Rain Garden in the Lagoa do Nado Park

Maintenance and management of urban nature existing green areas, Management and improved protection of rivers and other blue areas

Two rain gardens have been implemented in the Lagoa do Nado Park as a nature-based solution that "contribute[s] to the capture of rainwater, help[s] prevent flooding...and help[s] solve climate problems" in the urban area (Ref. 7). In addition to creating storage spaces that "facilitate the infiltration of water into the soil and the recharge of the water table", the rain garden was also implemented to harness the biological activity of plants and microorganisms to remove pollutants from these waters" (Ref. 7). The rain garden was implemented as a demonstration project, to show how nature-based solutions can be used as a method by which to "integrate biodiversity and sustainability into urban planning, territorial management and urban infrastructure projects, in addition to working as a complement to drainage services in the rainy season" (Ref. 7). The project was approached as "another important investment in the Pampulha Region, which aims to present alternatives for the infiltration of rainwater, which, driven by the waterproofing of the soil, causes flooding in several areas of the city" (Ref. 6). The rain garden is intended to "help...the drainage system to work within its capacity even during peak rainfall", alleviating the occurrence and impacts of urban flooding (Ref. 2). During the inauguration of the rain garden, this goal was further underlined by Environment Secretary, Mário Werneck, stating, "This is a significant example of the search for efficient and innovative alternatives for the quality of life of our community. Rains are a problem that plagues the entire Metropolitan Region, especially at this time of year. Living with this scenario, it is necessary to think of sustainable solutions that help solve this problem, as is the case with the implementation of rain gardens”, and the superintendent of Sudecap, Henrique de Castilho Marques de Sousa, stating that "as well as the great infrastructure works that are being developed, this strategy is one of the ideas for the future that help the municipality to solve the climatic problems in urban [spaces]" (Ref. 2).

Considered a “model of smart infrastructure”, implementation of the rain garden aimed "to present alternatives for the infiltration of rainwater, which, driven by the waterproofing of the soil, causes flooding in several areas of the city" (Ref. 4). Two rain gardens were constructed over an area of 150 square meters each (Ref. 7), reportedly comprising a total volume of 360 cubic meters (Ref. 4). Due to its being "deeper", the rain garden has "space for water to be reserved for a certain time, helping to reduce flooding and flooding. The idea is that rainwater runs down the sidewalks, enters the garden and has space to remain" (Ref. 7). Implementation of the rain garden therefore included creation of "structures that contribute to the capture of rain, creating storage spaces that facilitate its infiltration into the soil and help in the recharge of the water table" (Ref. 2, Ref. 3), with the idea that these "structures receive the water runoff and accumulate excess, forming puddles that gradually infiltrate the soil, helping the drainage system to work within its capacity even during peak rainfall" (Ref. 2, Ref. 3). Having been created, the rain garden was planted with "tree and shrub species to promote biological diversity and agroecological soil management" (Ref. 1). Also referred to as a Bioretention System, planting of the rain garden with flora was undertaken in order to "use the biological activity of plants and microorganisms to remove pollutants from rainwater, contributing to the infiltration and retention of rainwater" (Ref. 2, Ref. 3). Plants introduced into the rain garden were "chosen based on technical criteria: the idea is to work with species that absorb and treat water, such as taioba" (Ref. 7). By undertaking the above implementation activities, "part of the water infiltrated in the vegetation returns to the water table, and the surplus not absorbed by the soil is sent to the system's drainage network, such as storm drains and storm sewers" (Ref. 7).

• Citizens or community groups