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MODULAGUA develops an inclusive, modular system that treats and reuses wastewater and stormwater to irrigate green urban areas and protect natural waterways in Mexican cities.

Facts

  • Project type PfW Subsidy Project
  • Country Mexico
  • Location Santa Cruz Xoxocotlán, Oaxaca
  • Partners Santa Cruz Xoxocotlán Town Council; CIIDIR Oaxaca; BD+P (Becandavila), together with Colubris Cleantech B.V
  • Themes Wastewater reuse, stormwater management, urban greening
  • Duration 2025, 2026
  • SDGs SDG 6, SDG 11, SDG 13

Water challenges in Mexico

Santa Cruz Xoxocotlán needs to find ways to discharge untreated wastewater into natural waterways to avoid urban flooding. The inability to capture stormwater and the lack of sufficient green spaces is threatening public health and ecosystems. Besides that it intensifies the Urban Heat Island effect, in which cities – because of the amount of concrete – become significantly warmer than their surroundings. The combination of water pollution, flooding, water scarcity and rising urban temperatures calls for an integrated approach.

The Modulagua project is a collaborative water infrastructure initiative being implemented in the municipality of Santa Cruz Xoxocotlán, Oaxaca. This strategy focuses on the treatment of wastewater and stormwater, with the aim of modernizing the community’s environmental services through innovative technology. The project will explore how wastewater and stormwater can be captured, treated and reused locally, while also creating and sustaining a green urban corridor.

The objectives

MODULAGUA will conduct a feasibility study for an integrated water-management system in Santa Cruz Xoxocotlán. The system will combine a Flotation Bio Reactor with Nature-based Solutions to treat wastewater and stormwater for urban reuse. The idea is that the untreated wastewater will be discharged into natural waterways. Capturing stormwater could reduce urban flooding and produce treated water for irrigating green urban areas.

The approach

Biofilter and a constructed wetland: A biofilter will capture and pre-treat stormwater as it passes through planted layers of soil, sand and gravel. The constructed wetland then provides a final stage of natural purification, using plants, soil and microorganisms to further improve water quality before reuse for irrigation. Any surplus water is discharged into a natural waterway, in this case the Atoyac River. Together, these components form a modular system that can be adapted to the urban context and expanded as local needs evolve.

This initiative forms part of my commitment to environmental sustainability, the modernization of the region and the comprehensive improvement of public services.

Nancy Benítez Zárate
Mayor

The team

  • The Santa Cruz Xoxocotlán Town Council, led by the mayor, Nancy Benítez Zárate;
  • CIIDIR Oaxaca (the IPN’s Interdisciplinary Centre for Research into Comprehensive Regional Development);
  • BD+P (Becandavila), together with Colubris Cleantech B.V., Dutch companies specializing in environmental and water treatment solutions. The project consortium brings together expertise in water treatment, Nature-based Solutions, urban development and stakeholder engagement.

Expected outcomes

The anticipated outcomes of this project include:

  • A feasibility study for an integrated wastewater and stormwater treatment system in Santa Cruz Xoxocotlán.
  • An assessment of the technical, environmental, financial and social conditions for implementation.
  • A conceptual design combining an FBR, biofilter and constructed wetland.
  • Identification of opportunities for treated-water reuse in urban green areas.
  • Stakeholder engagement with local authorities, communities and other relevant users.
  • An implementation roadmap supporting future investment, demonstration and scale-up.

Why it matters

MODULAGUA offers a replicable model for Mexican cities facing water pollution, flooding, water scarcity and a lack of green space. By treating and reusing local water flows, the approach can reduce pressure on natural waterways while supporting cooler, greener and more climate-resilient urban environments. Its modular design allows the system to adapt to different neighbourhoods and city contexts.

Innovation in Progress series

MODULAGUA features in Partners for Water’s ongoing Innovation in Progress series. Throughout this series, Partners for Water closely follows a selection of projects that have received a Partners for Water subsidy, from start to finish. Over the coming years, these projects will take you with them on their journey of testing the feasibility or application of innovative solutions to enhance water security abroad — including their processes, collaborations with local partners, potential solutions, and the struggles, challenges and lessons learned along the way.

 

Follow the MODULAGUA Journey

Get involved

This project was funded through the Partners for Water subsidy scheme. Discover more ways to get involved with Partners for Water

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