Now the city sprawls over 2,000 square kilometers, covering the dry lakebed and crawling up the sides of the valley. The city’s amphibious past is as hard to imagine as its clean-aired one.

Of the five interconnecting lakes surrounding the ancient city, only a few patches of water remain in the lakes of Xochimilco, Tlahuac, San Gregorio Atlapulco and Mixquic. Despite this, the city continues to be defined by water. From the shouts of water sellers on the streets to the problems of flooding, contamination, water shortages, and the constant aquifer extraction causing the city to sink, the Mexico City’s relationship to water is seminal.

In 1325, after being expelled from Chapultepec by local tribes, the Aztecs chose to build a city on a small island in the middle of Lake Texcoco. Legend has it that this was where they found an eagle perched on a nopal cactus devouring a snake, fulfilling an ancient prophesy. Mexican author Gonzalo Celorio wrote in his essay “Mexico, City of Paper”: “Tenochtitlan was a most improbable city, one that seemed to spring from the poetic imagination rather than from reality.”

From their island home, the Aztecs suppressed neighboring tribes and expanded the city by harnessing the system of chinampas, or floating gardens, on which they were eventually able to construct. The city grew, canals alternated with earthen streets, and drinking water flowed down from fresh springs on Chapultepec along a double aqueduct. By the time the Spanish arrived two hundred years later, Tenochtitlan was a metropolis of 250,000 people, one of the largest urban centers in the world and bigger than contemporary Paris, London, or Madrid.

The Spanish, when they saw it, could hardly believe their eyes, as documented by Bernal Díaz del Castillo, one of Hernán Cortés’s conquistadores:

“…and when we saw so many cities and villages built in the water and other great towns on dry land and that straight and level causeway going towards Mexico, we were amazed and said that it was like the enchantments they tell of in the legend of Amadis, on account of the great towers and temples and buildings rising from the water…”.

The battle for Tenochtitlan was initially a naval battle fought across the waters of the lake. During Cortés’s three-month siege in 1521, he cut off water supplies to the city by blocking the aqueduct, then built brigantines to patrol the lakes and prevent food from entering. Only then was he able to cross into the city and raze it to the ground.

While the Aztecs were content to live amid the water, with a complex system of canals, dikes, and levees to keep floods at bay, the Spaniards sought to turn the capital into a city on dry land. The result over five centuries was, according to Legorreta, “one of the most radical transformations in the history of urbanization.”

By the end of the 16th century, the five original lakes had contracted to Lake Zumpango in the north, Lake Texcoco in the east and two smaller systems to the south, but seasonal flooding was still a big problem. In 1607, the first of the great draining operations began, designed by German-born engineer Heinrich Martin. Workers pierced the surrounding hills with tunnels and dug a drainage canal that led to the Gulf of Mexico. By the beginning of the 18th century, Lake Texcoco was no more than a seasonal swamp, and Mexico City was no longer an island.

Despite this, flooding remains a problem; the city has suffered twenty-five serious floods since the conquest, some lasting as long as four years. As recently as 2005 floodwaters reached up to a meter in parts of the south and centre of the city.

With each successive drainage, the city grew, as houses spread to fill the area that was once a lakebed. By the mid-19th century the population had grown so large that aqueducts could no longer meet the city’s water needs, so in 1847 engineers dug the first artesian well, which pumped water up from an aquifer under the city.

The result was that the city began to sink into the soft, drained lakebed, an estimated nine meters since the early 1900s. There’s evidence of this around the city: the Ángel de la Independencia on Reforma, built for the centenary of Independence in 1910, now has extra stairs leading up to its entrance from the sunken road below. Likewise, there’s an old drainage pipe protruding several feet above ground level at the Cibeles fountain in Colonia Roma, today serving as a rubbish bin.

As the ground subsides, subterranean pipes break, causing more of the leaks that already waste about 40 percent of the city’s drinking water. Sewage pipes also fracture and contaminate the aquifers.

At the same time, the city’s rapid growth means water shortages for the nearly 20 million people living here. Some Mexico City residents get by on as little as one hour of running water per week, while almost all of the copious summer rainfall is flushed unused down sewers, creating a gargantuan flow of wastewater that’s beyond the capacity of the city’s few treatment plants.

The city brings in a third of its water from surrounding areas, and an estimated one million people are dependent on water trucks. Almost everyone buys bottled water or expensive home water purification systems.

Jorge Legorreta believes the key to solving Mexico City’s water problems lies in looking back to the ways of the ancient Aztecs and harnessing the available water instead of wasting or draining it. “If we don’t go back to understanding nature,” he says, “we’re going to end up with a catastrophe on our hands.”

Vivienne Stanton wrote about protesters and activists in the April, 2008 issue of Inside México.