$2B mega drainage project to save Mexico City from floods during rainy season

World Today

Near Mexico City, construction crews are working around clock – underground — excavating and lining a 62-kilometer long tunnel that will play a key role in Mexico City’s much needed drainage system. CGTN’s Franc Contreras gained rare access to the $2 billion dollar mega-infrastructure project.

It is located 90 meters (295 feet) below the surface of the earth; so big you can drive a train through it. This tunnel is the last and final section of a mega works project that will become the drainage system for Mexico City, the most populated city in North America.

Over the past 10 years, tunnel digging crews, supervised by Mexico’s National Water Commission, have been working around the clock, seven days a week, deep under the surface of the earth.

Engineer Mario Andres Terres supervises a section of the tunnel construction. He’s helped manage the project and said the biggest challenge right now is breaking through millions of tons of solid volcanic rock. But it is not a problem with modern technology.

“Basalt is a commonly known rock that comes from volcanic lava. The fact that it’s so hard makes it difficult to cut. Our machines are designed to break this tough rock into chips and turn it to gravel,” Terres said.

The ancient Mexican capital was originally built nearly 700 years ago upon a system of lakes connected by water canals. Water management has always been a critical part of life here.

During the summer, heavy rains regularly bring massive flooding, and this inundation of water has plagued Mexico City for decades.

Another engineer managing this project, Jose Li Espinosa, says once the drainage tunnel is operating, flooding will no longer be a problem.

“This tunnel will have the capacity to drain all rain water before it turns to floods each year. And it will be connected to the other parts of Mexico City’s existing drainage system of water collection sites and tunnels,” Espinosa said.

The underground infrastructure project is scheduled for completion in July, just in time for the rainy season.