Isla Urbana - Urban Rainwater Harvesting
Mexico City, Mexico · 2009 · Isla Urbana (Mexico), in collaboration with local communities, schools and public authorities at municipal, state, and federal levels.
Isla Urbana has fundamentally changed how rainwater is understood and managed in Mexico. Rather than viewing rainfall as stormwater to be removed through drainage systems, the organization has demonstrated that it is a strategic local resource capable of strengthening water security, improving climate resilience, and complementing conventional urban water infrastructure. Through more than 46,000 installed systems, Isla Urbana has benefited over one million people, providing reliable access to locally harvested water for households, schools, healthcare facilities, and communities. Depending on local conditions, these systems can supply users with six to nine months of water autonomy each year, reducing dependence on groundwater extraction, municipal supply systems, and water truck deliveries while lowering environmental impacts associated with water transport and energy-intensive pumping. Beyond infrastructure, Isla Urbana has helped reshape public policy by demonstrating that decentralized rainwater harvesting is a viable, scalable, and cost-effective strategy for urban water management. Its experience contributed directly to the implementation of Mexico City's Cosecha de Lluvia program and has strengthened the integration of rainwater harvesting into broader strategies for climate adaptation, resilience, and sustainable development. Perhaps its most enduring contribution has been cultural. Through community engagement and initiatives such as Escuelas de Lluvia, Isla Urbana has helped thousands of families, students, teachers, and public institutions develop a new relationship with water—recognizing rain as a valuable local resource rather than a problem to be drained away. This combination of technological innovation, education, institutional collaboration, and policy influence has positioned Isla Urbana as one of the world's leading examples of decentralized rainwater harvesting and a highly replicable model for water-stressed regions.
Highlight
From Rain to Resilience: Building Water Autonomy Through Decentralized Rainwater Harvesting.
Extended description
Across Mexico, water security is increasingly threatened by climate change, groundwater depletion, rapid urbanization, aging infrastructure, and growing demand. Nowhere is this challenge more evident than in Mexico City, one of the world's largest and most water-stressed metropolitan areas. Although the region receives significant annual rainfall, much of this valuable resource is diverted into drainage systems, contributing to flooding while millions of residents continue to experience unreliable access to water.
Founded in 2009, Isla Urbana emerged to challenge this paradox by demonstrating that rainwater should be recognized not as runoff to be discarded but as a strategic local resource capable of strengthening water security and climate resilience.
Over the past fifteen years, the organization has developed an integrated model that combines technological innovation, decentralized infrastructure, environmental education, community participation, and public policy collaboration. This holistic approach has enabled rainwater harvesting to evolve from isolated pilot projects into one of the most significant decentralized water management strategies in Latin America.
At the heart of Isla Urbana's model are rainwater harvesting systems designed for households, schools, healthcare facilities, community buildings, and public institutions. Each system captures rainfall from rooftops, diverts the contaminated first flush, filters sediments, stores water in cisterns, and incorporates treatment technologies appropriate for domestic use. Depending on rainfall patterns, storage capacity, and household demand, these systems can provide between six and nine months of water autonomy, significantly reducing dependence on municipal water networks, groundwater extraction, and water truck deliveries.
Continuous technological innovation has been central to the organization's success. Isla Urbana has developed proprietary components—including the Tlaloque and Tlaloquito first-flush devices—that improve water quality by automatically diverting the initial runoff carrying dust, debris, and contaminants accumulated on rooftops. These innovations increase reliability while minimizing maintenance requirements, allowing systems to operate efficiently in diverse climatic and social contexts.
Equally important is Isla Urbana's commitment to social innovation. Every installation is accompanied by community engagement, technical training, maintenance support, and environmental education to ensure long-term adoption and local ownership. Through initiatives such as Escuelas de Lluvia (Rain Schools), educational institutions become living laboratories where students, teachers, and families learn about the urban water cycle, aquifer conservation, climate adaptation, and sustainable water management while directly benefiting from harvested rainwater.
The organization has also played a transformative role in public policy. Its technical expertise and years of field implementation informed the development of Mexico City's Cosecha de Lluvia program, demonstrating that decentralized rainwater harvesting can operate effectively at metropolitan scale and complement centralized water infrastructure. Today, Isla Urbana's model is recognized nationally and internationally as an example of how distributed water systems can improve resilience, equity, and sustainability.
Beyond Mexico, Isla Urbana has implemented projects in other Latin American countries, contributing to the growing adoption of decentralized rainwater harvesting as a practical solution for regions facing increasing water stress under climate change.
Demonstrated metrics
Since its founding in 2009, Isla Urbana has generated measurable impacts in water security, climate resilience, environmental education, and sustainable urban development.
Reported impacts include:
More than 46,000 rainwater harvesting systems installed.
More than 1 million people benefited.
456,492,647 liters of rainwater captured annually.
Household systems capable of providing six to nine months of water autonomy, depending on local rainfall conditions and storage capacity.
Large-scale implementation across households, schools, healthcare facilities, community buildings, and public institutions.
Proprietary technologies that improve water quality, operational efficiency, and long-term reliability.
Successful collaboration with governments to integrate decentralized rainwater harvesting into public water management strategies.
Real impact
Isla Urbana has helped shift rainwater harvesting from a niche environmental practice toward a scalable water-security strategy in Mexico. Through more than 46,000 installed systems, it has expanded access to locally harvested water for households, schools, healthcare facilities, and communities, particularly in areas with unreliable water supplies.
Beyond infrastructure, Isla Urbana has influenced public policy by demonstrating that decentralized rainwater harvesting can complement conventional urban water systems. Its experience contributed to Mexico City's Cosecha de Lluvia program and has strengthened the integration of rainwater harvesting into climate adaptation, resilience, and sustainable water-management strategies.
Through community engagement and initiatives such as Escuelas de Lluvia, the organization also combines infrastructure with education and local capacity-building, helping communities recognize rain as a valuable resource while supporting long-term system use and maintenance.
Implementation location & date
Mexico, with additional projects in Latin America. Founded in 2009, Isla Urbana has expanded from community-scale projects to household, school, institutional, and government-led rainwater harvesting programs across Mexico.
Similar cases elsewhere
Similar large-scale approaches include Brazil’s Programa Cisternas, supporting household and community rainwater storage since 2003, and India’s Jal Sanchay Jan Bhagidari, which scales community-based rainwater harvesting.