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

Bayou La Batre, also known as the seafood capital of Alabama, has been facing severe flooding problems, including the occurence of combined sewerage overflows. The Nature Conservancy has secured funding to install a green stormwater project in Bayou La Batre, adjacent to the library, sports fields and the community center. Alongside the aim of the green stormwater project to decrease flooding events in the community by infiltrating water, it also serves as an education and engagement project [1]

In 2012, PRZHT (Pôles Relais Zones Humides Tropicales) initiated Project REMA, an effort dedicated to the conservation and rehabilitation of ponds in the Antilles, with backing from the IUCN. Wetland ecosystems in Martinique and the Caribbean had long been overlooked. However, interest in these habitats grew after PRZHT introduced an interactive virtual tour of Antilles ponds in 2019. Project REMA emerged in response to local concerns about the lack of technical resources for pond restoration in the French West Indies. While similar initiatives had been undertaken in France, there was no specific guide tailored to this region. Though originally conceived in 2012, the project remained dormant for several years before fully launching in 2019. Between 2019 and 2021, restoration experiments were conducted on 12 ponds across Martinique, Guadeloupe, and Saint-Martin, laying the groundwork for a comprehensive technical manual.
Building on this success, REMA II was introduced in January 2024 with a three-year scope. This new phase will focus on restoring and maintaining 80 ponds, both public and private, in Martinique and Guadeloupe. Additionally, it will address the management of invasive species and incorporate eDNA analysis to enhance conservation efforts. These small wetlands play a fundamental role in flood regulation, water storage, pollutant filtration, erosion control, and carbon absorption. They also provide refuges for biodiversity and contribute to the resilience of territories in the face of climate change.
(1, 2, 3)

The Liberties is one of the most recognizable urban areas in Dublin and Ireland, strongly associated with old Dublin, working-class communities, and the brewing and distilling industries. While rich in history, cultural significance, and local stories, The Liberties faces numerous placemaking and quality-of-life challenges. The area continues to experience significant dereliction, a fragmented urban fabric, and a shortage of high-quality green spaces. For instance, tree coverage in The Liberties is sparse, with good-quality street trees only found in a few small areas, such as Gray St. and Reginald St., along the South Quays, Cornmarket, and near the fountain on James St. The area has approximately 1,200 trees, amounting to less than 5% canopy coverage.
In response to these challenges, Dublin City Council enacted The Liberties Greening Strategy in 2015. Building on the Liberties' Local Area Plan, this strategy aims to develop a network of new urban parks, improve access to heritage green spaces, and refurbish existing parks and play areas. It addresses multiple goals, including ecological connectivity, water management, flood risk reduction, air quality improvement, social cohesion, environmental education, and public health. This strategy is an initiative of the Parks and Landscape Services Division of Dublin City Council, in collaboration with the South Central Area Office and with input from Áit Urbanism + Landscape and Mary Tubridy & Associates.
Since its implementation in 2015, the strategy has resulted in the development of two new community parks, enhancements to several green spaces, and the greening of public spaces. It has also introduced measures to support food production in community gardens and allotments, revitalize ecosystems, strengthen water management, improve air quality, boost carbon sequestration through tree planting, divert water from the local sewer network, prevent flooding, and regulate heat. (1, 2, 3)

Pollution from roadways is often carried by rainwater into gullies, which then direct this runoff to the nearest watercourse, ultimately polluting local rivers and degrading water quality (1). To address this issue, Dublin City Council is exploring potential green infrastructure solutions to reduce roadway pollution in rivers, focusing on nine pilot sites within the Dodder catchment area (1). Green infrastructure has the advantage of treating pollutants before they enter rivers or watercourses, which can significantly improve water quality in the area (1).
In addition to enhancing water quality, green infrastructure helps manage flood risks by slowing water flow to rivers, which can lessen the frequency and severity of flood events (1). These green spaces also foster biodiversity, creating more pleasant and ecologically supportive environments for the community (1). As an added benefit, green infrastructure serves as an important climate change adaptation strategy (1).
Upon completion of these pilots, Dublin City Council plans to expand successful methods to other locations across the city and potentially further afield (1). The project will involve creating new green spaces, enhancing existing ones, and transforming certain hard surfaces, all of which will contribute to protecting the Dodder and Santry rivers. By treating roadway runoff before it reaches the rivers, the initiative will also offer valuable benefits to the local community (2).
The proposed changes will be designed to support health and well-being, provide informal play areas, attract desirable wildlife, reduce flood risks, and help urban areas adapt to the impacts of climate change (2). The Council also plans to monitor the performance of these green infrastructure measures to assess their effectiveness in filtering pollutants from roadway runoff (1).

The likely impacts of climate change in South Dublin County include an increased risk of flooding, more frequent summer droughts, deteriorating air and water quality, and biodiversity loss (1). To address these climate challenges, the county developed the County Development Plan 2016-2022 as part of the South Dublin Climate Action Plan, aiming to establish a comprehensive legislative and policy framework for green infrastructure (GI) planning (1).
The plan outlines various objectives, including creating a coherent, integrated, and adaptable GI network across South Dublin County. One key initiative is the establishment of native mini woodlands throughout the city, designed to form strategic links and integrate the GI Strategy’s objectives into all relevant land-use plans and development across the county (1).
The purpose of these mini woodlands is to connect green spaces across the city (minimum size of 100 sq m), sequester carbon, and promote biodiversity in suitable locations, such as built-up areas, low-grade parkland, and other zoned areas deemed appropriate (1). Given the long time required for tree growth, the project employs the Miyawaki method, planting a high density of diverse native species to create mature forests up to ten times faster than traditional plantations (2). These forests are estimated to host 20 to 100 times more biodiversity and absorb carbon up to 40 times more effectively, without the use of chemicals or fertilizers; key factors include ground preparation, planting density, and species diversity (2).
In 2022, the project held a planting day for the mini woodlands initiative on Mill Lane, where 1,200 native trees and shrubs were planted with the help of volunteers from local schools, the community, a corporate group, and the Mayor of South Dublin, Councillor Emma Murphy (2).

Lisbon is facing an increasing threat linked to climate change due to its geographical location and climate (6), which has had a negative impact on health and quality of life in the city (5). Its average annual precipitation is decreasing, although the city experiences more winter precipitation. This results in longer droughts and more seasonal flooding, which reduces water retention and soil conservation (6). Average temperatures are increasing by 14°C per year, with maximum temperatures up to 5°C higher (6).
As an adaptation measure to these challenges, the LIFE LUNGS project aims to increase Lisbon's resilience by implementing green infrastructure and promoting related ecosystem services (1, 3, 5, 6). Thus, it focuses on measures aimed at coping with temperature increase, mitigating the effects of heat waves and water scarcity, which are expected to become more frequent, being in line with the climate policies adopted by the municipality. The project runs from 2019/2020 to 2024/2025 (1, 5, 6). It aims to address cross-cutting issues such as climate, water and biodiversity (3). The project expects to work hand in hand with the City of Malaga, which has been developing projects aimed at adapting the city to climate change. It is expected to replicate the work in Malaga and post-project to 2 national territories, and 1 in the EU (4). It is also intended to transfer the project work to be implemented in private areas that are part of Lisbon's green infrastructure, and to disseminate and technically train municipalities of the Lisbon Metropolitan Area and other municipalities committed to climate change adaptation (4).

In 2018, the City of Detroit implemented a drainage charge to help cover the costs of capturing, conveying, pumping, treating, and safely returning combined sewage to the Detroit and Rouge Rivers (1). The charge is calculated based on each parcel’s impact on the sewer system, particularly by measuring impervious acreage (1). Since then, this fee has posed significant challenges for one group in particular: Detroit’s houses of worship (2). Churches, with their large roofs and parking lots, face higher monthly drainage charges, creating financial strain for many faith leaders (2).
To support these institutions, Sacred Grounds has been providing grants, labor, and design assistance to install projects that reduce water bills and drainage fees (2). Sacred Grounds collaborates with the National Wildlife Federation, Friends of the Rouge, and Sierra Club of Michigan to implement these projects through the city’s green credit program (2). A recent initiative involved installing four rain gardens located on the perimeter of St. Suzanne Our Lady Gate of Heaven Church (3). These bioretention gardens, funded by several private and public actors and led by Detroit Future City, diverts water from 20 large downspouts, redirecting an estimated 500,000 gallons of runoff annually away from the municipal sewer system (3, 4).
In addition to managing water, the gardens foster a thriving habitat for pollinators and adds beauty to the area (3). St. Suzanne’s commitment to environmental education includes engaging over 130 youth and adults in training programs that build pathways to STEAM careers and opportunities where local residents are often underrepresented (4). The church also features an innovative, eco-friendly outdoor classroom developed by students, further supporting their sustainability mission (4).

Sri Lanka faces multiple natural hazards, including tropical storms, flash floods, and landslides. As the country's urban population has grown, development projects have encroached on wetlands, compromising their natural flood protection, air and water purification, and carbon storage capabilities. Additionally, hilly regions are at risk of landslides, particularly during the monsoon season, posing significant threats to vulnerable communities (4).
To address these challenges, the World Bank and the Sri Lankan government collaborated on the Metro Colombo Urban Development Project. This initiative focused on nature-based solutions (NBS) as cost-effective and sustainable approaches to risk management (4). By strengthening natural processes and ecosystem services, the project aimed to mitigate hazards such as floods, erosion, and landslides (4). Technical assessments by the World Bank highlighted the importance of wetlands in flood protection, leading to efforts to protect and restore 20 square kilometres of freshwater lakes, wetlands, and swamps (1, 4).
The project supported the Sri Lankan government in reducing flooding in the Colombo Water Basin and enhanced local authorities' capacity to manage infrastructure and services. It prioritised metropolitan investments to mitigate the physical and socioeconomic impacts of flooding and aimed to build long-term capacity for urban management and local service delivery (6).

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].

The Waliwa project, launched in 2017 by the municipality of Sainte-Luce, is a collaborative effort dedicated to restoring marine biodiversity, enhancing the ecological balance of the bay area, revitalizing the local ecosystem and supporting sustainable economic activities. By focusing on marine biodiversity conservation, Waliwa addresses several critical environmental challenges. The project helps mitigate coastline erosion, support the blue economy through artisanal fishing and tourism, and foster an environmentally friendly culture among the local community.
So far, the Waliwa project has implemented three initiatives: it restored the Gros Raisin backshore to address erosion and provide nesting sea turtles with protected space (Ref 4). The project also intervened to restore the Pont Café pond, which was covered in Salvinia Molesta, preventing the intake of oxygen and hampering its role as a water filter, habitat for species and flood regulator .
Furthermore, the project has conducted studies and raised awareness about the challenges posed by wastewater management on the health of municipal water bodies. Through these efforts, Waliwa is working to create a more sustainable and resilient marine environment for future generations. (Ref 4, 5, 6; 12)