Alexandria Water Company Green Roof Campaign
The Alexandria Governorate is especially susceptible to the impacts of climate change, a vulnerability exacerbated by its dense coastal communities and rapidly growing population (2). Both demographic shifts and urban development intensify how climate phenomena affect the people and infrastructure of Alexandria (1). Buildings, roads, and other concrete structures absorb and release solar heat, significantly contributing to the urban heat island effect, which is causing temperatures in the city to rise faster than in less developed areas (1). Despite Alexandria’s growing need for cooling green spaces, they currently make up only 0.25 percent of the total area within the Governorate, highlighting an urgent need for environmental interventions (3-6).
In response, Ahmed Gaber, chairman of the Alexandria Water Company, initiated a public awareness campaign in 2023 focused on the numerous benefits of planting green roofs (3-6). Green roofs serve multiple purposes: they extend the longevity of buildings, lower energy consumption, improve air quality, increase biodiversity, manage rainwater runoff, and mitigate the urban heat island effect (3). Furthermore, Gaber has emphasized the visual appeal of eco-friendly roofs, noting that green roofs offer an aesthetically pleasing option that enhances the urban landscape while serving critical environmental functions (4).
This initiative by the Alexandria Water Company marks a pioneering step among governmental organizations in the region, as they lead efforts to address climate and environmental challenges actively. The company has begun planting green roofs across its facilities, including the new Al-Mashishya water station, where green spaces atop buildings are set to bring lasting environmental benefits to Alexandria. Through these efforts, the Alexandria Water Company is working to set an example for public and private sectors alike (3-6).
In response, Ahmed Gaber, chairman of the Alexandria Water Company, initiated a public awareness campaign in 2023 focused on the numerous benefits of planting green roofs (3-6). Green roofs serve multiple purposes: they extend the longevity of buildings, lower energy consumption, improve air quality, increase biodiversity, manage rainwater runoff, and mitigate the urban heat island effect (3). Furthermore, Gaber has emphasized the visual appeal of eco-friendly roofs, noting that green roofs offer an aesthetically pleasing option that enhances the urban landscape while serving critical environmental functions (4).
This initiative by the Alexandria Water Company marks a pioneering step among governmental organizations in the region, as they lead efforts to address climate and environmental challenges actively. The company has begun planting green roofs across its facilities, including the new Al-Mashishya water station, where green spaces atop buildings are set to bring lasting environmental benefits to Alexandria. Through these efforts, the Alexandria Water Company is working to set an example for public and private sectors alike (3-6).
Storm Water Management Program Plan
The City of Mobile has developed and implemented a Storm Water Management Program (SWMP) as required by the regulations of the Environmental Protection Agency (Ref 1). Flooding is a significant issue in Mobile, occurring frequently throughout the town (Ref 3). The SWMP aims to protect water quality and prevent harmful pollutants in stormwater runoff from entering the Municipal Separate Storm Sewer System (MS4) area (Ref 1). Stormwater runoff refers to rainfall that does not seep into the ground but instead flows over yards, streets, parking lots, and buildings, eventually entering the storm sewer system, which directs it into creeks, rivers, bays, and the Gulf of Mexico (Ref 1). Stormwater can collect pollutants such as trash, debris, sediment, heavy metals, oils, and hazardous household materials. Additionally, development increases impervious surfaces, leading to more stormwater runoff (Ref 2).
Nairobi River Basin Programme (NRBP)
Rapid urbanization and a population density of 6,247 people per km² have placed significant stress on Nairobi's natural resources (Ref 1). The 40-km long Nairobi River Basin, originating from the Ondiri Swamp, serves as a vital water source for the city (Ref 1, 2). However, it has suffered severe pollution from untreated sewage, solid waste, industrial contaminants, plastics, and agricultural runoff (Ref 1, 3). This degradation has had a serious impact on the ecosystem, local residents, and biodiversity (Ref 3).
To address these issues, the Nairobi River Basin Programme (NRBP), sponsored by UNEP, was launched in 1999 (Ref 4). Since then, government and non-state actors have worked together on solid waste management, riparian restoration, and wastewater control (Ref 1). The program was implemented in two phases: Phase I (2003–2006) and Phase II (2006–2009), involving stakeholders from the government, private sector, and civil society (Ref 1, 4, 5). Despite these efforts, a study from 2017 found significant tree removal along the river, and between 1988 and 2014, encroachment into the 30-meter riparian buffer zone dramatically increased, particularly between 2010 and 2014, further degrading the river’s health (Ref 1).
To address these issues, the Nairobi River Basin Programme (NRBP), sponsored by UNEP, was launched in 1999 (Ref 4). Since then, government and non-state actors have worked together on solid waste management, riparian restoration, and wastewater control (Ref 1). The program was implemented in two phases: Phase I (2003–2006) and Phase II (2006–2009), involving stakeholders from the government, private sector, and civil society (Ref 1, 4, 5). Despite these efforts, a study from 2017 found significant tree removal along the river, and between 1988 and 2014, encroachment into the 30-meter riparian buffer zone dramatically increased, particularly between 2010 and 2014, further degrading the river’s health (Ref 1).
Sustainable Urban Drainage System in Potsdamer Platz
In an architecturally important area of Berlin, situated between the Landwehr Canal, the Kulturforum (the Berliner Philharmonie and the Berlin State Library) and the new construction on Potsdamer Platz, a combination of green and grey infrastructure has been realised to minimise the burden on Berlin’s existing water infrastructure.
Green and non-green roofs harvest annual rain, which flows through the site’s buildings and is used for toilet flushing, irrigation, and fire systems. The roofs retain and then release water to the large on-site buffer pond, which has five underground storage tanks. Next to the roofs, a series of urban ponds and connecting canals have been implemented, with a combined area of approximately 1.2 hectares. They are filled with rainwater, creating an oasis for urban life. Vegetated biotopes are integrated into the overland landscape and serve to filter and circulate the water that runs along streets and walkways. The lake’s water quality is excellent, forming a natural habitat for animals and cooling the surroundings, while fresh water usage in the buildings has been reduced. (Ref. 1; Ref. 2; Ref. 3; Ref. 6)
The project was implemented in the 1990s as part of the development of Potsdamer Platz in the wake of the reunification of Germany. Several architects collaborated on the implementation that was completely privately funded. Beyond its ecological and technical features, the site is a blue natural site in the heavily built city centre of Berlin and allows people to linger and enjoy natural features. The drainage system won several sustainability prices and is considered a successful integration of nature and technology-based mechanisms to foster climate change adaptation. As the rainwater system stores rainwater in underground tanks and ponds, the urban sewage system is relieved during heavy rain, and water can evaporate. Therefore, the small water circle is closed, and the microclimate is cooled. (Ref. 2; Ref. 6)
Green and non-green roofs harvest annual rain, which flows through the site’s buildings and is used for toilet flushing, irrigation, and fire systems. The roofs retain and then release water to the large on-site buffer pond, which has five underground storage tanks. Next to the roofs, a series of urban ponds and connecting canals have been implemented, with a combined area of approximately 1.2 hectares. They are filled with rainwater, creating an oasis for urban life. Vegetated biotopes are integrated into the overland landscape and serve to filter and circulate the water that runs along streets and walkways. The lake’s water quality is excellent, forming a natural habitat for animals and cooling the surroundings, while fresh water usage in the buildings has been reduced. (Ref. 1; Ref. 2; Ref. 3; Ref. 6)
The project was implemented in the 1990s as part of the development of Potsdamer Platz in the wake of the reunification of Germany. Several architects collaborated on the implementation that was completely privately funded. Beyond its ecological and technical features, the site is a blue natural site in the heavily built city centre of Berlin and allows people to linger and enjoy natural features. The drainage system won several sustainability prices and is considered a successful integration of nature and technology-based mechanisms to foster climate change adaptation. As the rainwater system stores rainwater in underground tanks and ponds, the urban sewage system is relieved during heavy rain, and water can evaporate. Therefore, the small water circle is closed, and the microclimate is cooled. (Ref. 2; Ref. 6)
Real Dos Living Walls and Green Roofs
Located in the Lima district of San Isidro - the heart of commercial activity in Peru - the Real Dos Tower is a prime office building in the Centro Empresarial Real de San Isidro. It was inaugurated in 2018, and it is distributed over 23 levels (14 floors and 9 basements) and enjoys a landscaped green roof (1162 m2) at the crown of the building and numerous outdoor vertical gardens at full height (2365 m2) on the three main fronts (1, 4). This project was a finalist in the 2018 Mipim Awards, considered the ‘Oscars’ of world architecture, and stood out for its architecture and design, due to its attributes of innovation and sustainability (2).
This building has managed to create harmony between design and efficient use of resources. It is characterised by a glass façade with colourful movable shutters and symbolic Peruvian designs (2, 3, 6). It has green walls on the three main fronts, four daylight fronts and a roof garden (2). The architect, Jean Nouvel, worked together with ARVE Peru on the overall landscape plans for the Real Dos tower (1, 3).
This is part of the façade remodelling project of the Camino Real Towers in the Real Business Centre, led by the real estate company Grupo Centenario (1, 2, 3, 4, 5, 6). This overarching Project has sought to develop 4,475 m2 of vertical gardens and roof gardens, which have a technified irrigation system to generate efficiencies in water use, meeting the plants' water requirements in the different seasons of the year. Their implementation helps to filter CO2 and renew the O2 in the office complex.
The ARVE group describes these actions as conducive to creating thermal barriers and sound insulation, a better environment for rest, work and entertainment and increasing property value (7)
This building has managed to create harmony between design and efficient use of resources. It is characterised by a glass façade with colourful movable shutters and symbolic Peruvian designs (2, 3, 6). It has green walls on the three main fronts, four daylight fronts and a roof garden (2). The architect, Jean Nouvel, worked together with ARVE Peru on the overall landscape plans for the Real Dos tower (1, 3).
This is part of the façade remodelling project of the Camino Real Towers in the Real Business Centre, led by the real estate company Grupo Centenario (1, 2, 3, 4, 5, 6). This overarching Project has sought to develop 4,475 m2 of vertical gardens and roof gardens, which have a technified irrigation system to generate efficiencies in water use, meeting the plants' water requirements in the different seasons of the year. Their implementation helps to filter CO2 and renew the O2 in the office complex.
The ARVE group describes these actions as conducive to creating thermal barriers and sound insulation, a better environment for rest, work and entertainment and increasing property value (7)
The Airfield Community Garden
Airfield Estate, based in Dundrum, South County Dublin, is a dedicated sustainable food hub and Dublin’s only working urban farm and gardens. The 38-acre site, originally owned by the Overend family, attracts over 120,000 visitors for a fun day out including families, garden enthusiasts, schools, weddings and businesses.
The community garden at Airfield Estate is based on a partnership between the Estate and Toast corporation, a digital technology platform built for restaurants with an office in Dublin. The community garden was created to produce sustainable fruit and vegetables while also offering opportunities for people to learn about environmentally-friendly food production, empowering them to make more informed food choices. The Toast.org Community Garden at Airfield Estate will be a resource centre for education on nutrition, food sovereignty, seed saving, biodiversity, conservation, and resource management, supporting Toast.org’s mission to enrich the food experience for all. The community garden will also support Airfield Estate’s ambition to be Dublin’s sustainable food hub and help bring Dublin on its journey to be known as a world-leading sustainable food city (2, 3). The grounds will be accessible to everyone, from the local community and vulnerable groups to corporate employees, and the space will host horticulture talks and workshops on various topics. The partnership between Toast.org and Airfield Estate began in 2021 when some of Toast’s Dublin-based employees volunteered with the charity. The launch of the community garden is one of several ways Toast.org will support Airfield Estate throughout 2023. (2)
The community garden at Airfield Estate is based on a partnership between the Estate and Toast corporation, a digital technology platform built for restaurants with an office in Dublin. The community garden was created to produce sustainable fruit and vegetables while also offering opportunities for people to learn about environmentally-friendly food production, empowering them to make more informed food choices. The Toast.org Community Garden at Airfield Estate will be a resource centre for education on nutrition, food sovereignty, seed saving, biodiversity, conservation, and resource management, supporting Toast.org’s mission to enrich the food experience for all. The community garden will also support Airfield Estate’s ambition to be Dublin’s sustainable food hub and help bring Dublin on its journey to be known as a world-leading sustainable food city (2, 3). The grounds will be accessible to everyone, from the local community and vulnerable groups to corporate employees, and the space will host horticulture talks and workshops on various topics. The partnership between Toast.org and Airfield Estate began in 2021 when some of Toast’s Dublin-based employees volunteered with the charity. The launch of the community garden is one of several ways Toast.org will support Airfield Estate throughout 2023. (2)
Thessaloniki's New waterfront
Thessaloniki, Greece's second-largest urban center, is a key hub for economic growth and outward trade in the Balkans. The city hosts the country’s second-largest export port, which plays a crucial role in connecting European trade routes with Asia and China. However, until 2014, Thessaloniki's waterfront was poorly maintained, largely inaccessible, and unattractive. Moreover, major flooding events, connected to extreme weather events, exposed significant deficiencies in the city's flood mitigation infrastructure, leading to damage to housing and critical services. (5, 10, 11)
To address these issues, the Municipality of Thessaloniki launched an International Architectural Competition for the redevelopment of the New Waterfront. From 2006 to 2014, Thessaloniki's waterfront underwent a significant regeneration aimed at benefiting the city's population of 1.1 million and stimulating the local economy. The revitalized waterfront now stretches 3 kilometers between land and sea, featuring 58,000 acres of green space an playgrounds.. In total, 2,353 new trees and 118,432 plants were added across an area of 238,800 m² (Refs 1, 3, 4).
The project also introduced walking routes, sports and recreational facilities, seating areas, and scenic viewing points. The waterfront now has a bicycle path along the entire walkway, and an arbour of 660 umbrella pine trees, serving as shade from the midday sun. Completed in 2014, the New Waterfront has already become a vibrant urban green space, enjoyed by both Thessaloniki's citizens and visitors alike (Ref 4).
To address these issues, the Municipality of Thessaloniki launched an International Architectural Competition for the redevelopment of the New Waterfront. From 2006 to 2014, Thessaloniki's waterfront underwent a significant regeneration aimed at benefiting the city's population of 1.1 million and stimulating the local economy. The revitalized waterfront now stretches 3 kilometers between land and sea, featuring 58,000 acres of green space an playgrounds.. In total, 2,353 new trees and 118,432 plants were added across an area of 238,800 m² (Refs 1, 3, 4).
The project also introduced walking routes, sports and recreational facilities, seating areas, and scenic viewing points. The waterfront now has a bicycle path along the entire walkway, and an arbour of 660 umbrella pine trees, serving as shade from the midday sun. Completed in 2014, the New Waterfront has already become a vibrant urban green space, enjoyed by both Thessaloniki's citizens and visitors alike (Ref 4).
Choquehuanca Square
Lima is the capital of the region with the lowest coverage of green spaces. According to the World Health Organisation (WHO), a city should have at least 9m2 of green space per inhabitant. Lima is just over 3m2 square metres, which means a deficit of almost 60 million square metres. In this context, actions from the public and private sectors are essential to add this type of space to the city. In response to this need, Grupo Centenario carried out a green project on one of its plots of land in San Isidro, where real estate projects will be developed (1, 2, 3, 4).
A square was built with a green area with wild and low-consumption species, knocking down the walls that surrounded the land for years, turning it into a place for everyone to see and use (1, 2, 3, 4). The Choquehuanca Square was built to contribute to the community and make it a better place to live. It is located on a plot of land that was previously enclosed by walls, converting it into an area of 3,945 m2 with a green space that occupies 70% of the square (1, 2, 3). This is a temporary project, as the green space was opened while projects are being developed on this land (1, 2, 3).
A square was built with a green area with wild and low-consumption species, knocking down the walls that surrounded the land for years, turning it into a place for everyone to see and use (1, 2, 3, 4). The Choquehuanca Square was built to contribute to the community and make it a better place to live. It is located on a plot of land that was previously enclosed by walls, converting it into an area of 3,945 m2 with a green space that occupies 70% of the square (1, 2, 3). This is a temporary project, as the green space was opened while projects are being developed on this land (1, 2, 3).
"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).
Tirana Vertical Forest
The Tirana Vertical Forest is part of the city's 2030 Master Plan and aims to enhance urban biodiversity and create green spaces through innovative urban design (Ref. 1,2). The project was developed by Stefano Boeri Architetti, the same studio that has designed similar, well-known structures in cities like Milan, Utrecht and Nanjing (Ref. 6). The completion of the 21-floor building is expected in late 2024 and will feature 105 apartments and a commercial ground floor as well as 145 trees and over 3,200 shrubs and bushes which are integrated into the balconies and façade of the project (Ref. 1,2,3). Various Mediterranean plants have been incorporated, including colourful, scented and aromatic types, which harmonize with the local ecosystem. To maximise the space available for green features, a dynamic structure with alternating balconies and full-height windows has been built (Ref. 1,2). Ultimately, the project anticipates improving air quality, reducing noise, and providing insulation. The greenery is expected to capture fine particulate matter and up to 8 tones of Co2 per year while also creating a healthier microclimate for those inside the building (Ref. 1,6).
