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

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)

Thessaloniki has a dense urban structure with limited open and green spaces. As a coastal city severely impacted by climate change, it faces multiple interconnected challenges, including extreme weather events, flooding, and peri-urban forest fires. These issues are further compounded by the city's aging infrastructure and deteriorating buildings, increasing its vulnerability (Ref 1).
Kipos 3, a community garden, is part of the "Green Neighborhoods" project proposed in the Thessaloniki 2030 municipal resilience strategy (ibid.). Established in 2015 on a 600-square-meter plot donated by the municipality, the garden is now managed by 30 local families under the continued stewardship of the Municipality (Ref 2, 3). The garden's creation was supported by a team of architects, landscape architects, and agriculturists, and features a variety of herbs and edible plants grown using permaculture methods (Ref 3).
The garden hosts a greenhouse along a range of environmental, recreational, and educational activities, providing an opportunity to foster a more cohesive, inclusive, and resilient community. It also serves as a space for synergies and discussions about the future of the city (Ref 3, 4). Recognized as a good practice, the intervention has been showcased in national, European, and international networks (Ref 2, 4).

Parque Central Hermanos Escobar had been neglected for years, but in 2022, it was fully reopened following a public investment aimed at redesigning some of its features. The renovations provided better amenities, new and improved recreational opportunities, and enhanced the city's resilience to flooding and water stress. Although the park already had a dedicated blue space, the renovations increased permeable surfaces (e.g., parking lots) and boosted its water retention capacity with cisterns, stormwater basins, and an artificial lake designed to function "like a natural one" (Ref 1).

The artificial lake was one of the most anticipated additions with a depth of one meter and being used for recreational purposes. It is supplied with water from the existing treatment plant in the park’s western section, which complies with the National Water Commission (Conagua) standards. The lake features recreational facilities, such as boats and a pier, and serves as a habitat for local wildlife, including ducks, turtles, and several amphibian species that have already begun to naturally populate the area. (1,2)

Overall, the improvements were intended to enhance the park's recreational offerings while strengthening the city's defenses against flood risks and water shortages. The local community will have a space to relax and enjoy various facilities, including an open-air auditorium, scenic viewpoints, an indoor pool, and a baseball field, among many other features.

Fjärdingsparken is a city park that has been constructed in two phases, the second finishing in 2023 [Ref. 1]. The initial phase of the plan focuses on building a new kindergarten, and it includes developing the park surrounding the kindergarten to increase locals' access to green space and recreation. The first phase also involved building a football field at the park's edge [Ref. 1, 4, 5]. The second phase continued the park's development focusing on rain water management and biodiversity. The park was constructed so that up to 900 m3 of rainwater can be managed in the park during a 100-year rain, protecting the surrounding area from flooding. This is part of a flooding strategy for the city. The park includes a meadow, aiming to provide habitat for flowers and plants supporting pollinators and butterflies. It also contains amenities such as an outdoor gym, a dog park, and a "play forest" designed for children. The climate impact of constructing the park was evaluated in an attempt to reduce GHG emissions [Ref. 1-3].

The Joe Louis Greenway is a 27.5-mile recreational pathway designed to create safe, connected, and equitable spaces throughout Detroit. It will link 23 neighborhoods across Detroit, Hamtramck, Highland Park, and Dearborn, connecting them to each other and to the Detroit riverfront. The greenway will transform a blighted, abandoned rail corridor into a park that runs through the heart of Detroit's communities. (Ref. 2, 3)
This project is guided by a Framework Plan funded by the Ralph C. Wilson, Jr. Foundation and shaped by extensive community input. Residents voiced a strong desire for the greenway to provide off-street recreation and increased access to green spaces across Detroit. Additionally, they advocated for the restoration and remediation of former industrial sites, which the Conrail section of the greenway will address. (Ref. 4) The design incorporates stormwater management to mitigate flooding, native meadow plantings to support bird habitats, and tree-lined paths for shade and improved air quality. The Framework Plan ensures the Joe Louis Greenway will transform infrastructure that once divided neighborhoods into one that unites them, reconnects natural systems, drives economic redevelopment, and fosters a resilient social network. (Ref. 13)
The concept originated in 2007 with the Friends of the Inner Circle Greenway local NGO and became part of the Detroit Greenways Coalition Network Vision in 2009. The Detroit Greenways Coalition Network Vision is a comprehensive plan developed by the Detroit Greenways Coalition (NGO), an organization dedicated to promoting non-motorized transportation and green infrastructure throughout the city. After years of advocacy and collaboration with the city of Detroit, the project’s route was finalized. In 2017, Mayor Mike Duggan announced the greenway would be renamed in honor of Joe Louis, the legendary boxer and Detroit native who championed African Americans' rights and symbolized social justice. (Ref. 1, 2,)

The Floating University was initiated in 2018 at the rainwater retention basin of the former Tempelhof airport in Berlin. Though not an official university, it serves as a space for transdisciplinary, communal learning, transforming an abandoned urban site into a vibrant community resource. The project reclaims the basin, hosting workshops and events that range from ecological lectures to cultural and art programs, fostering collaboration between diverse disciplines and communities.
The architecture collective raumlaborberlin originally envisioned the project as a six-month initiative. Artists, universities, and seminar groups contributed to designing the space and organizing workshops. However, due to its success, an NGO, Floating e.V., was established to sustain the project. Today, the NGO manages the site and continues its mission of engaging communities with urban and ecological themes.
After Tempelhof airport closed in 2008, the basin was infrequently cleaned, leading to contamination and sediment accumulation. Over time, a wetland ecosystem emerged, attracting plants, insects, birds, mammals, and amphibians. This natural development complements the Floating University’s infrastructure, which consists of open timber structures like a kitchen, art installations, communal spaces, vertical gardens, gardening beds, and an auditorium. These structures integrate seamlessly with the basin’s existing technical framework and wetland environment.
Floating e.V. aims to make the basin accessible to Berlin’s urban population while sparking discussions about urban climate, resource management, and water cycles through diverse and artistic programs. Smaller initiatives focus on specific ecological themes, such as plant diversity and soil health, through projects like a seed archive and soil lab.
The Floating University exemplifies how abandoned urban spaces can be revitalized into hubs for learning, creativity, and ecological awareness. (1-3, 8, 9)

The project aims to modernize Ciurchi Park, also known as "Tătărași Park," due to the degraded state of its current infrastructure (1 - 8). Initiated by the Municipality of Iași, the initiative seeks furthermore to increase the amount of green space per inhabitant in the city and reduce overcrowding in other parks, thereby diversifying options for citizens (1 - 9). Planning for the project began in 2022, and the bidding process for its execution was released in April 2024, which is still awaiting a decision (1, 2. 7).
The implementation is expected to involve interventions in existing green spaces, including the planting of 120 trees, 1,000 bushes, and approximately 2,000 species of flowers and ornamental plants. The project will also feature a monitoring program for tree species, management of existing vegetation to protect healthy trees, and removal of invasive or degraded plants (1, 2, 4, 8). Additionally, it will include benches, facilities for physical exercise, an underground waste collector, and a rainwater drainage system, among other infrastructure improvements (1 to 8).
The project is expected to be financed by the local budget and EU funds, with a total estimated cost exceeding 5,000,000 euros, including taxes (2, 4). It is included in the Integrated Urban Development Strategy 2015-2030 for the city (8, p. 12).
The goals of the project are to modernize the park, improve accessibility for citizens in the surrounding area, minimize management costs for the municipality, ensure a sustainable habitat for flora and fauna with minimal invasive interventions, and harmonize architectural proposals with the landscape (6, 8, p. 32). Other objectives include protecting biodiversity, enhancing the park’s aesthetics and the overall city environment, and reducing CO2 emissions, which will ultimately improve the quality of life for surrounding residents (8, p. 141).

The renovation of the "Marechal Humberto Delgado" Square focused on transforming the area into a more pedestrian-friendly and sustainable urban space. The project included reorganising the traffic system, creating a new urban green square, requalifying the bus terminal, enhancing the integration of different transport modes and improving pedestrian access (Ref 1). Key features of the intervention were the introduction of cycle paths, wider sidewalks, green spaces with 200 new trees, and recreational facilities such as a children's playground and water features (Ref 2). The project also addressed critical infrastructural needs, including constructing a rainwater collector as part of Lisbon's General Drainage Plan to mitigate the city's frequent flooding issues (Ref 3). The renovation, completed in 2024, was part of the 'A Square in Every Neighborhood' program, emphasizing community involvement and sustainable urban development (Ref 3).

The Detroit RiverWalk is an urban development project along the Detroit River, designed to reconnect residents with their waterfront and revitalize a historically industrial area. Once characterized by abandoned buildings and industrial debris, the riverfront between the MacArthur and Ambassador Bridges had long been inaccessible to the public. To address this, the Detroit Riverfront Conservancy was established in 2003 to lead the redevelopment of this space.
The RiverWalk currently stretches along a 3.5-mile section, with plans to expand to 5.5 miles, integrating ecological restoration, public access, and recreational opportunities. The esplanade features native landscaping, artistic elements, and amenities, including four pavilions, a custom carousel, and areas for fishing, walking, biking, and inline skating.
Environmental remediation has been a crucial part of the project. In collaboration with the U.S. Environmental Protection Agency’s Great Lakes National Program Office, the Detroit Riverfront Conservancy successfully cleaned up 13,000 cubic yards of contaminated sediment, significantly reducing pollution and contributing to the removal of the Detroit River from the list of the most polluted sites in the Great Lakes. Furthermore, the project also includes greenways, park creation and revitalization.
The RiverWalk is not just a public space; it symbolizes Detroit’s transformation from a Rust Belt city to a sustainable urban environment. It exemplifies the power of public-private partnerships in revitalizing urban areas. The RiverWalk continues to expand, with plans to connect various parks and extend to the Ambassador Bridge, further enhancing the city’s waterfront. Its success was recognized in 2021 when it was named the Best Riverwalk in America by USA Today, cementing its status as a model for urban renewal and community engagement. (Ref. 1, 2, 3, 4)

Salines Beach, a popular destination for over a million visitors annually (Ref 9), is facing severe erosion due to rising sea levels and poor coastal management. Since 1995, the beach has lost more than 20 meters in width. This loss has been worsened by vehicle traffic and the introduction of coconut trees in the 1950s, which reduced the native root systems that once helped to stabilize the coast (Ref 5). Now, the encroaching sea threatens to swallow the road that runs along the beach.
In response, the Salines Conservation Committee—comprised of concerned community members and environmental groups—has been advocating for urgent action to halt the erosion. They have called for a renaturalization of the area through the replanting of endemic species and restrictions on car traffic, both aimed at restoring the beach’s natural resilience.
When part of the road collapsed in July 2022, the committee took immediate action, organizing community-based interventions. These efforts included blocking traffic, raising public awareness, and planting over 60 endemic plants in the damaged area. The aim was to reestablish a root network capable of anchoring the coastline and capturing shifting sands (Ref 1; 2). The intervention was described as "a response to the urgent need to rebuild the root network, an ecological engineering solution recognized as the most effective method for retaining beach sand and slowing coastal erosion" (Ref 2; 1). The intervention on this section of the coast was first completed, then discarded by the municipality of Sainte-Anne (Ref 2). Regional and National agencies are currently undertaking the restoration works but it is unclear the stage of completion (See Ref 3).