One of the world’s largest cities has almost run out of water: only a few months left

Years of abnormally low rainfall, longer dry spells and high temperatures have increased pressure on the water supply in the Mexican capital of Mexico City. Authorities have imposed restrictions on water pumped from reservoirs.

“Several areas have suffered from water shortages for weeks, and the rains are still four months away,” said Cristiane Dominguez Sarmiento, an atmospheric scientist at the National Autonomous University of Mexico.

Politicians are trying to contain the problem, but the situation has reached such a critical level that Mexico City could be on the verge of “Day Zero” within months, with taps running dry in large areas of the city.

Densely populated Mexico City was built on clay-rich soil that is now sinking, and is prone to earthquakes and highly vulnerable to climate change. The Aztecs chose this site to build their city of Tenochtitlan in 1325, when it was a series of lakes. They were built on the island, expanding the city in breadth, constructing networks of canals and bridges to handle water.

But at the beginning of the 16th century, the Spaniards destroyed most of the city, drained the bottom of the lake, filled up the canals and cut down the forests. They viewed “water as an enemy that must be defeated in order for the city to prosper,” according to architect José Alfredo Ramírez, a decision that created the path to many of Mexico City’s modern problems.

About 60 percent of Mexico’s capital’s water comes from an underground aquifer, but its extraction is so excessive that the city is sinking into the ground at a rate of about 20 inches a year, according to recent studies.

In October 2023, the country’s national water commission, Conagua, announced it would limit water supplies by 8 percent “to ensure the supply of drinking water to the population in conditions of severe drought.” Just weeks later, officials significantly tightened restrictions, cutting the system’s water supply by nearly 25 percent, blaming extreme weather conditions.

“It will be necessary to take measures to be able to distribute the water that is available to ensure that it does not run out,” Conagua CEO German Arturo Martinez Santoyo said at the time.

About 60 percent of Mexico is experiencing moderate to exceptional drought, according to a February 2024 report. Almost 90 percent of Mexico City is suffering from severe drought, and the situation will worsen as the rainy season is still months away.

“We are roughly in the middle of the dry season, and temperatures are expected to rise steadily until April or May,” said specialist June Garcia-Becerra.

Climate impacts have collided with the growing pains of a fast-growing city. Experts note that as the population grows, the centralized water supply system lags behind.

The water crisis has sparked fierce debate over whether the city will reach “day zero,” when water levels in the Cootzamala mining system drop so low that it cannot supply water to the city’s residents. In early February, local media widely reported that an official from the Conagua branch had said that without significant precipitation, “day zero” could occur as early as June 26, 2024.

But since then, authorities have tried to reassure residents that there will be no Day Zero, and at a press conference, Mexican President Andrés Manuel López Obrador said work was underway to solve water problems. Mexico City Mayor Martí Batres Guadarrama said the news about “Day Zero was fake, spread by political opponents.”

“Mexico City may run out of water,” says Sosa-Rodriguez. According to her, this does not mean a complete collapse of the water supply, because the city does not depend only on one source. It won’t be the same as Cape Town, South Africa, when the city came dangerously close to drying out completely in 2018 after a severe multi-year drought.

“Some groups will still have water,” the specialist notes, “but most people will not.”

Sosa-Rodriguez said she has been warning officials about the dangers of a zero day in Mexico City for nearly a decade. She also proposed solutions: Improved wastewater treatment would both increase water availability and reduce pollution, while rainwater harvesting systems could capture and recycle rainwater and allow residents to reduce their dependence on the mains water supply or water trucks by 30 percent.

In a statement, Conagua said it is undertaking a three-year project to install, develop and improve water infrastructure to help the city cope with cuts to the Coetzamala system, including adding new wells and commissioning a water treatment plant.

But in the meantime, some residents are forced to cope with food shortages, while others – often in wealthier enclaves – remain largely unaffected.

“There is a clear disparity in access to water in the city, and it has to do with people’s income,” Sosa-Rodriguez tells CNN. “While Day Zero may not have arrived yet for all of Mexico City, some areas have been struggling with it for years.”

A resident of the Tlalpan city district, Amanda Martinez, in an interview with an American publication, shared stories that for local residents, water shortages are not something new. She and her family often have to pay more than $100 for a tanker of water from one of the city’s water trucks. But it’s getting worse, she says. Sometimes more than two weeks can go by without water, and she fears what might happen next.

Another city resident, Alejandro Gomez, has not had proper running water for more than three months. According to his observations, sometimes it is served for an hour or two, but only in a thin stream, which is barely enough to fill a couple of buckets. Gomez doesn’t have a large storage tank, so he can’t supply water by truck – there’s simply nowhere to store it. Instead, he and his family make do with what they can buy and save.

“Water shortages are not uncommon in this area, but this time is different,” Gomez said. — Right now we have such hot weather. This is even worse, everything is much more complicated.”