Rainwater Harvesting Expands Access in Mexico City

Non-profit Isla Urbana, founded in 2009, installs roof-capture systems that store 2,500 litres of rainwater for household use and a 1,100-litre tank for gardening. By 2026 the organization has equipped roughly 2,000 public schools nationwide and aims to reach one million low-income families by the following year. Nationwide, 17 % of households struggle to meet basic water needs, and 74 million people (57 % of the population) lack safe water, according to the National Health and Nutrition Survey. Systems are also sold privately, often to municipal governments, to fund the nonprofit work.

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Co-founder Enrique Lomnitz explains that Isla Urbana “creates rainwater harvesting systems that provide mainly low-income households with sustainable water access for five to eight months of the year.” The organization operates as a nonprofit for low-income installations while selling systems to generate revenue, supplemented by grants and donations from Mexico, the United States, and other donors. Mexico’s national water-access policy, approved in 2025, enshrines the human right to water and prioritises domestic consumption over industrial use, yet droughts linked to the climate crisis continue to strain supplies.

The Guardian

• “I can grow vegetables,” — Ana Aparicio Bahena, resident

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• “The intention is to build the foundations for a much more water-conscious and water-capable population, with useful knowledge about how they could harvest and store water safely at home,” — Enrique Lomnitz, co-founder, Isla Urbana

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• “It has got us out of trouble several times,” — Dora Napolitano, textile artist

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• “These systems can mitigate water scarcity, especially during rainy seasons, as well as address social and water vulnerability,” — Judith Domínguez, research professor, El Colegio de México

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• “The water harvesting system really changed our lives. Now we are able to dream and have more time,” — Ana Aparicio Bahena

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Aparicio Bahena, whose home lacks a municipal water connection, now uses a small plastic filter to make harvested greywater safe for drinking, eliminating a two-hour daily water-collection trek. Napolitano, who purchased a 5,000-litre system for 40,000 pesos in 2018, cites the system as a “life-saver” during severe droughts, even though she still receives tap water. Experts note that while the systems require regular filter maintenance to prevent health risks, they provide a low-maintenance, household-level solution that can reduce reliance on intermittent municipal supply.

The Guardian