Mexico City, one of the world's largest cities, is facing a severe water crisis due to years of drought exacerbated by climate change. The Cutzamala water system, which supplies around 25 of the city's water, is at around 39 capacity - a historic low level. Restrictions on water usage from Cutzamala have been tightened in recent months, but some experts warn the city could reach "day zero" - when the system cannot provide any water - in the coming months if significant rain does not arrive. Long-term solutions like infrastructure upgrades, leak prevention, and nature-based approaches are needed alongside demand management.