Expected increased protection against flooding

The requalification project for Viale Buoncammino in Cagliari aims to revitalize the historic promenade while preserving its original layout and functions. Launched in September 2022 and completed in 2023, the project focused on enhancing the area’s aesthetic and environmental appeal. Key improvements include expanding green spaces by adding 560 new square meters, enhancing vegetation, and reducing surface runoff. This involves increasing permeable surfaces around existing trees to boost natural vegetation, improve bioclimatic comfort, and manage runoff during heavy rains.

The project also includes reconstructing pavements, optimizing seating areas, and repositioning urban furniture for better functionality and aesthetics. A modern LED lighting system will be installed to reduce energy consumption and operational costs, supporting the project's sustainability goals. The area is included between via Anfiteatro, viale Buoncammino and viale Giussani and also includes the squares F.Pilia and Marongiu-Pernis. The project aims to restore Viale Buoncammino as a dynamic social and cultural hub in Cagliari, appealing to both residents and visitors. (Refs. 1, 2, 3 & 4).

In the city of Ciudad Juárez, the municipality, in collaboration with UN-Habitat, aims to design and create a park that encompasses the yards and unmaintained areas surrounding the railway station, transforming these spaces into an accessible and safe public area. This project covers over 500,000 square meters and addresses not only degraded areas but also several public squares. Described as "a coordinated urban recycling strategy," this initiative seeks to repurpose existing public squares and rehabilitate neglected spaces into vibrant green areas that feature universal accessibility, native vegetation, and urban furniture designed to enhance safety. The project also aims to provide increased recreational opportunities, improve permeability, and introduce additional shaded areas. A key component of improving permeability involves the restoration and incorporation of acequias—traditional historical irrigation systems that absorb and manage excess rainwater, thereby reducing the likelihood of flash floods.
Additionally, the project focuses on the restoration and promotion of significant historical buildings, such as the old railway station and the whiskey factory, integrating them into a larger cultural and sports facility area at the municipal scale. The overarching goal is to revitalize the site through effective coordination with the relevant authorities responsible for the spaces adjacent to the railway station, stretching from Plaza Misión de Guadalupe to Blvd. Municipio Libre. This collaborative effort aims to accommodate both sports and cultural facilities while also creating a green corridor.
Furthermore, the project intends to reforest, redesign, and enhance Plaza Misión de Guadalupe, Plaza Monumento a Benito Juárez, and other residual public spaces and gardens. This initiative aligns with its Public Space Strategy, which emphasizes the development of gender-inclusive and resilient public spaces.(Ref 1, 3, 4).

An old park in Gothenburg was renovated to become "the world's best park when it rains" and attract visitors all year round. Rainfall is common in Gothenburg, but more importantly, the amount and intensity of rain are expected to increase in the future due to climate change. Municipal real estate company Higab had the park renovated to make the entrances more accessible and show that the park is open to everyone. A few rain gardens were created to better take care of rainwater, as well as a roof and sculptures interacting with the rain for aesthetic purposes. Additionally, existing plants and trees were cared for, and new ones were planted to create varied vegetation year-round. The area has been a park since 1860, therefore, efforts were made to preserve the historical space, such as using necessary amenities (benches, light sources) as well as improve the ecological function of the park. Special care was taken not to damage grown trees, such as the cherry trees, which blossom in the spring and are a popular attraction [Ref. 1, 2, 4, 5]

Brookley by the Bay is a 98-acre new waterfront park project along Mobile Bay's western shore (Ref 1). The park aims to reconnect people with the Mobile waterfront and coastal ecosystem (Ref 2). The area, once an abundant mosaic of tidal marshes, forested wetlands, and shallow lagoons, became a port, leading residents to lose contact with the natural landscape (Ref 2).
The park serves both recreational and environmental purposes, aiming to create and restore areas that enhance habitat resilience and allow coastal ecosystems to thrive (Ref 1). It features sports facilities, including kayaking, volleyball, golf, and biking, along with social gathering and educational spaces such as an amphitheatre lawn, a performance pavilion, and picnic tables (Ref 3, Images 1-3). The park provides safe and equitable access for all Mobile residents to nature, beaches, tree canopies, open fields, and varied shorelines, all connected by pedestrian and bike lanes (Ref 2). The project also focuses on habitat enhancement and restoration for biodiversity (Ref 3, Images 1 & 4), as well as flood protection through shoreline get-downs, vegetated edges (Image 4), and undulating berms and swales that serve as a layered protection system against stormwater and coastal flooding (Ref 2).
The development of Brookley by the Bay was guided by input from over 300 community members (Ref 1), local stakeholder organizations, and project partners, with the goal of establishing a more resilient, accessible, and enduring space for generations to come (Ref 2).

The Rain Garden 2.0 project at Gdańsk University of Technology is an innovative green infrastructure initiative that manages and purifies rainwater while enhancing biodiversity. Part of the international NICE (Nature-based solutions for urban climate adaptation) initiative, this project serves as a living hub for testing solutions to address urban climate challenges. Opened in July 2023, the rain garden exemplifies a multifunctional approach to water retention, pollutant filtration, and urban biodiversity support. It is located behind the Faculty of Chemistry's Building C and has a capacity exceeding 11 cubic meters. (Ref. 1; Ref. 6)
The garden, designed by researchers from the Faculty of Civil and Environmental Engineering under the leadership of Prof. Magdalena Gajewska, captures rainwater runoff to prevent urban flooding and mitigate the strain on storm sewer systems. It absorbs pollutants, improves water quality, and supports over 1,100 hydrophyte plants, creating a natural solution for heavy rainfall events.
Beyond water management, the garden contributes significantly to urban biodiversity. Its moist soil and diverse plant species—designed to thrive in a range of conditions—help create habitats for insects and other small wildlife, boosting ecological resilience. (Ref. 1)
The rain garden’s innovative design consists of several key components. The first stage channels rainwater into reservoirs, reducing the energy of inflowing water. Subsequent parts purify the water through sedimentation processes, effectively filtering out pollutants such as those from streets and roads. Early research shows that these purification methods work exceptionally well, retaining a broad spectrum of pollutants before the water reaches the garden’s main basin. The project also benefits from cutting-edge laboratory equipment, allowing for detailed monitoring and analysis of water quality. (Ref. 1)

The Three Mile Creek Watershed project is part of the City Council watershed management plans (Ref 2) to stabilize the banks and the stream along the Twelve Mile Creek and Langan Park Lake, both of which drain into Three Mile Creek and Mobile Bay (Ref 1). The project aims to address the issues of degradation of the banks and destabilization of the creek, undercutting of sanitary sewer crossings and sedimentation in the creek and Langan Park Lake because of the increased water flow speed due to stormwater conveyance (Ref 2). Besides, major pollutants from run-off and sewage water contribute to the degradation of Three Mile Creek (Ref 5). Key initiatives include stabilizing the banks and streambed of the Twelve Mile Creek, dredging and restoring Langan Park Lake, and implementing instream structures to reduce erosion and protect infrastructure (Ref 2). The project also emphasizes reducing pollutants from stormwater runoff, improving water quality, and helping to protect the area’s estuarine and marine water resources (Ref 1). The project will increase natural habitat and contribute to regulating biodiversity by aiding in the abatement of invasive species such as the apple snail (Ref 2). It is expected to contribute to enhancing recreational access through the development of trails, educational programs, and water sports facilities. The overall goal is to restore ecological health, support flood control, improve the quality of life in the Mobile and Prichard communities and make the Three Mile Creek a recreational destination (Ref 6).

Cagliari's waterfront is currently characterized by extensive soil sealing, which has rendered the soil impermeable, leading to a loss of biodiversity and contributing to the urban heat island effect. Additionally, the waterfront is disconnected from the city due to heavy traffic. In 2023, the Municipality of Cagliari launched the "Green Promenade for Cagliari’s Seafront" project, aimed at revitalizing the waterfront and reconnecting the city with its coastal heritage. Led by Stefano Boeri Architetti, the project seeks to transform the area into a continuous green space that integrates pedestrian pathways with shaded public areas, functioning as a "green lung" to mitigate urban heat and enhance biodiversity.
The initiative will introduce over 200 new trees and 5,700 square meters of green space, creating a park that beautifies the area, improves air quality, and lowers local temperatures. A key focus of the project is fostering cultural and social inclusion by developing new community hubs that encourage diverse activities and strengthen social cohesion. Additional features include recreational areas, sports fields, and outdoor seating. (Ref. 1, 2,3)
The project also aims to enhance social inclusion, environmental sustainability, and urban connectivity, ultimately transforming the waterfront into a vibrant public space that reflects Cagliari’s identity.
However, the lengthy construction process has disrupted local businesses and reduced foot traffic, making the area less attractive during the redevelopment phase. (Refs. 10, 11, 12 & 13).

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 Gårda pilot rain garden has been constructed as part of the research project Innovative Rain Gardens at Chalmers University of Technology in Gothenburg. In addition to causing flooding, runoff rain water in urban environments can be contaminated with microplastics, organic pollutants and metals which can spread into the natural environment. Yet, most of the storm water in urban environments is not treated. The purpose of the Innovative Rain Gardens project is to research the ability of a pilot rain garden to treat such pollution. The project acknowledges the function of a rain garden to prevent flooding, but in this study only the pollution treatment potential is investigated. The pilot rain garden was constructed next to the E6 highway in central Gothenburg [Ref. 1-4]. It includes several different bioretention filters where selected plants are grown in filters containing different materials such as biochar, ash and soil [Ref. 2, 3]. Results so far show that the use of rain gardens can significantly reduce pollution. However, further research is needed to determine the long term function of the bioretention filters and the potential of scaling up the NBS. The project is funded by the Swedish Research Council for Sustainable Development (Formas), IMMERSE - Implementing Measures for Sustainable Estuaries, an Interreg project supported by the North Sea Programme of the European Regional Development Fund of the European Union, and COWIfonden (private foundation) [Ref. 1-3].

The Juan Angola River is an urban channel included in the system of rivers and channels of Cartagena, and it connects the Ciénaga de la Virgen wetland and the Bay of Cartagena, facing similar issues as the Cienaga de la Virgen such as illegal occupation of its shores, illegal waste dumping, deforestation of mangroves, and pollution. The recovery plan for the Juan Angola River is led by the EPA Cartagena (Environmental Protection Agency), with the support of other institutions, aiming to restore the Juan Angola’s ecosystem. This includes targeting the mangrove forest, dredging the natural channel, and delineating buffer zones with urban infrastructure to create public recreational spaces. The activities involve relocating people illegalling cupping informal settlements from the river shore, moving an existing bridge (the Benjamín Herrera bridge) which obstructs the current, recovering the low tide and riverbed areas, building pedestrian paths, clean the riverbank, recover mangrove areas and establish programs of education and environmental awareness (ref 1 and 2).