The water system that fuels Mexico City could run out in a month, an event locals call "Day Zero."Getty ImagesMexico City could run out of drinking water by June 26, an event locals call "Day Zero."Three years of low rainfall and high temperatures have worsened the city's water crisis.The Cutzamala water system, which provides water to millions, operates now at 28% capacity.Experts say that Mexico City could run out of drinking water by the end of June, an event locals call "Day Zero."Mexico City has long struggled to bring water to its millions of residents, but three consecutive years of low rainfall and high temperatures have created a serious emergency.The Cutzamala water system — a series of treatment plants, reservoirs, and canals that provide water to tens of millions of people — is running dry.Conditions are so bad that the North American Drought Monitor classified the federal district containing Mexico City as "severe" on April 30.