Ecological restoration of ecosystems

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).

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).

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 Nyashishi wetland is located on the western side of Lake Victoria some 15 km from Mwanza, a port city of the lake. The area is characterized by a double maxima rainfall, with heavy rains occurring during October to December. The wetland is traversed by the Nyashishi River, which is an intermittent river draining stormy waters and domestic waste water into Lake Victoria. Increased human socio-economic activities in Mwanza, such as horticulture, overgrazing and discharge of industrial effluents, have degraded the Nyashishi wetland. As a result, vegetation specifically elephantiasis and papyrus that used to flourish in the wetland and provide fish breeding grounds have disappeared. The crocodiles, large lizards and a host of other creatures that used to populate those areas cannot be seen today. Since the wetland and the river are part of the Lake Victoria Basin, both have been subjected to floods and droughts, impacting livelihoods, public health and the environment. The root causes of floods are irregular seasonal and year to year variability in rainfall patterns, combined with mismanagement of land and water resources, leading to soil erosion and increased run-off. Therefore restoration efforts in the area are much needed. (1, 5)

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.

Taru Leading Edge initiated a lake conservation project in Indore with support from the Rockefeller Foundation and Indore Municipal Corporation as part of the Asian Cities Climate Change Resilience Network (ACCCRN).
Urbanisation and the increase of impermeable surfaces reduced the capacity for groundwater recharge. The climate change risks indicate increasing rainfall variability and more intense and/or more frequent storms as well as an increase in dry periods. With less permeable soils the city needs to optimally use existing lakes to capture runoff, creating buffer supplies and helping to increase groundwater recharge. The main objective of this project was “ensuring availability of local water resources during emergencies”, through developing a replicable model for peri-urban lake rejuvenation and conservation. The expected outcomes of the project include a stakeholder-managed process for stabilising/improving the water quality of the restored lakes and generating interest among multiple stakeholders to conserve urban lakes. TARU has restored and worked on 2 water bodies, demonstrating methods and processes required to revive lakes that have co-benefits of groundwater recharge, aesthetic enhancement of the area, cool microclimate and possible livelihood restoration. The names of the lakes restored are Khajrana talab and Lasudiya Mori talab. [2, 4]

The Recreio green corridor project, launched in 2012 by the Municipal Secretariat for the Environment and several city departments, aims to protect and enhance the rich biodiversity and ecosystems of the area, to help with the resilience and adaptation of the west side of the city, an area affected by coastal flooding and erosion. The project mostly focused on preserving, connecting, and expanding the existing local urban nature elements and protecting their ecology. Lastly, the project also aimed to educate the residents about native vegetation and help build social interaction and cohesion between the local communities [Ref 1]. The project was designed to preserve and connect 320.76 ha of protected areas and add 60.73 ha of open public spaces and squares. And in total, the corridor has a linear extension of close to 8 kilometers, passing through very diverse urban areas (Ref. 7), including natural parks, a lagoon system, water canals, and social housing areas.

Mexico City's (CDMX) Water Fund was established in 2015 by The Nature Conservancy Mexico on behalf of the Latin American Water Funds Partnership aiming to reduce the imbalance of the aquifers providing significant water supply for the territory of the CDMX and promoting positive long-term water balance (1). "The Water Fund emphasises good science in relation to the selection of sites and interventions, and in comprehensive monitoring. It seeks to make the business case demonstrating that these activities show returns with respect to water security" (1 p22). The first pilot project of the CDMX Water Fund engages small-scale producers in sustainable agriculture practices, works to restore and conserve water-absorbing land and reconvert land to water-friendly agriculture practices (1)

The Water Forest region covering around 250,000 hectares in the hinterland of Mexico City provides 70% of the city's urban water demand through the aquifers located below the forest. It consists of forest fragments and grasslands, encompasses four mountain ranges, and two adjacent Mexican states – Morelos and Mexico State with national parks (2). However, as native grasses are replaced by human settlements and poorly sited tree-planting projects, water available to recharge the aquifers declines and their loss contributes to flooding in densely populated urban areas downstream (1, 2). The Water Forest Initiative initiated by a non-governmental NGO aims to develop and implement "a regional conservation strategy to provide water and other ecosystem services to Mexico City (CDMX), Mexico State, and Morelos through the protection and rehabilitation of the Water Forest Area" (1 p6).