Mexico City Is Sinking While Also Running Out of Drinking Water

Mexico City is sinking by an estimated one meter (3.2 feet) every year, while it simultaneously faces a water crisis.

The ancient Aztecs, who were conquered by the Spanish under the command of conquistador Hernán Cortés in the 1500s, were the first to build a city in the region. As they constructed their capital Tenochtitlán on top of the valley's large lakes, they left the natural water supply intact surrounding the city. In periods of heavy rains, the city would flood but this was managed by a dike system.

After the Spanish conquered the indigenous population, they quickly expanded their empire over the next few centuries, depleting the surrounding lakes almost completely, according to NPR. After Mexico became an independent nation in 1810, the surface water near the city was more or less depleted. The city pipes in some 30 percent of its water from distant lakes and rivers today, but an increasing portion of the capital's water also comes from a large aquifer underneath the city, causing it to sink lower year after year.

The Mexico City skyline is seen through the haze from the Latinoamericana Tower on June 26, 2012. A significantly larger population, as well as climate change, are making the city's problem more serious. John Moore/Getty Images

"Everywhere they pumped up groundwater from the boreholes, the ground sank. Without the water there, the sediments that the city was built on compressed a lot more," Eddie Bromhead, a geotechnical engineer at U.K.-based Kingston University, explained to The Guardian.

"It's a historic mistake the city has had to pay for more than 500 years," Ramón Aguirre Díaz, who runs Mexico City's municipal water system, told NPR. He explained that twice as much water is pumped out of the aquifer as is replaced annually. "We are depleting volumes of water that took hundreds, thousands of years to store. Sooner or later it will run out," he said.

Although the ancient Aztecs managed the city and their resources better than the Spanish, experts pointed out that a significantly larger population, as well as climate change, are making the problem more serious.

"The Aztecs managed," Loreta Castro Reguera, a Harvard-trained architect who specializes in the sinking ground in Mexico City, told The New York Times last year. "But they had 300,000 people. We now have 21 million."

Some in poorer neighborhoods of the Mexican capital have already felt the impact of water shortages, telling NPR that during dry seasons no water comes from their taps. Even during the rainy season, they may only get an hour of water per day.

Picture taken on October 2, 2017, showing the Metropolitan Cathedral at Zocalo Square in Mexico City. This structure has been slowly sinking for hundreds of years, according to a 1999 report from BBC. ALFREDO ESTRELLA/AFP/Getty Images

Photos of iconic Mexico City buildings clearly show that the structures are leaning as the city sinks. In 1999, BBC reported that Mexico's Metropolitan Cathedral has been sinking for hundreds of years, leading a group of architects to try to "keep the building upright."

For years, many have been pessimistic that the water problems and the city's future can be resolved. "There's no fixing it," journalist Andrea Noel told Eco Watch in 2016. "The city needs to find a way to figure out their water problem. They really need to look into alternatives like collecting rainwater, which makes so much sense in a city like this, which gets so much rainfall every year."

Expressing similar sentiments, Aguirre Díaz told NPR that Mexico City won't see "the 22nd century" if it doesn't address its problems soon.

Early this month, however, mayor-elect Claudia Sheinbaum pledged a $370 million investment in the city's water department. "With this, we'll take action to improve water distribution services across the city," Sheinbaum said via Twitter.