Waste management

Medellin is the second-largest city in Colombia. The city used to be one of the most dangerous in the world, as Pablo Escobar founded here the Medellin cartel. After the death of Escobar, the city's homicide rate has decreased by 95% and extreme poverty by 66%, thanks in part to a string of innovative mayors who laid out plans to integrate the poorest and most violent hillside neighbourhoods into the city centre in the valley below. The same innovative mayors realised that Columbia and its cities are very vulnerable to climate change being located in a tropical zone and is influenced by El Niño and the La Niña. In Medellin, the municipality has built upon a tradition of planning to become an urban lab for the construction of public life with the aim of inclusive, peaceful and sustainable development. As such starting in 2008 Medellin began implementing a green strategy whose goal was the creation of a green belt around the city as well as waste control. The intervention discussed in this case is one initiated in 2014 when the municipality carried out planting and reforestation projects for the protection of the eastern slopes of the city. (1,2,3)

Touted as a long-term solution to flooding of Mandaue City, establishment of a mangrove eco-park has begun, having received funding from the Department of Budget and Management (DBM) (Ref. 1). Through establishment of mangroves, the eco-park will "perform a significant role in shoreline protection, acting as a buffer against strong winds and waves", which is considered particularly important in light of the anticipated effects of climate change (Ref. 6).

A total 17-hectare plot is to be rehabilitated, as identified in the Mandaue City Government's Comprehensive Land Use Plan (Ref. 3). At present, it is unclear whether nature-based solutions (including mangrove restoration) are to be implemented across the entire 17ha of the site, but initial efforts have been focused on the restoration of a 5-ha section of mangrove forest (Ref. 2). Due to the lack of data on how exactly the remainder of the 17-ha area will be restored, the total NBS area for this project has only been recorded as 5-ha (5000m2) within this case study, rather than the entire 17,000m2 which is encompassed within the site.

The site is situated at the outfall of the Butuanon River which frequently overtops as a result of heavy rain and has been considered "biologically dead" since 1992 (Ref. 7). The site itself comprises a former dumpsite which had been "left derelict and filled with piles of trash", hence in addition to reducing flood risk, its rehabilitation will serve as green space in which "the residents of Mandaue City [can] gather and enjoy a breath of fresh air" (Ref. 2). The eco-park is considered to bring the added benefit of filtering water as it enters the Mactan Channel, in addition to reducing greenhouse gas emissions through carbon dioxide absorption (Refs. 1 & 6).

One of Valdivia's (in South Chile) southern peripheral neighbourhoods reaches the river of Angachilla which in time led to the creation of an urban wetland, a beautiful and large urban nature reserve of the city of Valdivia. The city of Valdivia is inserted in an extensive network of rivers and coastal wetlands, which penetrate the city through estuaries, hualves and meadows. The Angachilla estuary wetland is one of the most important, connecting the southern sector of the city with the Valdivia River estuary.
These urban wetlands provide important ecosystem functions that directly benefit citizens. Since 2007, the residents of Villa Claro de Luna (neighbourhood) together with various social organisations have worked on the recovery of the Angachilla Wetland, a natural space of great ecological and social value located in the city of Valdivia. Actions included carrying out cleaning, restoration and environmental education activities to recover a place that, abandoned and without any protection from the authorities, was converted into a clandestine garbage dump. (1,2,3)

The Krubong landfill site has been proposed to undergo a "thorough and safe environmental rehabilitation program[me]" so that the site can be developed as a public park (Ref. 1). Following completion of a feasibility study, it is envisaged that significant rehabilitation work to address environmental degradation and restoration of natural habitats will be required, after which the site will be developed into a public park (Ref. 1). The programme remains in its planning stage, but seeks to address Sustainable Development Goals (SGDs) 11.6 and 15.1 through protecting, restoring and promoting sustainable use of ecosystems and reversing land degradation and/or biodiversity loss; and reducing the environmental impact of cities by paying special attention to waste management and providing access to safe, open public spaces (Ref. 1). At a more local level, the programme intends to complement additional programmes laid out in Melaka's Resilience strategy document, including promoting both cycling and pedestrian networks and reshaping public spaces in the city (Ref. 1).

The Ecological Wetland Park is a 630,000 m2 artificial wetland located in a high tech industrial pioneer zone, adjacent to the Tianjin Harbor. The project was initiated by an agency of the local government and constructed with financial support from the Asian Development Bank (1). The area of the park used to be "a natural coastal salt marsh, which become reclaimed land in the early 2000s. The resulting saline-alkaline area had minimal ecosystem value and use value (as it was not considered to be suitable for agricultural activities either)" (1 p20). The wetland park's objective is threefold: 1) to provide a natural wastewater treatment plant for the industrial area to decrease pollutant discharge into the Bohai Bay and improve water quality; 2) to rehabilitating and restoring the once thriving biodiversity in the Harbor Area and the Hai river's estuary 3) to create a place for recreation and leisure for residents. (1)

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 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).

"Cape Town Environmental Education Trust (CTEET) is a non-profit environmental education organization that seeks to improve both the inclusiveness of urban nature reserves and the effectiveness of biodiversity conservation by connecting nearby disadvantaged and racialized communities with municipally-owned nature reserves." (1 p15) CTEET has 3 flagship projects: providing low-cost environmental education programs to children, offering training and development to Cape Town youth to access jobs in the Green Economy and supporting and driving conservation initiatives in Cape Town through its Nature Care Fund (2).

"The Urban forest strategy (UFS) is a central part of an innovative overarching policy framework of the City of Melbourne underpinning the city's aim to create healthy ecosystems for people and nature" in the period between 2012-2040 (1 p9). The UFS outlines a scientifically-vetted long-term process to re-nature the city with a diverse selection of urban trees and open space for and with the citizens, combining elements of an eco-managerial governance arrangement with an open and reflexive co-governance approach. (1 p11). The Strategy concentrates on 6 areas to achieve its goals: canopy cover, forest diversity, vegetation health, water quality and soil moisture, urban ecology and environmental stewardship among citizens. (1)

The Gorla Maggiore water park, inaugurated in March 2013, is situated within the municipality of Gorla Maggiore, in the Italian region Lombardy, located about 30 kilometers northwest of Milan. The water park is a constructed wetlands (CW) built on the banks of the Olona river that includes (a) a pollutant removal area composed of a grid, a sedimentation tank and four vertical sub-surface flow constructed wetlands; (b) a multipurpose area with a surface flow constructed wetland or pond with multiple roles; and (c) a recreational park with restored riparian trees, green open space, walking and cycling paths. [1]