Mexico City is drinking itself into the ground

Mexico City's cathedral, which had to be propped up with stone wedges as it was being built to stop it sinking. Image: Francisco Diez

When the Aztecs founded the city of Tenochtitlán in the middle of a lake, they thought they were being incredibly clever.

It was 1325, the height of the era of Mesoamerican tribes vying for supremacy in the narrowing strip between the Pacific Ocean and the Caribbean Gulf, and a small island on the western side of Lake Texcoco seemed like a pretty good place to be. 

The Mexica people who lived there – and from whose tribe the name Mexico now comes – became enormously successful. Their Aztec Empire was the most formidable force on the continent, exerted control and influence for thousands of miles around, and established trading relationships stretching as far as the Inca Empire in modern-day Peru.

Their island city, smattered with canals, causeways, and dykes, was a lesson in sustainability.

Lake Texcoco and the city of Tenochtitlán before s*** went down. Image: Yavidaxiu.

The channels they built provided natural irrigation and water management, while floating gardens called chinampas kept the city fed as it grew to an astonishing size. By the time the Spanish conquistadores arrived in the 16th century, the city had approximately 300,000 residents – making it five times the size of London at the time.

The Mexico City of today is a very different story.

A choked-up Mexico City today. Image: Fidel Gonzalez/creative commons.

Up no creek with no canoe

A choking, smog-shrouded sprawl of 21m people. It has no island, no lake, a water shortage that means millions are left with empty taps on a regular basis, and is sinking at an astonishing rate.

Roughly 20 per cent of Mexico City’s residents cannot guarantee that water will come out of their taps every day, and the ground is sinking by as much as nine inches a year in some suburbs. That’s the equivalent of nearly a storey a decade.

The city’s cathedral, which took more than 200 years to build, has a leaning chapel and bell tower, propped up by stone wedges to stop the whole thing crumbling down. The Gilded Angel of Independence – a local tourist hotspot and national landmark – was built with nine shallow steps leading up from the street below. As the surrounding area has sunk, an extra 14 large steps have been added as the angel is increasingly left marooned above a vanishing city.

Slanted buildings leer menacingly over pavements, their doors and windows no longer in alignment with their friends as if crudely displaced from a grotesque theme park funhouse. Terraced streets built on level ground now undulate, with wavy gables crowding up against each other in parts, and pulling away in others, while city-dwellers struggle up hilly pavements where once the path was flat.

In Iztapalapa, a suburb of approximately 2m people built on the ancient lake’s southern shores in the city’s south-east, 15 primary schools have crumbled or caved in, and a teenager was swallowed up when a gaping crack appeared in the street.

So what happened?

As per usual, the blame can be placed squarely on the shoulders of the pesky European invaders.

Xochimilco, the last vestige of Mexico City's lakeside history. Image: Owen Prior.

Veni, vidi, conquistadori

When Hernán Cortes entered the city in 1519, he was “stunned by its beauty and its size”, and in awe of a city where he was welcomed as a god and given plush lodgings by the Aztecs. This, obviously, did not last: war ensued, and the conquistadores took control of the city and named it the capital of their new colony, the Viceroyalty of New Spain.

Where the Aztecs had constructed dykes and channels to live in harmony with the lake, the Spaniards covered them over to build roads and increase the city’s size. They started draining the lake and cutting down the forests on its shores, making the city more susceptible to intense flooding.

Mexico City suffered major floods in 1555, 1580, 1604, and 1607, before one bright spark proposed moving the capital to dry land in 1630. But after deliberating on this for a while, the authorities decided that the answer was no, and the flooding continued, with more serious deluges in 1645, 1674, 1691, 1707, 1714, 1724, 1747, and 1763.

One flood was so severe that the entire city was submerged for five whole years from 1629 – yet the city lived on, gasping for air and expanding further across the lakebed between downpours.

By the 20th century, most of the lake had been drained, and flooding became the least of the city’s worries. As it grew and grew, and poorer migrants from the surrounding country arrived in search of economic opportunity, Mexico City grew thirsty.

Which was a problem.

The Gilded Angel of Independence, which has risen above the sinking streets. Image: TJ DeGroat.

Geologically insane

The city is built on two different geological foundations. Some of the ground underneath Mexico City is volcanic soil, which was fertile and used by the Aztecs for growing crops. It was also handily water-absorbent: moisture would soak in and flow to underground aquifers easily, without damaging the structure of the soil.

But when developers built on the volcanic soil and covered it in concrete and asphalt, water could no longer get through to the soil and filter through to the aquifers on which the city relies. And other parts of the city sit on clay. This, unlike the volcanic soil, can't absorb the water, merely sandwiching it between layers of clay – like cream between layers of pastry. When the cream is sucked out, the layers of pastry crack and collapse, falling on top of one another.


And that’s what’s happened beneath Mexico City. Desperate for water in a lake basin devoid of a lake, the city has tapped into the clay soil while covering over the useful volcanic soil. And as the city is built on a mixture of both geologies, it has sunk in an uneven, mismatched way, causing dangerous fissures, cracks, and the bizarre phenomenon of wavy, undulating streets.

It is estimated that the city has dropped 10 meters in the last century; if anything the signs are that this process is accelerating.

The climate change doom blockbusters show us coastal cities dramatically engulfed by storms and waves from rising sea levels, as great ice shelves melt in the Arctic and Antarctic.

But one of the first cities claimed as victims by man-made destruction may be less cinematic: a leviathan of 21m sinking into the ground, cracking and buckling, swallowing up people, houses, and livelihoods, and starving its poorest residents of water and hope as it goes. 

Jack May is a regular contributor to CityMetric and tweets as @JackO_May.

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Brexit is an opportunity for cities to take back control

Leeds Town Hall. Image: Getty.

The Labour leader of Leeds City Council on the future of Britain’s cities.

As the negotiations about the shape of the UK’s exit from the EU continue, Britain’s most economically powerful cities outside London are arguing that the UK can be made stronger for Brexit – by allowing cities to “take back control” of service provision though new powers and freedoms

Core Cites UK, the representative voice of the cities at the centre of the ten largest economic areas outside London, has just launched an updated version of our green paper, ‘Invest Reform Trust’. The document calls for radical but deliverable proposals to allow cities to prepare for Brexit by boosting their productivity, and helping to rebalance the economy by supporting inclusive economic growth across the UK.

Despite representing areas responsible for a quarter of the UK’s economy and nearly a third of exports, city leaders have played little part in the development of the government’s approach to Brexit. Cities want a dialogue with the government on their Brexit plans and a new settlement which sees power passing from central government to local communities.

To help us deliver a Brexit that works for the UK’s cities, we are opening a dialogue with the EU Commission’s Chief Negotiator Michel Barnier to share our views of the Brexit process and what our cities want to achieve.

Most of the changes the Core Cities want to see can already be delivered by the UK. To address the fact that the productivity of UK cities lags behind competitors, we need to think differently and begin to address the structural problems in our economy before Brexit.

International evidence shows that cities which have the most control over taxes raised in their area tend to be the most productive.  The UK is significantly out of step with international competitors in the power given to cities and we are one of the most centralised countries in the world.  


Boosting the productivity of the UK’s Core Cities to the UK national average would increase the country’s national income by £70-£90bn a year. This would be a critical boost to the UK’s post-Brexit economic success.

Our green paper is clear that one-size fits all policy solutions simply can’t deal with the complexities of 21st century Britain. We need a place-based approach that looks at challenges and solutions in a different way, focused on the particular needs of local communities and local economies.

For example, our Core Cities face levels of unemployment higher than the national average, but also face shortages of skilled workers.  We need a more localised approach to skills, education and employment support with greater involvement from local democratic and business leaderships to deliver the skills to support growth in each area.

The UK will only make a success of Brexit if we are able to increase our international trade. Evidence shows city to city networks play an important role in boosting international trade.  The green paper calls for a new partnership with the Department of International trade to develop an Urban Trade programme across the UK’s cities and give cities more of a role in international trade missions.

To deliver economic growth that includes all areas of the UK, we also need to invest in our infrastructure. Not just our physical infrastructure of roads, rail telecommunications and so forth, but also our health, education and care infrastructure, ensuring that we are able to unlock the potential of our core assets, our people.

Whether you think that Brexit is a positive or a negative thing for the UK, it is clear that the process will be a challenging one.  Cities have a key role to play in delivering a good Brexit: one that sees local communities empowered and economic prosperity across all areas of the UK.

Cllr Judith Blake is leader of Leeds City Council.