Water management (SDG 6)

The Cheonggyecheon Stream Restoration Project saw the dismantling and removal of an elevated freeway and the uncovering of a 5.84km section of the Cheonggyecheon historic stream in the centre of Seoul, South Korea (Ref. 2). One of the world’s largest and most densely populated cities, the revitalisation of the Cheonggyecheon Stream has provided Seoul with an ecologically sensitive green pedestrian corridor in an area that was previously recognised as being congested, overpopulated and polluted (Ref. 4). The restoration has provided environmental, social and economic benefits within its immediate proximity (Ref. 2). In addition to becoming a "vehicle for revitalisation, urban renewal and economic development", it has "also signified a shift in Korean planning priorities", with both city authorities and residents now placing an emphasis "on health, sustainability and social responsibility" (Ref. 4). It has further "become a template for planning intention and action across South Korea" (Ref. 4).

The 'Step Garden' is a 14-tier green roof atop the Asian Cross Roads Over the Sea (ACROS) Fukuoka Prefectural International Hall in Fukuoka, Japan (Ref. 2). The Hall itself is a centre of international, cultural and information exchange, and sits amidst the Tenjin Central Park (Ref. 3). As the building displaced a plaza, the architect, Emilio Ambasz, created the “image of a mountain" through the design and installation of the roof terrace (Ref. 2), "want[ing] to give back to Fukuoka’s citizens all the land the building would subtract from the city" (Ref. 3). In combination with the Central Park, the rooftop garden is considered to be the only open green space in the city centre (Ref. 4), and since its inauguration in 1995, has been open to the public, accessible via two entrances on the park side of the building (Ref. 1).

A combination of green and grey coastal infrastructure is being developed off the coast of Semarang, Indonesia in response to the increased risk of coastal flooding as a result of sea-level rise (Ref. 1). Due to its geography as a coastal city, "Semarang deals with various physical challenges...such as tidal flooding, erosion, land subsidence and rising sea levels" (Ref. 1). Tidal flooding is becoming increasingly worse as a result of climate-induced sea-level rise and increasingly extreme weather events (Ref. 1 and 3). Coastal protection which was historically afforded by naturally occurring mangrove systems has been reduced as a result of the mangroves being largely lost to urbanisation, fish farming and other forms of agriculture (Ref. 2). One proposed sub-project of the Integrated Protective Coastal Zone, Coastal Balance Project 01: Coastal Balance Pilot in Genuk/Sayung, will focus on the northeast of Semarang. Using the 'Building with Nature' approach, it will leverage nature-based solutions through the deployment of green infrastructure, primarily focusing on mangrove restoration (Ref. 3). Mangrove restoration is hoped to stabilise the coastline, therein reducing erosion, encouraging sedimentation and increasing resilience against sea-level rise (Ref. 3).

Having been awarded the LEED Gold certification, the President Place building is considered the greenest building in the city. The building has been designed to create an exceptional balance between work, life and the environment. The 9th and 13th levels of the building have green roofs and terraces. President Place selected climate-tolerant plants that can survive on natural rainfall, and thus the green roof system does not require a permanent irrigation system. Effective practices were considered during the installation of the green roof, such as mulch for trees to conserve moisture, choosing plant species that can easily adapt to the site and need less irrigation. Trees have also been planted on the ground level. Additionally, the building is surrounded by permeable paving to help rainwater percolate easily. The aim was to create a visually appealing office building that leads the way in environmental, design-led construction in Saigon. [1, 2]

The Million Trees project was a programme launched by Auckland Mayor Phil Goff in 2017 to plant a million predominantly native trees and shrubs over a period of three years (Ref. 1,2,3,4). It aimed to make Auckland a greener, more beautiful place while creating carbon sinks, protecting the city’s waterways and improving the city’s living environment (Ref. 2,4). The programme engaged a variety of actors in the planting activities, including local boards, iwi, schools, service and social sector groups, private entities, the council group, the New Zealand Transport Association (Ref. 1). Particularly notable partnerships included those with the Department of Corrections and the Trees that Count Trust (Ref. 2,4,6).
The initial goal was met in 2019, and the project has been renewed for 2019-2022 (Ref. 1,7).

The revitalization and conservation of the Butuah Wetlands work started in 2020 by a Ghanian NGO, called Friends of the Nations, in collaboration with some public institutions and an American charitable foundation that makes small grants to grassroots environmental causes around the world. In the past, the wetland has been a major flood reservoir that channelled excess water from different parts of the metropolis into the sea as well as a beacon of biodiversity. The weak monitoring regime of this wetland has led to massive encroachments by both private and industrial developers, therefore, causing biodiversity depletion and contributing negatively to climate change. (1)

The wetlands to the east of Kolkata are well known over the world for their multiple uses. The locals are using the naturally occurring wetlands for wastewater fisheries and vegetable farming on garbage substrate & effluent irrigated paddy cultivation. In the process, the wetlands treat the wastewater and have saved the city of Calcutta from constructing and maintaining a wastewater treatment plant. Currently, encroachment has deteriorated the wetland ecosystem significantly. This intervention is about the management of the degraded wetland to recover it the best way possible. The goal of management planning is to „maintain East Kolkata Wetlands in a healthy condition to enable the delivery of its full range of ecosystem services and sustain biological diversity values’. [1, 2, 3]

The Green Urban Infrastructure in the municipality of Beira project aims to increase Beira’s resilience to climate change and flooding (Ref. 2). It is a two-part project that consists of rehabilitating the Chiveve River and constructing a public park along the river (Ref. 1). The river rehabilitation was completed at the end of 2016 and restored the natural flow of the river, enabling better flood control (Ref. 5,6). The public park was completed at the end of 2020 and serves as a recreation, catchment and overflow area through three basins of the river (Ref. 1,2).

The city of San Salvador was built at the foot of a volcano and down its slopes, it is prone to droughts, floods and landslides. In 2020, Tropical Storms Amanda and Cristobal struck the city with torrential rainfall and gale-force winds triggering landslides and floods, causing damage to homes, infrastructure and roads, and with severe impacts on topsoil depletion affecting the fertility of economically and environmentally central coffee plantations[3].
To meet the economic and environmental challenges caused by such events, the United Nations Environment Programme (UNEP) together with El Salvador’s Ministry of Environment and Natural Resources, local organizations and coffee growers launched an project focusing on the Arenal Monserrat watershed located on the slopes of the volcano [3,4]. Through the integration of Ecosystem-based Adaptation (EbA) the initiative aim to address the effects of climate change by restoring coffee plantations and forests and digging infiltration ditches to be used as sponges to reduce flood risks for 115,000 people by 2022 [1,4,5]. The project was launched as part of the multi-city CityAdapt Project of UNEP and GEF, aiming to provide tools to local governments plan for adaptation and mitigate greenhouse gas emissions from their cities while conserving their ecosystems.

The green roof pilot project is part of eThekwini Municipality's Climate Protection Programme, initiated in 2004, it was focused initially on understanding the vulnerability of the city of Durban to the impacts of climate change. A strong emphasis has been placed on identifying climate change adaption projects that will improve the resilience of the city to future developmental, social and environmental challenges. Basically, the green roof pilot project is a response to the higher temperatures and increase in the frequency and severity of floods and droughts that are expected as a result of climate change. From an urban environment perspective, these changes will exacerbate the already high temperatures experienced as a result of the Urban Heat Island effect and the high levels of surface run-off and flooding that result from the hardening of permeable surfaces. (1,3)