Facing a severe water crisis, Mexico City, a vast metropolis with an approximate population of 22 million, contends with a range of challenges. These include geographical obstacles, unplanned urban sprawl, and aging infrastructure susceptible to leaks, all heightened by the impacts of climate change. Abnormally low rainfall and years of drought have drained the city’s reservoirs. Local officials have already begun imposing severe monthslong restrictions as the water system approaches its limits.
The problems in Mexico City’s water supply began with aggressive public policies to spur development. Government programs enticed residents to move from shanty towns on the city’s periphery into planned communities where cookie-cutter apartments and housing developments sprung up, often without proper oversight. The result was chaotic growth that led to many buildings and neighborhoods with minor in common, many constructed without permits.
This rapid expansion strained the city’s complex and aging hydraulic system. The system consists of interconnected dams and reservoirs supplying drinking water to 80% of the population. But the city’s reservoirs are at or near their lowest levels in decades because of drought and growing water demand.
As a result, officials have been forced to cut consumption by 40% and impose severe restrictions on the amount of water pumped from the city’s reservoirs and to residents. This is set to continue until the rainy season begins, which is still three months away.
Meanwhile, the city’s sewage system is grossly inefficient. Its 21 small sewage treatment plants only effectively handle about a tenth of the city’s sewage, and most of the rest flows directly into Mexico City’s waters. This pollutes the city’s water with feces and other waste, making it taste or smell bad.
The problem is compounded by a series of failures in the city’s distribution network. Leaks are a significant issue: water is lost in pipes at 12,000 liters per second or over a billion liters yearly. The city’s aging pipes are also susceptible to corrosion, reducing efficiency.
Fortunately, there are solutions. Some are relatively simple, such as repairing and sealing leaks. Others are more complex, such as replacing the old water-pipe network with a new one designed to resist corrosion and other stresses better.