City infrastructure (e.g., reduced flooding, improved water quality)

The South Hennepin Marsh habitat restoration project, located below the Grosse Ile Toll Bridge causeway, within the Detroit River's Trenton Channel near Grosse Ile, Michigan, aims to restore and protect one of the region's most critical wetland habitats. This emergent marsh, historically vital for fish and wildlife, has suffered significant degradation due to river currents, boat traffic, and winter ice flows. The project, identified as a priority in the 2002 Habitat Protection and Remediation report for the Detroit River, encompasses the restoration of over 1,000 linear feet of protective shoals and 20 acres of productive wetlands, home to various native plant species such as rushes and submergent macrophytes.

The primary goal of the project is to stabilize and enhance the marsh's habitat, improving conditions for fish, waterfowl, reptiles, amphibians, and other wildlife. Restoration activities include the placement of approximately 10,000 cubic yards of rock and soil to rebuild eroded shoals, installation of erosion matting, and re-establishment of native vegetation. Additional habitat features, including habitat logs, mudpuppy structures, and stone spawning beds, will provide crucial breeding and feeding areas for species such as walleye, northern pike, and lake whitefish.

The project also incorporates soft engineering solutions, such as fallen branched trees and strategically placed stones, to support pollinators, birds, and reptiles. Feasibility studies and design plans were completed by Environmental Consulting and Technology, with funding from NOAA, and construction was carried out by E.C. Korneffel Company beginning in 2021. The project reached completion in November 2022, successfully restoring the shoals and protecting the marsh from further degradation. These efforts have significantly enhanced habitat availability, ensuring the sustainability of the South Hennepin Marsh as a critical ecological site within the Detroit River system.
(Ref.1-4)

The redesign of Reinprechtsdorfer Street in Vienna is a greening initiative aimed at climate adaptation by reducing local temperatures and increasing green space in a densely built urban area. Implemented within one year, the project included planting trees, adding green beds, and widening the pavement to create a more inviting environment. New seating areas, drinking stations, and water play installations were introduced, providing spaces for relaxation, cooling off during high temperatures, and fostering social interaction. Accessibility and traffic safety were enhanced by leveling the pavement with the street and adopting a one-way system for cars.
The project, realized in 2023, was part of Vienna's city-wide "Out of the Tarmac" initiative and was spearheaded by the district and city council. It originated from discussions and a participatory design process with citizens dating back to 2014. Previously, Reinprechtsdorfer Street served as a congested connection between Wienzeile and Gürtel. The plan seeks to transform it into a “climate-friendly shopping street.”
The redesign involves planting 32 new trees accompanied by flower beds, plus three standalone flower beds. Sidewalks were widened, and amenities included parking for 36 bicycles, nine benches, and seating for 46 individuals. Cooling features such as two water installations, three mist columns, and two drinking hydrants will enhance comfort.
Renovation began in spring 2023, focusing first on the 400-meter stretch between Schönbrunner Straße and Arbeitergasse. A structurally separate one-way cycle path will link Schönbrunner Straße to Bräuhausgasse, while the existing cycle lane against the one-way system remained unchanged. (Ref. 1, 2, 6)

The green belt regeneration project along the Byzantine Walls of Thessaloniki aims to revitalize the neglected green spaces surrounding these historic fortifications, which span 4 kilometers and are recognized as a UNESCO World Heritage site for their remarkable Byzantine architecture. The walls are located in Thessaloniki’s densely populated Upper Town, a factor that contributed to their environmental degradation. As such, the project focuses on restoring the degraded space surrounding the walls, improving the urban microclimate, and strengthening urban resilience while maintaining the area’s traditional character. By integrating heritage conservation with sustainable green infrastructure, the initiative seeks to provide both environmental and social benefits to the local community. Proposed by the Municipality of Thessaloniki and approved by the Greek government as part of a program that focuses on Central Macedonia, the project envisions a revitalized green zone along the walls, with vegetation and different types of trees being planted. However, some local families have expressed concerns, as the project involved the demolition of certain homes in the officially designated green belt area. (Refs. 1, 2, 3, 4, 14).

The Grand Parc des Aygalades project involves the creation of a 14-hectare metropolitan park (connecting Aygalades Park with Bougainville Park and François Billoux Park) that will connect the northern neighbourhoods of Marseille to the port located further south (Ref 1). This project is part of the green conversion of Marseille's northern districts, historically among the most disadvantaged areas in France (Ref 1). The Grand Parc des Aygalades project will enhance the city's greenery, reduce flood risks, create cool zones, restore and develop biodiversity, and significantly improve residents' quality of life and air quality (Ref 1, Ref 2). The environmental and social challenges include reconnecting the populations of these neighborhoods to green spaces, services, education, sports opportunities (Ref 2).
The park project includes redesigning urban infrastructure to improve rainwater absorption and reduce flood risks, addressing the issue of impermeable and artificialized soils that exacerbate flooding during heavy rainfall (Ref 1). It also involves renaturing a 17-kilometre-long stream currently buried under railway tracks, improving flood management and rainwater drainage (Ref 1, Ref 4). The project will also convert a heavily degraded former industrial site, requiring the rehabilitation of polluted soils (Ref 1). Additionally, creating green corridors aims to mitigate the heat island effect, particularly severe in these northern districts due to the high concentration of buildings and concrete surfaces, and the lack of green spaces. Public participation will be encouraged through information meetings, thematic workshops, and an online platform for submitting ideas and feedback (Ref 4).

The Oxygen Alley project, developed by the NGO Arboretum Detroit, is a green space located in the Poletown East neighborhood of Detroit. Spanning four formerly abandoned lots, the project, completed in 2023, serves as a significant environmental and community initiative aimed at improving local resilience and promoting environmental justice. Named in recognition of the closure of the Detroit waste incinerator—a major source of pollution for over 30 years—the project replaces a long-abused landscape with a thriving greenway that enhances both the ecological health and social well-being of the area.
Key features of Oxygen Alley include the planting of air-filtering trees and the creation of a shaded greenway lined with wildflowers, benches, and walking paths. This new green space not only provides a recreational area for residents but also functions as a natural air conditioner, stormwater sponge, and wildlife habitat. It addresses the neighborhood’s lack of tree cover, offering shade and cleaner air while helping mitigate the effects of climate change.
The project also underscores the neighborhood's longstanding struggle for environmental justice. The removal of 400 feet of asphalt and the remediation of a polluted landscape highlight the community’s efforts to reclaim and revitalize their environment. Oxygen Alley serves as both a functional green space and a monument to the residents’ victories over the waste industry, symbolizing their continued fight for clean air and livable spaces.
Supported by grants from the City of Detroit, Michigan Department of Natural Resources, and DTE Energy Foundation, among others, the project was brought to life through over 300 hours of volunteer labor. The creation of this greenway not only improves the neighborhood’s walkability but also offers a vision for a more sustainable and equitable future, serving as a model for urban revitalization projects across Detroit and beyond.
(Ref.1,2,3)

The regreening project is located in Seestadt Aspern, a newly developed urban area in Vienna's Donaustadt district. Two years after the completion of buildings, streets, and squares, the ground was reopened in 2022 to address the challenges posed by urban heat islands. Pavement was removed, and trees and shrubs were planted to provide shade, create insect habitats, and open seepage areas for rainwater. Additional features like benches, a water station, and water jets were installed to enhance the area's livability. These measures improve the overall quality of life, offering residents green spaces to relax and opportunities to cool down through water play.
The project spans three connecting squares in Seestadt: Wangari Maathai Square, Simone de Beauvoir Square, and Eva Maria Mazzucco Square. In 2022, Wangari-Maathai-Platz and Simone-de-Beauvoir-Platz underwent intensive regreening. By 2023, Eva-Maria-Mazzucco-Platz in the Seeparkquartier was similarly transformed with additional greenery and cooling features. Under the slogan "Out of the Asphalt," one of Europe's largest and most innovative urban development projects took a significant step toward improving quality of life.
In 2023, over 1,100 square meters of asphalt were removed and greened. This effort included the creation of 12 new green beds planted with grasses, perennials, and shrubs. The design also introduced two square-like recreation areas with existing seating elements surrounded by green beds, providing shaded, pleasant spaces for relaxation.
The Eva-Maria-Mazzucco square was designed by a local NGO specializing in citizen engagement in urban development, while the project's overall initiation and implementation were led by the City of Vienna, the Donaustadt district, and Wien 3420 Aspern Development AG. This collaborative effort demonstrates how regreening initiatives can mitigate heat islands, foster urban biodiversity, and create more attractive, livable spaces. (Ref. 1-3)

The city of Thessaloniki is tackling the energy crisis and climate change risks by prioritizing the installation of green roofs and green walls on school and municipal buildings as part of its resilience strategy, Thessaloniki 2030 (Ref 1, 2). One key project under this strategy has been implemented at EPAL Stavroupoli, one of the largest school complexes in the metropolitan area. The school, with a total built area of 11,918 sq.m and roof surfaces covering 6,042 sq.m, now includes a green roof covering 3,087 sq.m with 25,000 ground-cover plants, along with a vertical garden on three walls at the entrance, covering 100 sq.m and featuring 3,098 plants (ibid.).
The project is expected to yield multiple environmental benefits, such as reduced energy losses, improved thermal performance, enhanced sound insulation, better rainwater management, decreased runoff, and retention of harmful particles, all of which contribute to upgrading the area's green infrastructure (Ref 1). This initiative also strengthens the green fabric of western Thessaloniki and improves the local microclimate while addressing rainwater management issues (Ref 3, 4).

The Helmut Zilk Park, named after the late Mayor of Vienna, is located in the heart of the city, near the central train station. Surrounded by newly constructed residential and office buildings, the park serves as a vital green space, offering a variety of amenities. From playgrounds and sports fields to a community garden and cafés, it provides a space for social interaction and recreation. The park is characterized by large open meadows, which function as rainwater seepage areas, and features over 500 trees along its pathways., as well as community gardens. Flower groves enhance the park’s visual appeal while also providing habitats for local wildlife. The natural edges of the park create a diverse urban biotope that supports various plant and animal species. Grass and meadow communities have been carefully planned to enhance biodiversity and provide wet, humid habitats that help infiltrate rainwater from the surrounding paved areas. Already in its first year, the park has become home to insects, small animals, and even larger species like rabbits and snakes, contributing to its rich ecosystem.
The park was developed by the local municipality of Vienna on a site that was once part of the city's railway track system. It is the largest park the city has created in the past 40 years, designed to serve as a recreational area for both local residents and travelers using the nearby train station.
This project is part of a broader urban development initiative around the former Southern Railway station, led by Austria’s Federal Railways Company (ÖBB) and the City of Vienna. The plans included residential housing, office spaces, social infrastructure, and the creation of the Helmut Zilk Park.
Spanning approximately 70,000 square meters, the park stands as the largest public green space created in Vienna in four decades. The central area of the park features a large lawn, perfect for picnics, ball games, and recreational activities. (Ref. 1, 2, 3, 8)

The Dog River Watershed Restoration project aims to protect and enhance the chemical, biological, and cultural integrity of the Dog River Watershed in Mobile County, Alabama (Ref 1). Guided by the Dog River Watershed Management Plan (WMP), the project addresses key issues such as pollution, litter, stormwater management, and habitat degradation (Ref 2). Funded by the National Fish and Wildlife Foundation's Gulf Environmental Benefit Fund and completed in partnership with stakeholders, the project focuses on implementing targeted restoration activities to improve water quality, protect critical habitats, and increase public awareness and access to the watershed (Ref 2). The Dog River Watershed faces significant hazards, including pollution, sedimentation, erosion, and the impacts of urban development (Ref 3). These challenges are intensified by the watershed’s role as an urban estuary, where land use heavily influences water quality and habitat conditions (Ref 3). To mitigate these threats, the project incorporates pollution prevention measures, shoreline restoration efforts, and community engagement initiatives (Ref 4). By prioritizing scientifically supported actions and aligning with broader environmental goals, the project seeks to restore ecological balance and ensure the long-term health and resilience of the watershed and its connected ecosystems in Mobile Bay (Ref 4).
The Watershed Management Plan for the Dog River Watershed is a key component of the Mobile Bay Shore Habitat Conservation and Acquisition Initiative, which focuses on acquiring, restoring, and preserving habitats and wildlife species affected by the environmental disasters of the Deepwater Horizon oil spill that occurred in 2010 (Ref 6). The project spans three critical areas: 300 acres in the Dog River Watershed (as detailed in this project profile), 450 acres within the Three Mile Creek Watershed, and 40 acres in the Garrows Bend Watershed (not in focus here) (Ref 7).

The Horpaz-Ezareni Park is an initiative driven by civil society, requesting the municipality of Miroslava to construct a natural park adjacent to Lake Ezareni. The aim is to protect its green spaces and aquatic bird species while addressing waste management in the area. The petition also called for more green spaces in line with European standards and sought to tackle the challenges of rapid urbanization in peri-urban areas. It collected hundreds of signatures and targeted an area of 20 hectares.
In response, the municipality agreed to the petition and initially proposed creating a park covering 4 hectares in 2022. This first plan was released to the public for consultation. However, the project has since evolved to encompass the original 20 hectares, plus an additional 2 hectares, with an estimated project cost of 11,000,000 euros and a timeline of 3 years for implementation.
The park's design includes various facilities and amenities aimed at enhancing opportunities for recreation, exercise, and relaxation. Accessible paths for pedestrians and cyclists, as well as a parking lot, are also part of the plan. Additionally, two buildings are proposed for sanitary and administrative purposes, which would manage the projected installations of a lighting system, Wi-Fi, and surveillance cameras.
Environmentally, the project includes plans for managing the lake's banks to remove hydrophilic vegetation that could create an unhealthy environment, along with the construction of two bridges. The wilderness areas will be managed, and dendrological plants will be introduced to improve the ecosystem's quality. Overall, the project aims to increase and regenerate green spaces in the commune, enhancing the quality of life for residents and improving the area's aesthetic appeal. (1-8)