What makes this place unique?
It is the world’s largest city at an elevation higher than 2000 meters.
With 21.2 million residents it rivals New York City for the title of largest metropolis
in the Americas, and it is one of the world’s oldest continuously populated urban areas.
But what truly sets this megalopolis apart is also its biggest challenge.
It is the largest city on Earth without direct access to a significant body of water, although
that wasn’t always the case.
This is an examination of Mexico City and the water crisis that threatens its continued
prosperity.
Nearly seven centuries ago, the Aztecs came across an island in the middle of a lake,
in a vast valley, more than 2,000 meters above sea level, hundreds of kilometers from the
nearest coast.
Three hundred years later, a small group of Spanish explorers led by Hernan Cortes arrived,
and what they found was a thriving capital city, the heartbeat of the Aztec empire with
300,000 souls.
It was called Tenochtitlan, and it amazed the Europeans.
Its labyrinth of canals dividing a network of manmade islands reminded them of Venice,
and they wanted it for themselves.
[Dr. John Pohl] “There in the center of the lake was this gleaming white city, it
was something they’d never seen before.
And for us we can almost imagine it as Dorothy looking at Oz for the first time.
It was far larger at a quarter of a million people than any city they’d ever seen in
Europe.”
Armed with superior weaponry — and the most powerful exterminating agent, disease — the
Europeans wiped the Aztecs out and systematically dismantled their great temples and pyramids.
Then, they set out to quickly build the most renowned city in the Americas.
They rejected the Aztec way of living harmoniously with the land and, instead, filled their canals,
destroyed their “floating farms,” and drained water from the lake until it was completely
empty.
This set the city on a collision course with nature.
Over time, it has grown to cover the entire lakebed, and well beyond.
And because two volcanos — one of them still active — loom over the city from the south,
the soil is a mix of clay from the lake and volcanic rock.
That’s an unusual foundation to build a sprawling, heavy, concrete jungle on—and
it’s why the city is sinking.
But people keep on arriving, because the defining feature of Mexico City is centralism, the
idea that all paths lead here.
What used to be trails converging on grassy highlands, became dirt roads used by carts
and donkeys loaded with goods, and are now the arterial roads that move millions.
The explosion of Mexico City’s population — like other megalopolises around the world
— follows the widespread adoption of the motor vehicle.
In 1950, its population was 3.1 million.
As paved highways became more common, it jumped to 5.5 million by 1960, then it nearly tripled
to 14 million inhabitants by 1980.
This boom has exacerbated the city’s two most urgent challenges: bringing in enough
water for twenty-one million people, while simultaneously sending away the millions of
litres of wastewater they produce each day.
The city is failing on both fronts.
Now, it’s worth noting that crime is not Mexico City’s most pressing concern.
It can be a dangerous place, but the reality is that - while the country has seen its murder
rate rise as drug cartels battle for territory - the Federal District has some of the lowest
crime rates in Mexico.
It has installed more than 22,000 surveillance cameras throughout its 16 boroughs and put
thousands more police officers on the street.
Increased security keeps violent crime in check and creates opportunities for educated
and artistically-inclined young people from the surrounding states.
It’s a young, vibrant place with an economy that accounts for one-quarter of the country’s
GDP while holding more than one-fifth of its population, that’s one of the highest capital-to-national
ratios in the world.
Centralism, remember?
It’s neighborhoods are diverse, and flow endlessly into one another.
One minute it feels like you’re in Paris, turn the corner and its Manhattan, but just
a few streets over lie the rundown avenidas of Tijuana.
Above all, it’s crowded.
Mexico City is the most congested place in the world.
Although it has an excellent, twelve line metro system that’s cheap enough for anyone
to ride, its five million cars snarl the roadways on the streets above.
Which brings us back to the water crisis.
The city has a powerful one-two combination that amplifies the intense droughts and downpours
that come with climate change—a gigantic concrete slab situated at the bottom of a
valley surrounded by mountains that block in its pollution.
It’s a heat sink that speeds up evaporation while preventing rainwater from entering the
water table below.
The city had been counting on its Grand Canal to expel 280 cubic meters of wastewater a
second from its overflowing sewers.
But it relies on gravity to pull the water down.
As the city sinks, the canal becomes less and less effective.
Today, it works at just 30% of capacity.
The ever-shifting ground also means that many of the 8,000 miles of pipes delivering drinking
water leak, resulting in the devastating loss of up to 40% of what’s originally pumped
up from sources many miles away.
And that’s just the situation for the residents lucky enough to have a constant supply.
20% or more of Mexico City residents can’t even count on water flowing from their taps
everyday.
This has created an incredibly inefficient system where fleets of trucks fill up their
tanks and drive to deliver to customers by hose, house by house.
That’s an expensive way to live, and it's why many low income families spend 10 percent
of their monthly income for 10 gallons per person, per day.
[Juan Santibanez] “In Iztapalapa, there are 1,000 trucks distributing water to 2,000,000
people, which is nowhere near enough to meet the needs of those people.”
[PBS reporter] “It’s expensive, inefficient, and customers like Sylvestre Fernandez — a
struggling cab driver — are not satisfied.”
[Fernandez] “Sometimes it takes one, or up to five, days after we request it.
And sometimes, we can’t buy other things, like diapers for the baby because we have
to pay for water.”
[Bryce] Meanwhile, residents living in wealthy neighborhoods consume 100 gallons on average
a day from their free-flowing taps and pay just one-tenth the price.
This rampant inequality amplifies the destabilizing effects of climate change.
And water starved communities like these exist all over the world—which is exactly why
the U.S. Pentagon calls climate change a “threat multiplier.”
The director of Mexico City’s water system explains what a severe drought could mean,
“we’re facing a potential disaster.
There is no way we can provide enough trucks of water to deal with that scenario...there
is the serious possibility of unrest.”
One study says up to 10% of Mexico’s population could eventually head north if droughts and
floods get out of control.
The recent migrant crisis in Europe underlines how difficult it is to stop hundreds of thousands
of people who are fleeing for their lives from crossing borders, seas, and yes, even
fences and walls.
To help solve problems like this, Mexico City’s local government is gaining more power to
govern itself.
It clearly needs it.
The deeply unpopular President Pena Nieto has simultaneously cut all funding for Mexico
City’s water fixes, even as he advocates for a new multi-billion mega-airport in a
part of the city — a dry lakebed — that could make the water problem worse.
There’s no easy solution to this ongoing problem, but Mexico City has no shortage of
smart people eager to get the job done.
One of the longer term solutions could be the widespread adoption of rainwater harvesting
that’s being tried in some states.
“Rainwater harvesting is actually quite a simple thing.
What we do is, the rainwater that falls on the roof of the house, we channel it to a
sistern.
And we pass through a very simple process that first flushes the water and filters it.
Why are we pumping water from over here when we have water falling on us from the sky,
for free in huge abundance?
We just haven’t known up until now how to take advantage of that.”
In the short run though, a good place to start, is by fixing one leaky pipe or sinking section
of canal at a time.
Thanks for watching.
Many of the ideas in this video came from a fantastic piece in the New York Times by
Michael Kimmelman—which I read while on a recent visit to Mexico City.
I saw a lot of the things I just talked about, good and bad, firsthand on my trip.
I’m looking forward to discussing and answering any questions you might have in the comments
below.
This is the first video in our new, weekly MEGACITIES series that will combine two of
our most popular topics in order to profile the biggest challenges of the 21st century.
Until next time, for TDC, I’m Bryce Plank.