Knowledge creation and awareness raising

The ROOF WATER-FARM is an innovative demonstration site located in the heart of Berlin, near Potsdamer Platz, showcasing sustainable urban infrastructure that integrates wastewater treatment and food production. Situated in the "Block 6" quarter of the 1987 International Building Exhibition in Berlin-Kreuzberg, the site transforms wastewater and rainwater collected from nearby buildings into usable resources for farming and fertilizer production (Ref. 1). This project provides a real-world example of how sustainable systems can be incorporated into everyday urban design to enhance resilience and functionality.

At the ROOF WATER-FARM, water from rooftops and surrounding households is channeled into a treatment plant, where it is analyzed for micropollutants and purified. The treated water is then used for both fish farming in aquaponics systems and plant irrigation in hydroponic farming. The nutrient-rich water from the fish tanks nourishes plants, while also contributing to the production of food. This integrated approach actively supports climate protection by managing rainwater runoff and using plants for CO2 storage, helping to mitigate the urban heat island effect (Ref. 4).

This demonstration site embodies how cities can move toward a circular economy, where wastewater is reused for both farming and water management. The project also serves as a hub for learning and experimentation in sustainable urban design, with the greenhouse acting as a space for collaboration and innovation in infrastructure development (Ref. 2; Ref. 5). By incorporating these technologies into urban environments, the ROOF WATER-FARM demonstrates a future where buildings and neighborhoods efficiently recycle water, produce food, and reduce environmental impact.

The "Line Park" project in Belgrade aims to create a continuous green belt spanning 4.6 kilometres and covering over 48 hectares. As such, the project will revitalize the former railway corridor from "Beton Hala", just below the Belgrade Fortress, to the Pancevac Bridge. Inspired by notable urban parks like New York's "High Line", Moscow's "Zagrađe," and Toronto's "Rail Corridor," it will become a major recreational destination and also help to alleviate the pressures from the city's heavy air pollution and summer heat (Ref. 5, 6).
The park will be divided into ten thematic sections dedicated to aromatic plant and flower gardens, urban gardening and beekeeping, sports facilities, a newly built university campus and more. Additionally, there will be an amphitheatre and facilities for outdoor education. To further integrate green infrastructure, new buildings will have green roofs and walls (Ref. 2,5). Ultimately, the park integrates a number of amenities into the entire city.
The development of the park also introduced innovative co-creation mechanisms in terms of governance and planning. Since Belgrade is part of the multinational CLEVER Cities Initiative, the city's Secretariat for Environmental Protection suggested the use of the site as a pilot test for introducing nature-based solutions in urban planning and with diverse stakeholders' input. Several workshops, focus groups, and consultations took place between 2019 and 2021, which facilitated the diversity of ideas that have been adopted into the official construction plan (Ref. 1, 2). Despite these successes, civil society groups raise concerns over the extraordinary cost of 70 million euros, displacement of Roma communities and the interest of real estate developers that may undermine the project's original cause (Ref. 3, 8).

According to the FAO, in 2022, 16.6 million Peruvians faced moderate or severe food insecurity, representing an increase of 1.5 million compared to the previous year (3). This situation was exacerbated by the health crisis, inflation, and job losses, leaving three out of ten Peruvians in poverty in 2021. The situation was particularly critical in Metropolitan Lima and Callao, with 14% of families reporting difficulties in acquiring protein-rich foods due to their precarious economic situation (2).
In response to this food crisis, the Municipality of Lima implemented the "Lima te Cuida" (Lima Takes Care of You) initiative, in which residents from vulnerable areas got training to create urban gardens and produce organic compost to help the community kitchens in these areas become self-sustainable (1, 2). An example of this initiative is the community garden in A.H. Villa Mosha in San Juan de Lurigancho, where a community garden has been built, and community members have been trained in small-scale planting, cultivation, care, and harvesting of various foods (2).
This initiative has been supported by the MUSA project "Mujeres Unidas por la Seguridad Alimentaria y Ambiental" (Women United for Food and Environmental Security) as part of the project "Alimentando a Lima desde Adentro" (ALDA) (Feeding Lima from within), which has had an impact in eight districts of Lima to strengthen food security (3). In addition to promoting urban agriculture, the project seeks to influence public policy through training and development of proposals to promote urban agriculture at the local level (4).

The GLAS Garden in Ballymun was established in 2011 by the NGO Global Action Plan, serving as a community-driven initiative that offers a welcoming and accessible space where people of all ages and abilities can engage with nature, learn new skills, and build connections within their community. The garden is actively utilized on a weekly basis by various groups, including St. Michael’s House, Saol Clubhouse, the Central Remedial Clinic, Ballark Youth Training, and Young Ballymun. It features a polytunnel for year-round growing, a whimsical fairy garden, and numerous microhabitats, including a pond, composting systems, a grow dome, and an innovative rainwater harvesting system made from recycled plastic bottles.
As part of the social regeneration program for Ballymun, the Green Living and Sustainability (GLAS) community garden has been operated by Global Action Plan (GAP) since its inception. It is supported by Dublin City Council under the Social Regeneration Fund and serves as a hub for environmental education and social inclusion in the area.
GAP’s GLAS garden brings together individuals of all ages and abilities, providing a socially inclusive space for participatory learning and active exploration of sustainability. It plays a crucial role in helping individuals and groups reduce their carbon footprint, produce organic food, and enjoy nature, thus transforming the garden into a space for positive change. (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).

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 Surco district of Lima has implemented a vertical bio-garden occupying a 685 square meter area within El Aire Park. The garden comprises a 600-meter linear structure supporting 11,000 planters fabricated from recycled plastic bottles. This system yields a substantial crop production of between 400 and 1,500 varieties on a 20-day cycle (1).
Initiated by the Municipality of Santiago de Surco, the bio-garden is designed to contribute to the district's economic, nutritional, and environmental sustainability (1, 2, 3, 5). By cultivating high-protein, nutrient-rich crops, the municipality provides essential sustenance to 24 local community kitchens (1), a local market (3), parishes, and social aid organizations (1).
To optimize crop yield, the municipality has implemented specialized techniques, including seedling cultivation, harvesting, and organic fertilization, to prevent pest and disease infestations (1). Since its implementation in 2020 with an initial 7,000 planters, the project has expanded by 300% to accommodate 11,000 (1). Cultivated plant varieties include medicinal herbs, leafy greens, root vegetables, and infusion ingredients (2, 5).
Additionally, the initiative serves as an educational platform, demonstrating and spreading sustainable home gardening practices utilising recycled materials such as plastic bottles (3, 5).

A community garden opened in 2023 on the Technological University (TU) Dublin Blanchardstown campus. This environmental education and social inclusion project is a collaborative effort involving Fingal County Council, Global Action Plan Ireland, TU Dublin, and the local community. It provides a space for local groups and schools to grow fresh produce, reconnect with nature, and foster a stronger sense of community.
Rooted in a successful template developed by Global Action Plan in Ballymun, this initiative promotes social and cultural inclusion alongside environmental education. The Green Living & Sustainability Community Garden (GLAS) aims to create an inclusive environment that welcomes individuals of all ages, abilities, and backgrounds. More than a site for cultivating plants, flowers, and vegetables, the garden serves as a hub for fostering social connections, enhancing well-being, and offering valuable educational opportunities.
The garden provides individuals with the chance to engage in social horticulture, exploring the connections between food, health, biodiversity, and global issues such as climate change. It operates on organic and regenerative principles, with all tasks and harvests shared by volunteers. Additionally, the garden will support youth gardening projects and public workshops on topics such as growing food, composting, water harvesting, and waste management. Beyond its environmental benefits, the garden helps people connect with one another, positively impacting social, physical, and mental well-being.

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).

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].