In Belém, Brazil, the municipal government has begun the installation of rain gardens across different neighborhoods as a proactive measure to address flooding issues. This initiative, spearheaded by the Municipal Secretary of the Environment (Semma), is part of a broader strategy known as nature-based solutions (Soluções Baseadas na Natureza), which emphasizes sustainable urban planning. Rain gardens are essentially designed to absorb and retain rainwater, transforming urban spaces into sponge-like environments that manage water runoff more effectively.

The concept of these rain gardens is based on the idea of a 'sponge city,' where urban areas are transformed to better absorb rainwater instead of allowing it to quickly flow into drainage systems. These gardens are typically installed in areas that were previously impermeable, such as sidewalks and roadways, where rainwater can be directed. The design enhances the infiltration of rainwater into the soil, effectively reducing the volume of water that rushes through streets, a primary cause of flooding in the city, while also helping to filter dirt and pollutants before the water reaches urban drainage channels.

The project lists specific locations for the implementation of these rain gardens, indicating a structured approach to flood management in Belém. By integrating green infrastructure like rain gardens, the city aims to improve urban resilience against heavy rains and reduce the impacts of flooding, which have become increasingly common. This initiative not only addresses immediate environmental concerns but also promotes biodiversity and enhances the quality of urban spaces for the residents of Belém.