Water management (SDG 6)

The project, implemented by the municipality of Cagliari, involves the creation of a new garden in 2021 on Via Eroi d’Italia, in the Pirri municipality, located about 5 km from the center of Cagliari. This initiative is part of a broader effort to reclaim degraded urban green spaces. The garden spans approximately 900 square meters and was previously an unused lot serving as a parking area. Its transformation required substantial groundwork, including soil scarification and leveling, to prepare the area for its new purpose. The garden is now enclosed, with pedestrian access via two gates leading to a paved walkway.
Inside, the garden is divided into two main sections: a children's play area and a landscaped green space. The play area covers about 100 square meters and features durable artificial grass, swings, a spring toy, a universally accessible table, a children's table, benches, and a multi-compartment recycling bin. The green space, approximately 200 square meters, is planted with low-water-use grass and surrounded by drought-resistant plants like albizia, oleander, and lantana, chosen for their low water consumption and resilience to environmental stress. An underground irrigation system, linked to a 5,000-liter water tank, ensures efficient water use.
The remaining 600 sqm outside forms a parking area with 1 disabled space, 2 motorcycle spaces, 1 bicycle rack, and 15 car spaces.
The garden also incorporates sustainable elements, such as LED lighting for energy efficiency and a mural by renowned Sardinian artist Manu Invisible, depicting sunlit forest undergrowth in shades of green. This project responds to citizens' requests and prioritizes resource efficiency by reducing hazardous substances and minimizing waste. The materials used, including recycled plastics, and the selection of plants were chosen to match local ecological conditions, enhancing the garden's sustainability and reducing its environmental impact (Refs. 1, 2, 3, 4 & 5).

In the 1980s, rapid industrialization, urban population growth, and increased water usage led to severe pollution in Dianchi Lake, exceeding its environmental capacity and significantly degrading its water quality (Ref 1). This deterioration had serious effects on nearby ecosystems, including Cuihu Lake (Ref 2). Cuihu Lake (翠湖), also known as Green Lake Park, is a well-known park and body of water in the center of Kunming, Yunnan Province, China. In Cuihu lake the decline in water quality caused a sharp reduction in native species like the golden line barb, which depend on the local ecosystem for survival, pushing them to near extinction and destabilizing the entire ecosystem (ibid.).
To address this, several effective initiatives have been launched to restore Cuihu Lake’s ecosystem in recent years (Ref 2, 3). One of them was started in 2020 when a restoration project was initiated by the site's administration in collaboration with Dr. Li Weiwei’s team from the Kunming Institute of Zoology, Chinese Academy of Sciences. The project focused on creating micro-habitats and restoring the aquatic ecosystem (ibid.). Ecosystem and biodiversity restoration efforts were conducted across a 5,000 m² area on the east side of Green Lake Park, covering approximately 1/27th of the lake (ibid.).
As a result, more than 20 aquatic animal species are now thriving and contributing to water purification, while three submerged plant species cover over 50% of the project area (Ref 2, 3, 4). Bird diversity and numbers are also increasing, with species like white-breasted kingfishers, green-winged teals, and crested guinea-fowls returning to the area (ibid.). Additionally, there has been a significant improvement in water quality (ibid.).

The Three Mile Creek Hydrological Restoration project is taking place in one historic channel of the Three Mile Creek, located east of Dr. Martin Luther King, Jr. Avenue, and covering approximately 1,800 linear feet (Ref 3). This project, led by the City of Mobile, aims to remove sediment from the stream channel. This segment of the Creek was bypassed with a straight channel in the early 1980s to control flooding in the area, thus accelerating the accumulation of sediments in the historic channel (Ref 1).
The project's goal is to restore and maintain the natural flow to the historic channel and create a connection to the City and County's Blueway initiatives (Ref 3). This will improve habitat conditions and water quality and help to protect the area’s estuarine and marine water resources (Ref 8). It will also contribute to revitalizing the Three Mile Creek Watershed and provide increased recreational opportunities for citizens, like kayaking and canoeing (Ref 6). Construction work occurred in 2022 and 2023 (Ref 3).
The Three Mile Creek Hydrological Restoration is a key component of the Mobile Bay Shore Habitat Conservation and Acquisition Initiative, which focuses on acquiring, restoring, and preserving habitats, including riparian, wetland, and upland areas that support various fish and wildlife species affected by the environmental disasters of the Deepwater Horizon oil spill that occurred in 2010 (Ref 1). The project spans three critical areas: 450 acres within the Three Mile Creek Watershed (as detailed in this project profile), 300 acres in the Dog River Watershed, and 40 acres of bay shore property in the Garrows Bend Watershed (with the latter two areas being part of separate initiatives) (Ref 4).

The "Recuperación del Laguito" project aims to restore El Laguito, a coastal water body in Cartagena, Colombia, severely affected by sedimentation that blocks natural water exchange with the Caribbean Sea. This blockage has led to stagnant, low-oxygen water, degrading water quality and aquatic ecosystems (ref 1). The project seeks to restore El Laguito’s environmental and social functions by reestablishing seawater flow, reducing sediment impact, improving water quality, and reviving the ecosystem. Additionally, it aims to provide data to guide long-term solutions for sustainably managing this community resource (ref 1).
The project is a response to recurring ecological crises, such as frequent fish die-offs due to low oxygen levels. Local residents initially took matters into their own hands, manually attempting to reopen the channel. The formal intervention started following a 2019 directive from the Ministry of Environment and Sustainable Development, outlining a phased strategy: short-term installation of an axial pump for water exchange, medium-term studies for a permanent fix, and long-term construction plans (ref 3). Currently, the project involves using heavy machinery to clear sediment and allow seawater inflow, supported by the Gobernación de Bolívar, Cardique, and the Cartagena Mayor's Office. This phase serves as a transitional step towards a more sustainable, permanent solution (ref 2). The project’s impacts focus on ecological restoration. Short-term benefits include better oxygenation, reduced harmful algal blooms, and revived marine life. Long-term goals encompass sustainable water management, ecosystem stabilization, tourism enhancement, and the development of recreational and sports facilities in harmony with environmental conservation (ref 4).

Maskinparken is a new park covering 3700 m2 in the Lindholmen district, a new neighbourhood in a previous industrial/harbour area [Ref. 5]. The park is described as a well-needed green oasis or green lung in the developing area. The park finished construction in 2022 and is intended to provide access to green space for people living and working nearby. It is also designed as a blue-green stormwater management solution, where about 500 m3 of rainwater can be stored in the lower areas during heavy rainfall. Stormwater will be leaked from surrounding grey areas to the park to protect them from flooding. The Swedish National Board of Housing, Building and Planning (Boverket) has highlighted the park as a good example of climate adaptation in urban planning. The park has a variety of plants such as different tree species and flowering meadows, and plants that can withstand being soaked in the lower areas. Plants can grow in different landscape structures, such as hills and a pergola. The park also has amenities such as benches and lights, which are designed to mirror the style of the surrounding, older industrial brick buildings [Ref. 1-4].

Two new wetlands were established in Dodder Valley Park as part of the Dublin Urban Rivers Life Project (DURL). This project aimed to create integrated constructed wetlands (ICWs) at strategic locations in South Dublin County to purify wastewater and storm-water before it discharged into rivers.
The ICWs consisted of a series of cells resembling shallow ponds, typically 200 to 300 mm deep. Heavily planted with specific vegetation, these cells treated water by removing nutrients and harmful impurities, resulting in cleaner, purer water being discharged. The water flowing into the wetlands came from wastewater of misconnected appliances and storm-water pipes located under public roads, which collected rainwater from roads, footpaths, and the roofs and patios of houses.
These wetlands also provided important benefits, including flood alleviation, bioretention of particulates and nutrients, improved habitat conditions, and enhanced biodiversity. The project aimed to promote the relationship between green infrastructure and public well-being, creating a complex biological system that supports a diverse range of plants, animals, microorganisms, and hopefully attracts frogs, newts, and birds.
To increase native biodiversity, the wetlands were designed with pollinator-friendly plants and trees, making them visually appealing for park users and the public. A Wetland Planting Day took place on September 9, 2022, with over 40 participants, including residents and representatives from local organizations. This phase of the project fulfilled not only the objectives of the LIFE project but also those of the River Basin Masin Management Plan 2022–2027, the Water Framework Directive, the Climate Change Action Plan, the Floods Directive. (1, 2, 5)

The municipality of Ciudad Juarez, in collaboration with UN-Habitat, has drafted a redevelopment strategy for an area known as "Paso de Oñate." This intervention falls within the broader framework of "Vision Ciudad Juarez 2040." The plan involves constructing a forested green belt along the southern edge of the Rio Grande (/Bravo) in the northwest part of Juarez, bordering the USA.
Currently in the planning stage, the project aims to restore the ecological function of various degraded areas along the Rio Grande, transforming them into a continuous, green, walkable, and recreational space. The strategy includes allowing vegetation to recover, introducing native plant species, and increasing tree cover to rehabilitate unmaintained parks, derelict areas, and degraded riverbanks. These areas will be equipped with new features and integrated with existing parks, schools, and playgrounds. The envisioned green corridor will enhance walking conditions, improve the perception of safety, offer recreational opportunities for all age groups, and deliver valuable ecosystem services such as temperature regulation, improved air quality, and water retention.
In addition to its ecological goals, the project has a historical and geographical dimension. It aims to incorporate cultural heritage elements, such as the monument of the New Citizen, Paso de Oñate, Turtles Park, and the beginning of the Acequia Madre. It will also connect with other green space initiatives, including the Mega Park "El Chamizal" and the "Corredor Cultural," which runs through the city center.
This intervention is being prioritized due to the area's ongoing social and ecological decline. Paso de Oñate is a critical border crossing point, which negatively affects mobility and air quality. The area also suffers from a high concentration of vacant housing, which contributes to the residents' perception of insecurity. (Ref. 1, 2, 3, 4)

Berlin has faced severe water shortages in recent years, with ponds, small lakes, and pools suffering significantly. Many have dried out or disappeared, causing habitats for countless animals and plants to vanish. Urbanization exacerbates the issue, as more areas become sealed, preventing rainwater from replenishing soil and water bodies. Recognizing the urgency, Berlin introduced the Eco-Account, a strategic reserve of areas and initiatives to mitigate the effects of urban development on nature and landscapes. Central to this is the Blue Pearls for Berlin program, focusing on revitalizing small water bodies to restore biodiversity and ecological balance.
The project identified approximately 30 ponds, pools, lakes, and ditches from over 100 candidates to be transformed into "blue pearls." These revitalized areas will support local ecosystems and improve Berlin’s water cycle. The Berlin Rainwater Agency, alongside departments responsible for nature, climate protection, and water management, is spearheading the initiative in collaboration with the Berlin Nature Conservation Foundation.
Two pilot sites—the Schleipfuhl/Feldweiher water complex in Marzahn-Hellersdorf and the Lankegrabenteich in Steglitz-Zehlendorf—were prioritized for restoration in 2024. These efforts include improving water quality and creating diverse habitats for wildlife. Enhancing small water bodies not only provides a refuge for animals and plants but also contributes to climate adaptation. Restored ponds and lakes can cool surrounding areas and improve the urban microclimate by utilizing locally accumulated rainwater. Blue Pearls for Berlin, approved by the Senate in 2022, aligns with the city’s Eco-Account framework, ensuring that these restored blue spaces offset ecological damage caused by infrastructure and urban projects. The initiative offers Berliners new ways to experience nature, fostering a balance between development and environmental preservation. (Ref. 1, 2, 4, 6, 7)

"The Neighborhood, Environment & Water Research Collaborations for Green Infrastructure (NEW-GI)" project in Warrendale, Detroit, aims to advance green stormwater infrastructure (GSI) knowledge and practice in legacy cities by integrating research on water quality, community well-being, governance, and ecological design. This collaborative effort, involving community members, government entities, and academic researchers, seeks to develop evidence-based strategies for sustainable stormwater management while enhancing urban landscapes and improving residents' quality of life.
In its first phase (2014-2015), the project created bioretention four bioretention gardens, each on two vacant residential properties in the Warrendale neighborhood. in Detroit's Warrendale neighborhood. These sites, constructed by the Detroit Water and Sewerage Department (DWSD) on vacant lots owned by the Detroit Land Bank Authority (DLBA), were monitored for water quality, and resident surveys were conducted to gauge the gardens' impact on neighborhood satisfaction and stormwater management.
The second phase (2016-2019) expanded the scope to refine GSI designs to reduce maintenance needs and further assess their effects on water management and community well-being. It also explored governance structures that impact GSI success, both in Detroit and other legacy cities, contributing to the development of guidance documents for GSI planning and decision-making.
Funded by the Fred A. and Barbara M. Erb Family Foundation, the NEW-GI project represents a transdisciplinary approach to urban ecological challenges, offering valuable insights into how GSI can deliver both environmental and social benefits in cities like Detroit.
(Ref.1,2)

The D'Olive Creek Restoration project is designed to address the significant environmental challenges facing the D’Olive Creek Watershed and its tributaries (Tiawasee and Joe’s Branch), primarily caused by increased urbanization. Over the last several decades, the area has experienced severe erosion, sedimentation, and habitat degradation due to stormwater runoff from new residential and commercial developments. This runoff has led to stream channel instability, loss of wetlands, and impaired water quality in both D'Olive Creek and Mobile Bay, threatening aquatic and wildlife habitats (Ref 2).
The project involves restoring degraded streams and implementing management measures to reduce the downstream impacts within the watershed. Key activities include stormwater retrofits, stream restorations, and continuous monitoring. These efforts aim to stabilize stream segments and significantly reduce sediment loading into the northeast quadrant of Mobile Bay. This is crucial for improving water quality and clarity, which is necessary for re-establishing submerged aquatic vegetation (SAV) beds that serve as critical nursery areas for shellfish and finfish (Ref 1). By using natural materials like rock and living plants, the project also seeks to create a sustainable and ecologically balanced watershed system (Ref 3).
The anticipated outcomes include enhanced water quality in D'Olive Creek and Mobile Bay, reduced erosion and sedimentation, and the restoration of vital habitats, which will contribute to the region's overall ecological health (Ref 1, 3). This restoration project is part of a broader strategy outlined in the 2002 Comprehensive Conservation Management Plan for the Mobile Bay Estuary (Ref 1).