Mexico Life
A Tlaloque rainwater capture system in San Gregorio Atlapulco, Xochimilco A Tlaloque rainwater capture system in San Gregorio Atlapulco, Xochimilco. Cate Cameron

Through a non-profit, Tlaloc the rain god provides water in CDMX and beyond

Isla Urbana has installed 7,500 rainwater capture systems, called Tlaloques

An ingenious rainwater harvesting system developed by a Mexico City organization is helping the most marginalized communities of the city have access to clean water.

“Tlaloques were helpers of the rain god, Tlaloc,” Nabani Vera Tenorio told Mexico News Daily, explaining the name behind the system developed by Isla Urbana.

As the Mexica cosmology goes, Tlaloques were children that Tlaloc sent around the world with clay pots full of water. When Tlaloc gave the order, the Tlaloques would smash the pots together, creating thunder and letting water rain down upon the earth from above.

It is the perfect name for the system created by this highly skilled and dedicated organization to collect and filter rain. After all, these filters are helping Tlaloc to make the most of his abundant offering.

Anyone who has spent time in Mexico City will know that this bustling capital can see more rainfall in an hour than many places see in a week. The streets flood, there is traffic chaos and the storms can have an almost apocalyptic feel.

And with a rainy season that lasts for many months, it seems incongruous that a city with so much rain should suffer from constant water shortages. Residents in even the most connected areas sometimes go without water for days at a time and some 250,000 people have no access to piped water at all.

Perhaps the fact that around 21.5 million people live in this city built on a lake goes some way to explain the supply-demand issue. The population, including the greater city limits, has grown from around 13 million in 1980 to 21.5 million in 2018, putting an obvious strain on the water supply.

Seventy per cent of Mexico City’s water comes from underground aquifers but as they are being drained to meet the city’s water needs, Mexico’s capital is sinking. In the last 100 years alone the city has sunk some 10 meters.

In addition, Tenorio explained that an estimated 40% of the city’s water is lost due to leaks in the old, sputtering underground pipes. This means that for every liter of water used another 40 milliliters is lost.

Isla Urbana has been working to find solutions to Mexico’s water problems since 2009. It all started with a degree thesis and a woman called Clara.

Renata Fenton and Enrique Lomnitz were studying for degrees in industrial design when they came upon the idea of working on a project that would help their home city. For research they talked to the Señora Clara, who lived in Ajusco on the outskirts of Mexico City, to find out what her needs were.

Happy homeowners of a Tlaloque installed in Xochimilco.
Happy homeowners of a Tlaloque installed in Xochimilco.

Of the many problems she faced, the lack of access to water was the most pressing and the one that Fenton and Lomnitz decided to focus on. An idea that began with a single house has now made a big impact in the city and beyond: 7,500 rainwater harvesting units have been installed across the country, close to 54,000 people helped and some 333 million liters of water saved so far.

Tenorio explained that Mexico City is the perfect environment for the system. The flat roofs and the fast and heavy rainfall make conditions for collection perfect. “The first volume of water cleans the sky and the roof,” explained Tenorio, which allows for cleaner water to fill the cistern and as long as the system is maintained correctly, it provides water that is of drinking quality.

While there are a few variables, it is possible that a family of four that has a good size roof and saves water can have enough for the whole year, Tenorio said. That means one entire family is not draining the average 920 liters of water per day from the aquifer.

The system not only saves water but also drastically changes the quality of life of the recipients, who no longer have to rely on water delivery trucks or walk each day to collect water for their homes.

Isla Urbana is focusing its efforts on the areas of the city that have no access to municipal water. Remote parts of Tlalpan, Milpa Alta and Xochimilco are of particular focus.

But a system cannot be installed and left. It requires work and maintenance on the part of the homeowners. Residents who are interested in capturing their rainwater have to attend a mandatory workshop to understand their role in the upkeep of the Tlaloque.

In some cases, they are also asked to pay a small amount for the systems, a well-researched and proven way of creating more engaged recipients. It is important that the systems are being used properly and effectively for the benefit of the residents and the city as a whole, so the Isla Urbana team provides yearly maintenance and is always on hand for questions and queries.

The Isla Urbana team.
The Isla Urbana team.

What about standing water and mosquitoes? The systems are mosquito-proof, tightly sealed and protected with mosquito netting to avoid the possibility of the spread of disease.

As well as supplying the rainwater capturing systems, Isla Urbana sees it as its duty to educate citizens about water usage. With a project called La Carpa Azul or The Blue Tent, the plan is to make Mexican citizens active rather than passive water users.

To do this they work with communities and with schools, offering theater productions and art projects related to water.

Tenorio described how positive acts like coming together as a community and painting a gray wall with a mural of an “axolotl watering the houses and seeing them bloom, for example” creates a more open and enjoyable space from which to talk about and think about water.

Isla Urbana’s work is proven to create resilience too. Last year’s September 19 earthquake left a large number of people struggling without water for weeks. In San Gregorio Atlapulco, a remote part of Xochimilco where Isla Urbana works, the houses with the Tlaloque rainwater systems continued to have water after the earthquake while everyone else did not.

“They were the only ones who had water and they started to share it with their neighbors,” Tenorio explained. The earthquake also motivated the team to create an emergency drinking water system to be prepared for any future emergency.

As well as providing the Tlaloques free of charge or at a very small fee to marginalized communities, the organization also runs a business entity that sells the systems to anyone looking to live a more sustainable life.

The small profit made from selling the products is used to help fund the operations of the social side of the business.

While the kits cannot be installed in buildings higher than about three floors (because the water collected would simply not be enough to serve all the apartments) Isla Urbana does sell household kits that can be easily installed and help residents use up to 50% less water.

Despite the many challenges the city faces with regard to water, Isla Urbana feels positive about the future. The new government is already indicating it wants to collaborate with the organization to solve those problems, calling on Isla Urbana’s expertise and its new, alternatives ways of dealing with the city’s water shortages.

By the end of the year, Isla Urbana’s goal is to have 10,000 water-harvesting systems installed and Tlaloc’s little helpers will continue to provide water for those who need it most.

To find out more about the work that Isla Urbana is doing across Mexico City and beyond, check out their website.

Susannah Rigg is a freelance writer and Mexico specialist based in Mexico City. Her work has been published by BBC Travel, Condé Nast Traveler, CNN Travel and The Independent UK among others. Find out more about Susannah on her website.

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