SUDs on Avenida de las Asociaciones de Vecinos
To reduce the risk of urban flooding, the city of Seville, through its metropolitan water company Emasesa, established several "sustainable urban drainage systems". One of the pilot locations is on the Avenida de las Ascociaciones de Vecinos, where a rain garden complemented by an infiltration zone was established. The main aim of the project is to reduce the risk of flooding, but the system can also improve the urban landscape by offering green space, preventing desertification and reducing pollutants carried by runoff [Ref. 1-4]. After implementation, the project was shown to be effective during heavy rain [Ref. 5]. The system can store up to 34 m2 of water and reduce flow rates to the sewage network by 69 % and the total runoff to sewage by 93 % [Ref. 3-5]. The project was initiated and led by Emamesa, while two different companies were employed to design and construct the system [Ref. 1, 2, 6, 7]. The total budget of the project, which also included some renovations of grey infrastructure along the street, was 165000 EUR [Ref. 1].
Urban wetland on industrial site
On the site of a former malthouse in Berlin, a company has developed a sustainable rainwater storage system to prevent flooding in the sealed environment, which had been vacant for several years. Once used for malt production, the site is now home to offices, studios, manufacturing businesses, and hosts sustainable events. The site's transformation includes natural gardens, tenant gardening beds, green roofs, and two outdoor water basins that retain rainwater, creating a blue space for recreation. (Ref. 1)
The two ponds are filled with filtered rainwater, and an underground tank stores additional water, allowing it to seep away gradually. Native plants surround the ponds, creating a habitat for local wildlife. Given that much of the surrounding area is sealed, the ponds help mitigate urban flooding by managing and storing rainwater, reducing the site's reliance on the urban sewage system. Additionally, as Berlin faces extreme heat in summer, the project offers a cooling effect and provides access to filtered water during droughts. (Ref. 1; Ref. 2)
The project is managed and financed by IGG Malzfabrik mbH, which oversees the entire site in Berlin's industrial area and rents out office spaces to various companies. This initiative is part of a broader sustainability strategy that addresses social, economic, and ecological factors, and it is featured in the company’s common good economy report (Gemeinwohl-Ökonomie Bericht). (Ref. 5)
The two ponds are filled with filtered rainwater, and an underground tank stores additional water, allowing it to seep away gradually. Native plants surround the ponds, creating a habitat for local wildlife. Given that much of the surrounding area is sealed, the ponds help mitigate urban flooding by managing and storing rainwater, reducing the site's reliance on the urban sewage system. Additionally, as Berlin faces extreme heat in summer, the project offers a cooling effect and provides access to filtered water during droughts. (Ref. 1; Ref. 2)
The project is managed and financed by IGG Malzfabrik mbH, which oversees the entire site in Berlin's industrial area and rents out office spaces to various companies. This initiative is part of a broader sustainability strategy that addresses social, economic, and ecological factors, and it is featured in the company’s common good economy report (Gemeinwohl-Ökonomie Bericht). (Ref. 5)
The New Headquarters of UN office in Nairobi
Established in 1996, the United Nations Office at Nairobi (UNON) is the UN's official headquarters in Africa, located just 9.7 km from the heart of Nairobi. In line with the UN's global sustainability goals, the office took significant steps to reduce its environmental footprint as it expanded. According to the United Nations Environment Programme (UNEP), buildings contribute to a third of global energy use and are major sources of greenhouse gas emissions. To address these issues, new buildings were designed to prioritize energy and water efficiency, with a focus on sustainability.
Completed in 2011, the new headquarters reflect the UN's broader commitment to reducing greenhouse gas emissions. The design includes 6,000 m² of solar panels, rainwater harvesting systems, energy-efficient lighting, and natural ventilation, making the complex energy-neutral and water-efficient. It generates as much solar energy as it consumes, supporting over 1,200 staff members. Additionally, the project carefully preserved indigenous trees and created micro-ecosystems within the interior gardens, further aligning with the UN’s environmental mission.
By embedding these green features, the UNON complex serves as a model for sustainable development in urban settings, echoing the UN’s efforts to combat climate change and promote ecological resilience globally. (Ref. 1, 2, 3, 4)
Completed in 2011, the new headquarters reflect the UN's broader commitment to reducing greenhouse gas emissions. The design includes 6,000 m² of solar panels, rainwater harvesting systems, energy-efficient lighting, and natural ventilation, making the complex energy-neutral and water-efficient. It generates as much solar energy as it consumes, supporting over 1,200 staff members. Additionally, the project carefully preserved indigenous trees and created micro-ecosystems within the interior gardens, further aligning with the UN’s environmental mission.
By embedding these green features, the UNON complex serves as a model for sustainable development in urban settings, echoing the UN’s efforts to combat climate change and promote ecological resilience globally. (Ref. 1, 2, 3, 4)
"Rain garden" along the October 28th street in Thessaloniki
The 28th of October Street (28ης Οκτωβρίου) was one of the most neglected streets on the eastern side of Thessaloniki, completely devoid of trees despite its central importance. Additionally, the street suffered from severe flooding during heavy rainfall. In 2011, the Municipality of Thessaloniki, in collaboration with Konstantinos Zervas, the Deputy Mayor for the Environment, Quality of Life, and Free Space, proposed a redevelopment project aimed at transforming the street through the planting of trees and the installation of flower beds that would function as rain gardens (Refs 3, 5). This initiative was part of the "Integrated Green Cities" action, which falls under the European territorial cooperation program Greece-Bulgaria 2007-2013 (Refs 1, 2, 3, 6).
To achieve the dual goals of sustainable rainwater management and urban beautification, decorative trees were planted in specially constructed bioretention tree stands. These stands, along with the flower beds, were designed to collect rainwater, which would then be used to irrigate the trees along the road and the plants forming the rain gardens. Rainwater was gathered from the road surface, pavements, and the gutters of apartment buildings through these bioretention systems (Refs 1, 2). This sustainable water management solution significantly reduced rainwater runoff, improved water quality, and enhanced the area’s aesthetic appeal (Refs 2, 6, 7).
To achieve the dual goals of sustainable rainwater management and urban beautification, decorative trees were planted in specially constructed bioretention tree stands. These stands, along with the flower beds, were designed to collect rainwater, which would then be used to irrigate the trees along the road and the plants forming the rain gardens. Rainwater was gathered from the road surface, pavements, and the gutters of apartment buildings through these bioretention systems (Refs 1, 2). This sustainable water management solution significantly reduced rainwater runoff, improved water quality, and enhanced the area’s aesthetic appeal (Refs 2, 6, 7).
Plant-based filter water treatment
In 2024, Ozanam (a housing private company) and the French Development Agency (AFD) formalized a partnership to modernize an ecological wastewater treatment plant in Saint-Joseph, a neighborhood in Fort de France. The project focuses on replacing an outdated 30-year-old installation that no longer meets current standards with a plant-based water filtration system based on the ‘Rhizosph’air’ patent. This innovative treatment process utilizes "filter gardens," which combine mechanical systems, a gravity network, and a phytoremediation approach. The system employs filters made of gravel and the roots of local plants, specifically Strelitzia reginae and Cyperus alternifolius, to naturally and effectively filter wastewater without odor (Refs 2, 3, 4).
The nature-based system purifies wastewater over an area of 2,000 square meters, with a capacity equivalent to serving 900 residents. This approach offers several advantages, including reduced maintenance costs due to its simplicity, decreased energy consumption compared to traditional treatment methods, and improved water quality released back into the environment (Ref 2). Beyond its technical efficiency, the filter gardens enhance biodiversity (Ref 2) by improving the quality of water discharged into the environment and providing habitats for various species. The solution also integrates seamlessly into the landscape, showcasing vibrant flowers native to the area (Ref 1).
Additionally, the project implementers plan to construct a walking path, provide recreational equipment, and install benches to encourage residents to utilize the area as a public green space (Refs 2, 5).
The nature-based system purifies wastewater over an area of 2,000 square meters, with a capacity equivalent to serving 900 residents. This approach offers several advantages, including reduced maintenance costs due to its simplicity, decreased energy consumption compared to traditional treatment methods, and improved water quality released back into the environment (Ref 2). Beyond its technical efficiency, the filter gardens enhance biodiversity (Ref 2) by improving the quality of water discharged into the environment and providing habitats for various species. The solution also integrates seamlessly into the landscape, showcasing vibrant flowers native to the area (Ref 1).
Additionally, the project implementers plan to construct a walking path, provide recreational equipment, and install benches to encourage residents to utilize the area as a public green space (Refs 2, 5).
Lake Dianchi Freshwater Biodiversity Restoration Project
Situated in the southern suburbs of Kunming City, Dianchi is one of the largest freshwater lakes in Yunnan and the sixth largest in China (Refs 1, 2). However, due to rapid industrial development, agricultural activities around the lake, land reclamation, and population growth, Dianchi Lake became severely polluted, ranking among the most contaminated lakes in China. This pollution threatened biodiversity and degraded natural habitats (Refs 1, 2, 3). The introduction of exotic species further disrupted the lake’s ecological balance (Ref 1).
In response, the Kunming Institute of Zoology (KIZ), with funding from the Chinese Government, World Bank and the Global Environment Facility (GEF) launched the Lake Dianchi Freshwater Biodiversity Restoration Project. This initiative aimed to restore natural habitats, improve water quality through biological means, and foster community engagement and institutional capacity, creating a sustainable framework for the long-term conservation of Dianchi's unique freshwater biodiversity (Refs 1, 4).
The project was implemented across four key components: Wetland Management and Restoration, Surveys and Monitoring of Species Conservation, Capacity Building and Training, and Public Awareness (ibid.). The project was rated 'Satisfactory' in terms of outcomes, sustainability, and execution under a comprehensive evaluation framework that employed multiple indicators (Refs 4, 5).
In response, the Kunming Institute of Zoology (KIZ), with funding from the Chinese Government, World Bank and the Global Environment Facility (GEF) launched the Lake Dianchi Freshwater Biodiversity Restoration Project. This initiative aimed to restore natural habitats, improve water quality through biological means, and foster community engagement and institutional capacity, creating a sustainable framework for the long-term conservation of Dianchi's unique freshwater biodiversity (Refs 1, 4).
The project was implemented across four key components: Wetland Management and Restoration, Surveys and Monitoring of Species Conservation, Capacity Building and Training, and Public Awareness (ibid.). The project was rated 'Satisfactory' in terms of outcomes, sustainability, and execution under a comprehensive evaluation framework that employed multiple indicators (Refs 4, 5).
Chaowan Nursery Garden Base Project
The Chaowan Nursery Garden Base Project (潮玩苗圃基地), located along the Dianchi Greenway in Kunming, was established by the Kunming Gardens Virescence Bureau (昆明市园林绿化局) in 2022 as part of the city's efforts to transform into a "city of parks" (Ref 2, 3). Covering 639 mu (42.6 hectares), the Chaowan Nursery Garden has introduced over 1.4 million plants, including trees, flowers, and grasses, greatly expanding the city's green spaces (Ref 3). It serves as a key resource for the Kunming Greening Service Center (昆明市绿化服务中心), providing seedlings for major greening projects along roads like Guangfu Road, Airport Road, Beijing Road, and the Second Ring Elevated Road (Ref 4).
Innovatively designed, the nursery also functions as a park, offering an "immersive" experience with various themed areas such as rainwater gardens, rural gardens, Chinese gardens, and scenic balconies. These spaces allow visitors to stroll through and enjoy the beauty of various flowers and natural surroundings (Ref 4). The project also collaborates with local universities on seedling research, capacity building, and resource sharing, further enhancing its multifaceted role (Ref 3).
Since opening to the public in 2023, the Chaowan Nursery Garden has become a popular destination for families, young people, and children, offering both recreational and educational experiences (Ref 5, 6, 7, 8).
Innovatively designed, the nursery also functions as a park, offering an "immersive" experience with various themed areas such as rainwater gardens, rural gardens, Chinese gardens, and scenic balconies. These spaces allow visitors to stroll through and enjoy the beauty of various flowers and natural surroundings (Ref 4). The project also collaborates with local universities on seedling research, capacity building, and resource sharing, further enhancing its multifaceted role (Ref 3).
Since opening to the public in 2023, the Chaowan Nursery Garden has become a popular destination for families, young people, and children, offering both recreational and educational experiences (Ref 5, 6, 7, 8).
Belt Line Center PACE-funded Green Roof
The Belt Line Center building, located in Detroit, Michigan, property of Letts Industries, features a green-blue roof, along with a rain garden, showcasing the benefits of green infrastructure in historic properties. The idea for this retrofit emerged in 2015 after a major renovation, when Chip Letts, CEO of Letts Industries, recognized the potential of green infrastructure for long-term energy efficiency and storm-water management.
The initiative gained momentum in 2018, following the Detroit Water and Sewerage Department's (DWSD) introduction of new drainage fees, which charged $750 per acre of impermeable surfaces. The DWSD also offered up to 80% discounts for properties implementing green solutions, further incentivizing the project.
The project officially began in 2020 after securing PACE funding (Property Assessed Clean Energy funding, a financing mechanism that enables property owners to fund energy efficiency, renewable energy, and water conservation projects) from CounterpointeSRE (financial institution), marking the first use of commercial PACE financing for a green roof in Michigan. The green roof, covering 17,250 square feet, includes 300 square feet of pedestal pavers and a 2,500 square foot blue roof. These features enhance stormwater management, energy efficiency, and roof longevity; the center also incorporates two beehives to support local biodiversity.
These systems work in tandem with the ground-level rain garden to capture and infiltrate stormwater runoff, significantly reducing the impact on Detroit’s stormwater system. The project aligns with the city’s broader sustainability goals, including the Beltline Greenway initiative, which will pass directly behind the property, integrating the building into Detroit’s expanding network of green spaces and bike paths.
The Belt Line Center serves as a model for revitalizing historic buildings through innovative financing and sustainable design, enhancing Detroit’s environmental resilience. (Ref.1-5)
The initiative gained momentum in 2018, following the Detroit Water and Sewerage Department's (DWSD) introduction of new drainage fees, which charged $750 per acre of impermeable surfaces. The DWSD also offered up to 80% discounts for properties implementing green solutions, further incentivizing the project.
The project officially began in 2020 after securing PACE funding (Property Assessed Clean Energy funding, a financing mechanism that enables property owners to fund energy efficiency, renewable energy, and water conservation projects) from CounterpointeSRE (financial institution), marking the first use of commercial PACE financing for a green roof in Michigan. The green roof, covering 17,250 square feet, includes 300 square feet of pedestal pavers and a 2,500 square foot blue roof. These features enhance stormwater management, energy efficiency, and roof longevity; the center also incorporates two beehives to support local biodiversity.
These systems work in tandem with the ground-level rain garden to capture and infiltrate stormwater runoff, significantly reducing the impact on Detroit’s stormwater system. The project aligns with the city’s broader sustainability goals, including the Beltline Greenway initiative, which will pass directly behind the property, integrating the building into Detroit’s expanding network of green spaces and bike paths.
The Belt Line Center serves as a model for revitalizing historic buildings through innovative financing and sustainable design, enhancing Detroit’s environmental resilience. (Ref.1-5)
Eastside City Park in Birmingham
As an industrial city under climate change, Birmingham has been confronted with multiple environmental risks such as air pollution, fluctuating precipitation and flooding (Ref 3). The Big City Plan is a 20-year city center regeneration plan to support Birmingham’s sustainable transformation, where the delivery of the Eastside City Park was prioritized (Ref 1, 2). Completed and opened to public in 2013, this first new park in Birmingham for 130 years is a linear site which connects the city center along the frontage of Millennium Point eastwards towards the Digbeth canal. (Ref 1, 4, 5). Providing 2.73 ha of urban green spaces, the multi-award winning development features more than 300 trees, a 110 meter canal water feature and a public square with 21 jet fountains, and offers “a moment of green in a journey through the city” (Ref 1, 6).
