Água Carioca is a low-tech, flexible and adaptable system, improving water quality and reducing water demand locally using 3 elements – rainwater harvesting, septic tanks and constructed wetlands. Treatment of waste water at source reduces the CO2 impact of open sewage as well as dramatically improving local conditions. Quick and relatively inexpensive to implement, the system works at multiple scales, from a building to whole neighborhoods and holds the ability to transform an entire city.

10–15 houses, each fitted with a rainwater collection and septic tanks, share a communal wetland. The elements are inserted into the existing urban fabric, exploiting under-used space without causing mass disruption. On sloped areas, wetlands can become terraces, alleviating the threat of landslides. Initiated by public funds, the system is implemented and operated collaboratively, bringing together top down strategy with bottom up action. It deliberately engages hard-to-reach, local stakeholders.

Four designs, addressing urgent needs, working across multiple scales and diverse urban contexts.

Live classrooms: education and understanding of the water cycle in schools will multiply efforts.

A new relationship and shared story around water is created, improving quality of place.

As the project scales up, local benefits become paired with city and regional benefits.

Following a successful pilot in 2016, the project is now working to deliver a neighborhood project.

Eco-technology: constructed wetlands are at the core of the project, ensuring a robust performance.

Água Carioca demonstrates a way of working, to enhance acceptance and agreement among stakeholders.

The project builds bridges between actors, capturing value and empowering local communities.

Winners of the LafargeHolcim Awards Bronze 2017 for their Sanitation system in informal communities of Rio de Janeiro, Brazil (l-r): Eva Pfannes y Sylvain Hartenberg from Ooze Architects, Rotterdam, Netherlands.

Presentation to winners of the LafargeHolcim Awards Bronze 2017 for their Sanitation system in informal communities of Rio de Janeiro, Brazil (l-r): Sergio Mauricio, Commercial Director, LafargeHolcim Brazil; Eva Pfannes y Sylvain Hartenberg from Ooze Architects, Rotterdam, Netherlands; and Oliver Osswald, Member of the Executive Committee, LafargeHolcim.

Winners of the LafargeHolcim Awards Main prizes (l-r): Jonathan Franklin, Exxpon and Sol Camacho Davalos, Raddar, Brazil (Silver); Loreta Castro Reguera and Manuel Perló Cohen, Universidad Nacional Autónoma de México (Gold); Eva Pfannes and Sylvain Hartenberg from Ooze Architects, Netherlands (Bronze).

Eva Pfannes showed how, with the Bronze Award winner, wastewater will no longer pollute natural waterways, but will be treated using constructed wetlands as an effective and proven treatment to clean wastewater.

Project team.