As severe drought parched the Valley of Mexico earlier this year, news outlets began a countdown to a total failure of the water system. Reservoirs more than 100 kilometers away from Mexico City were at dangerously low levels and some areas already were facing acute shortages. Tanker trucks loaded with potable water sloshed down residential avenues to deliver emergency supplies. 

Without ample rain, “Day Zero” would theoretically arrive in June. But that darkest fear of urban planners, politicians, residents and academics never came to pass. How did one of the world's largest cities avert all-out disaster?

What saved the metropolitan area’s 22 million residents from a calamitous water-system collapse was a combination of just-in-time rainfall, urgent political pressure and underground reserves that saw the city through the worst. The drawn-out crisis vaulted the region’s aging infrastructure to television screens and newspaper front pages, spurring everyday chilangos — as capital dwellers are known — to wonder if years of neglect and indifference by politicians would change.

“The model of water management in Mexico City is no longer functioning, and it’s important that we think of long-term solutions,” said Rodrigo Gutiérrez Rivas, a researcher focused on constitutional and water rights at the National Autonomous University of Mexico, or UNAM. “Water became one of the main issues during the campaign cycle and now that it's won by a wide margin, the government of Mexico City has a huge opportunity to transform the model.”

Mexico City 'Day Zero' Never Came: How the City Avoided Running Out of Water

With just-in-time rain and a looming presidential election, Mexico City never reached ‘Day Zero.’ But the politicized threat helped propel water infrastructure as a priority policy issue.

^{Maya Averbuch (Bloomberg)}