Photo: Isla Urbana Facebook Post 9/25/20

By Julia Fine, ODP Contributing Writer

The current global pandemic has effectively made water access even more crucial, as lack of clean water exacerbates the spread of COVID-19. One non-profit in Mexico City, a place with an immense amount of rainfall yet a scarcity of potable water for the city’s 20 million residents, is trying a novel way to collect water. As Alan Grabinsky reported for The Wall Street Journal, “The city government had teamed up with local nonprofit Isla Urbana to install 100,000 of its rainwater-harvesting systems in the districts of Xochimilco and Iztapalapa.”

Why This Matters: Collecting rainwater is, of course, a “centuries-old practice,” as Grabinsky noted. But the NGO’s system is “cheaper, faster and easier to install than most existing technology.” Such technology could provide a potential solution to the water crisis in Mexico City in a way that does not harm nor infringe upon the rights of indigenous groups, unlike the hydro-engineering projects that have been pursued there.

A Wet Desert

As sociologist Manuel Perló, told the WSJ, “Mexico City’s case is tragic because, unlike other cities, it is located on a region where water abounds.” Indeed, the city has “more rainy days than London,” but “suffers shortages more in keeping with a dessert, making the price of each litre among the highest in the world – despite its often dire quality.”

Why is this the case? According to Perló, “the resource has been mismanaged.” As the WSJ writes, “In Mexico City when it rains, it storms, but the water mixes with the sewage and cannot be used.” Another reason for this water loss, says Perló, is that “most of the city’s water is pumped from dams up to 125 miles away, and 40% is lost through leaks in pipes and containers.” This means many denizens of the city’s poorest areas do not have sufficient access to water, as a 2018 NPR piece reported.

A New Spin on an Old System

NGO Isla Urbana believes they can help change this unjust system. Under their model of collecting rainwater, pipes take water running off the roof. Then, the system removes leaves and other debris. Next, the water “goes through a patented filter called the Tlaloque 200 before being collected in a tank.” The water that comes out isn’t quite potable but can be if items like a purifier and carbon filter are added on.

According to Grabinsky, “It remains to be seen how durable the system is—an important consideration because maintenance is crucial for good water quality.” This is not the only impediment to the implementation of this system. As the WSJ noted, “One obstacle to broader global implementation of rainwater harvesting is the belief by citizens, health officials and utilities that it is less hygienic than centralized city water systems.” And, of course, none of this is possible if the rain dries up. Nevertheless, this new method of rainwater harvesting could provide a potentially positive outcome for Mexico City’s 20 million residents.

To Go Deeper: Read this 2015 piece about Mexico City’s water crisis, which takes you “from source to sewer.” And to read more about Isla Urbana’s work, click here.