Careiro da Várzea
The city’s neighborhoods along the Negro River and its tributaries-Igarapés- are defined by the annual river level changes, where water levels can rise and fall by up to ten meters. Over generations, residents responded to this rhythm by developing palafitas– wooden stilt houses elevated above seasonal floods- and marombas- elevated wooden walkways. Our proposed design interventions aim to preserve these communities in place while addressing environmental hazards associated with the floodplain and improving access to essential sanitation, water, and community services.
4 Household toilets and Communal Wastewater Treatment Plan
Palafita homes across the Amazon lack appropriate sanitation technologies due to the challenges imposed by the changing fluvial nature of their environment. This compromises their health and the quality of the environment in which they live.
In image 4, we propose installing an elevated, low-cost toilet and hand-washing facility, leveraging gravity from rainwater collection, for each house in palafita communities, thus providing safety and privacy for all residents. The roof rainwater collection and toilet elevation ensure proper gravity flow of water within the piped system. In addition, the rainwater collection tank can supply water for handwashing.
5 Floating farms
Our project aims to re-center the city’s waterways as a key resource for urban life vitality. A central aspect of our proposal is the implementation of floating farms (image 5), which seek to reconnect the residents of the palafitas to their waterways, transforming them into productive communal landscapes.
Our proposal takes inspiration from two precedents. In Bangladesh, in the south-central districts of Gopalganj, Barisal and Pirojpur, farmers in flood-prone areas have for centuries built floating farms (locally known as “Dhap”) made of intertwined water hyacinth and aquatic grasses. These organic rafts serve as growing beds for leafy greens and vegetables during monsoon floods. The method transforms a challenge, prolonged inundation, into an opportunity for cyclical food production. In Europe, the Recycled Park in Rotterdam reinterprets this logic through contemporary design and circular economy principles. By collecting and recycling waste from the waterways, the project created floating gardens that reconnect urban residents with aquatic spaces.
The proposed floating farms for Manaus’ palafita communities are modular, fostering a circular and community-based economy. Through the collection of solid waste from the surrounding waterways (see image 7), plastic is recycled, processed with natural buoyant materials native to the Amazon region, and remodeled into floating farmbeds. During the flooding season, the farms float along the igarapés, producing greens and herbs for local consumption. During the dry season, they gently rest on mudflats beneath stilted houses, becoming dry-season gardens or composting beds.
Farms are easily connected through interlocking arms on the sides to prevent pieces from disconnecting in high flood. Elevated flat platforms can be used to walk along, store crops, and add additional surfaces where needed. Floating farms use custom recycled plastic drums to keep the farms buoyant in the water, with vertical rails on the edges with many flexible purposes: for connection, handrails, and elevated crops, etc. They are a fully enclosed system, with no direct contact with water
In the long term, these units could form networks of floating gardens along the igarapés, filtering polluted water, reducing heat, providing food, and supporting biodiversity. This proposal also supports the creation of a circular economy that designs out waste and pollution, circulates products and materials in a way that preserves value and regenerates nature.
The design proposal aims to drive the creation of small business ventures in the region to reprocess solid waste into recycled bedfarms.
6 Wastewater Treatment System
The wastewater system in image 6 is communal, laying the foundations of future connection to the city’s sewage infrastructure. Presently, only 30% of Manaus has sewerage connections, but a new initiative envisions dramatically expanding that coverage over time. The intermittent system we envision is built on cement stilts to adapt to seasonal floods and droughts, providing sewage treatment for four interconnected houses through a shared piped network. It is composed of a septic tank and anaerobic filter made of local materials such as brick fragments or crushed stone. The result is a treated effluent which infiltrates the ground through an infiltration tank, during dry seasons. During the flood season, the treated effluent is dispersed naturally through the surrounding waterways.
Critically, to enable such a system and build out a circular economy, we envision a local incubator space in Manaus which provides a platform for community members to collectively identify, design, and adapt low-cost technologies that address situated needs. For example, nimble and portable fecal sludge extractors, e.g. Vacutug, have been critical to safe sludge removal in low-income settlements in other parts of the world. Here, such machines can be leveraged and adapted for safe sludge removal in fluvial urban neighborhoods while also creating safe and hygienic employment opportunities and room for entrepreneurship.
7 Waste
Palafitas accumulate waste because of spatial inaccessibility, seasonal flooding which brings waste from upstream areas into the neighborhood, and social marginalization, which together create a cycle of environmental degradation and health risks.
As a solution, we envision a prefabricated, modular waste-barrier system, a Modular Litter Trap (image 7), that uses deployable netting and buoyant cages to track along the stilt posts, rising and falling with the tide. These netted enclosures channel the natural energy of water flow to capture and drain floating debris, isolating waste before it accumulates in residential backwaters. Once filled, the cages can be detached and emptied manually via the maromba platforms or by boat, minimizing decay and leaching into the river. We envision the municipality of Manaus employing residents of the palafitas as waste collectors, building on existing labor organizations of catadores in Manaus and across the Amazon region to foster transnational solidarity among fluvial communities.
Additionally, the maromba is expanded to 0.9 meters in width to improve accessibility and maintenance, allowing this mechanism to help keep palafita neighborhoods clearer of floating trash and manage the waste carried in by river currents from surrounding areas.