Improved stormwater management

Revitalizing Informal Settlements and their Environments (RISE) is one of the pilot projects carried out in the Batua neighbourhood (1.9 km2 area) of Makassar City (119 km2 area), province of South Sulawesi in Indonesia, which was commenced in 2017 and concluded in 2022 (1,2,3). Batua neighbourhood (six settlements of around 1,600 people) was the first demonstration site for this project which was completed in 2019 (3,4,5). The main challenge was that many households who lived in informal settlements lacked access to centralized urban infrastructure and faced threats from climate change (3,4). The project was proposed to reduce the impact of climate change on marginalized communities in Makassar by providing localized, water-sensitive interventions that addressed issues related to sanitation and water management (1,2,3,4). The introduction of water-sensitive solutions enabled targeted communities to recycle wastewater and rainwater, restore natural waterways, improve water quality, and reduce vulnerability to flooding (3,4). The RISE program initiative integrated nature-based solutions like wetland restoration, bio-filtration gardens (the process of using beneficial bacteria to clean water on a molecular level to remove contaminants), stormwater harvesting, filtration paths and new sanitation structures to improve wastewater management and diversify water resources through community-driven development (1,2,3,4).

The green roof development forms a 400-meter-long floating green ribbon above the SM North EDSA mall in Quezon City, Philippines. [3] It boasts a 15000m2 area filled with 55 species of native trees, bushes, and flowers that thrive in the local climate, and it relies on stored rainwater runoff to sustain its plant life. Visitors can access the mall via entrances located within the garden's openings and tunnels leading to shops and cafes nestled beneath the botanical landscape. A meandering pathway guides visitors through the space, which features various entertainment options. The garden provides a unique and innovative space for mall-goers and city dwellers to relax and interact with nature. [1,2]

The ‘City of 1,000 Tanks’ project offers a holistic solution to the problems of floods, water scarcity and pollution in Chennai (Ref. 1). The project's primary objective is to develop a "Water Balance Model" for the city, which involves collecting rainwater, treating wastewater and runoff pollution with decentralized nature-based solutions, as well as prevent climate-change-induced droughts and saline intrusion due to sea-level rise (Ref. 1, 2). This is achieved through developing various nature-based water management solutions and improving the recharge capacity of traditional temple tanks (Ref 1).
The project began in 2018, following the call for action event of the "Water as Leverage for Resilient Cities Asia" (a bilateral program spanning several Asian countries). The Water Balance Model is developed as a strategy with an incremental implementation process (Ref 1, 2). The project started with pilot projects and then progressed to flagship projects before full city-wide implementation (Ref. 3).

Spanning over 32000 square meters and featuring a landscaped rainwater catchment basin [5], the Rain Garden was created in 2014 in the Nuvali district of Santa Rosa. The garden offers an example of eco-friendly urban planning in the Philippines, as the Nuvali district is an eco-city itself with residential, business and commercial areas. Besides the Evozone Rain Garden, Nuvali also has various nature amenities, including a multi-functional lake, cycling and hiking paths, a wildlife and bird sanctuary and camping grounds. The Evozone Rain Garden was established in a commercial development area and it includes spacious open areas and cycling paths, along with the footbridge and view deck and adjacent to the manmade lake in Nuvali [2]. The Rain garden also serves as a rainwater catchment basin, rainwater harvesting system, and fire reserve, providing recycled water for landscaping, irrigation and other non-potable water uses [1]. In addition, the garden has been developed to serve as a habitat for various bamboo varieties and birds [4], also making the garden an ideal birdwatching spot [3]. The EvoZone Rain garden is free and open to the public [2].

Kempegowda International Airport Bengaluru (KIAB)'s new terminal 2 is an environmentally friendly initiative that uses innovative methods to maintain ecological sustainability using native plants (Ref 1, 2). The terminal was built on four guiding principles: technology leadership, being a terminal within a garden, environmental and ecological stewardship, and a celebration of Karnataka’s rich heritage and culture. Through the "terminal within a garden" project, the aim was to create a calming and relaxing space for passengers using greenery for visual appeal as people pass through the airport (Ref 1). Hanging gardens, trees, and green walls are the primary nature-related features included in the terminal and an outdoor greenbelt around the terminal. The airport uses native plant species, including trees, flowering plants, and shrubs (Ref. 2).
The terminal area also includes water bodies, cascades, and miniature waterfalls to maintain the natural atmosphere. The terminal also has extensive rainwater harvesting and groundwater recharge facilities (Ref 1). Other sustainable goals in the terminal area include energy saving, water conservation, waste management, and pollution control measures (Ref 2).

The Rajakori lake rejuvenation project aimed at reviving an existing lake using a natural and sustainable treatment system, the "Scientific Wetland with Active Biodigester (SWAB)". SWAB technology uses a two-step process involving (i) a sedimentation tank equipped with a biodigester and (ii) a constructed wetland system. The untreated sewage waste is passed through this two-step process that uses microbes and plants to reduce pollutant levels. The project also involved redeveloping the public space around the lake for community use (Ref 1,2). Before 2017, the lake was overfilled with sewage and waste from nearby neighbourhoods due to a lack of proper sewage management. Initiated by the Delhi Government, the project aimed at using low-cost natural methods rather than conventional techniques involving concretized bases and chemicals to treat water (Ref 1, 4). Due to its success and cost-effectiveness, this project now serves as an excellent example for other projects within Delhi (Ref 5).

In 2008, Mahidol University in Thailand announced its revised five-year Green Campus master plan titled 'A Promised Place to Live and Learn with Nature' for its main Salaya Campus. The scheme aimed to promote a green conscience and lifestyle for its students and faculty through sustainable campus developments that consider social and environmental aspects. The university's objectives were to achieve energy conservation, environmental sustainability, and social cohesion and well-being. The main features of the master plan included the creation and maintenance of green open spaces covering at least 70% of the campus premises, optimization of land use, transformation of infrastructure to encourage cycling, creation of outdoor learning, recreational and research areas, and enhancement of local biodiversity. The master plan also covered guidelines and targets for energy consumption, waste, and water management in the campus buildings. The Siri Ruckhachati Nature Park, the university's arboretum, was also redesigned with green and blue areas playing a role in flood management. Following the 'Green Campus' master plan, Mahidol University developed its existing mission further and became an 'Eco University' in 2012 and a 'Sustainable University' in 2021. These two missions focus primarily on reducing energy consumption and waste management.
(Ref.1,2,3,12)

The new office building of the Council of Engineers is located on one of the busiest streets of Bangkok, Thailand. The building aims to combine new engineering technology with aesthetic and function, while maximizing green area and promoting sustainability. The building's terraced green area lead the people up to the entrance on second floor and continue up to the sky garden on the forth floor. The main features of the garden are lush fauna with tree and shrub species, planters, multi-purpose open spaces and bio-filtration system that use plants to filter and divert rainwater. The project aims to acquire the platinum TREES building rating (a green building certificate in Thailand) and it is in the process of applying for the certificate. (Ref. 1,2,3,5)

The United Nations High Commissioner for Refugees (UNHCR) and its partners collaborated in 2018 to develop an ecosystem restoration project in the Rohingya Camps of Ukhiya, near Cox's Bazar. The main objective of this project was to mitigate the increased risk of landslides, slope instability, and flooding caused by flash floods and the vicinity of the Bakkhali River. The intervention included the planting of quickly growing native trees, shrubs, and grass species. Additionally, the project encompassed other measures such as vegetable cultivation on stream beds, biological soil stabilization methods, and plant-based wastewater treatments. To ensure the sustainability of the project, a network of future practitioners from the Bangladeshi and Rohingya communities was created. Moreover, environmental education and awareness activities were undertaken to complement the efforts of the project, with a particular focus on engaging young people from both the host and refugee communities to maximize its impact. The area where the project was implemented has been significantly affected by land and forest degradation over the last few decades, which has been exacerbated since the arrival of Rohingya refugees in 2017. Therefore, the project also involved other stakeholders such as the International Center for Conservation of Nature (IUCN), the Danish Refugee Council, the World Food Programme, the International Organization for Migration, and the Bangladesh government, each contributing in various capacities to achieve the project's objectives. (1,2,3,4)

The Bakhawan Eco-Park is a 220-hectare mangrove forest located in Kalibo, Aklan province, Philippines, that started as a reforestation project in 1990. It was a joint project of the local government and a non-government organization, Kalibo Save the Mangroves Association (KASAMA), with the aim of reforesting the muddy shoreline of New Buswang district to protect the community from floods and storm surges [1,2]. Aside from preventing floods, the eco-park also provides locals with livelihood opportunities, mitigates the effects of climate change, and serves as a habitat for various mangrove tree species, birds, and marine life [1,2]. The project's success is largely attributed to the active involvement and support of the local community, with some families playing an integral role in the reforestation program. [2] Notably, the involvement of local women in the NBS initiative has contributed to the success of mangrove conservation. Some women have also taken on the task of policing the mangroves to prevent illegal tree-cutting by trespassers [4]. Today, the eco-park is acknowledged as one of the most successful mangrove reforestation project in the Philippines [1]