When Mexico City’s Grand Canal was completed in the late 1800’s it was a major feat of engineering and a symbol of civic pride. At 29 miles long it could move tens of thousands of gallons of waste water per second. Flooding and sewage problems solved.
…but no. The canal uses gravity to function and Mexico City at a mile and a half above sea level was and is collapsing in on itself. Always short of water the city keeps drilling deeper and deeper for more water, weakening the ancient clay lake beds the city is built on, causing them to crumble even further.
With climate change bringing more heat and more drought, there is more evaporation and more demand for water. The pressure is building to tap into more distant reservoirs at a large cost or further drain the underground aquifers, and speed up the city’s collapse. The world has heavily invested in cities…crowded capitols with many millions of people , large economies, and an ability to destabilize a region if things come unglued.
There is a study that shows 10% of Mexicans aged 15-65 could try to emigrate north to escape rising temps, drought and floods…scattering millions of people. Given the emigration issues presently at work in North America serious consideration needs to be given.
Mexico City’s chief resilience officer says that climate change is the number 1 long term threat to the city’s future. Climate change is linked to water, health, air pollution, traffic disruption, housing vulnerability from landslides…so many linked issues that other real problems can not be addressed without dealing with the climate issue.
In 1325 the Aztecs established their capital, Tenochtitlan, here in the middle of a network of lakes. The expanded the city with landfill and planted crops on chinampas…floating gardens. The idea was to live with nature. When the Spaniards arrived they had different ideas creating streets and squares where the dikes and canals had been. They drained the lakes and cleared the forest land, suffering flood after flood. The city was even drowned for 5 straight years.
The Aztecs managed…but they had 300,00 people. There are now some 21 million.
At a roundabout along the city’s wide downtown boulevard, the gilded Angel of Independence, looks over a sea of traffic from atop of a Corinthian column. The ribbon cutting for the monument was in 1910 with the 9 shallow steps leading up to it. In the hundred plus years since then the whole neighborhood around the monument sank requiring an additional 14 large steps to be added to the base for the monument to be connected to the street. Pedestrians walk up hills that were once flat lake beds, but have given away. Buildings are leaning in various directions, doors no longer align with their frames.
The government acknowledges that nearly 20% of Mexico City’s residents can’t count on getting water from their taps everyday or worse. The director of the water system thinks that climate change will mean more intense rains leading to flooding, and more intense droughts. If it stops raining in the reservoirs they will face a disaster as it would be impossible to truck in water for 21 million people.