Nature-Based Solutions (NbS)

Nature-based Solutions (NbS) are defined by the International Union for Conservation of Nature (IUCN) as “actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits”. NbS are currently recognized as a design practice that has the potential to significantly increase the resilience of our infrastructures and buildings, often in a cost-efficient manner, helping cities and neighborhoods to adapt to and mitigate climate change impacts.

Green and blue infrastructure

Green and blue infrastructures are essential to re-establish the human-nature connection in urban environments, whilst providing infrastructural solutions that consume little or no energy, combat pollution and waste, and are not detrimental to the ecosystems to which they belong. On the contrary, they contribute to reconnect and restore the natural cycles of a specific place.

Urban environments specifically can no longer afford the luxury of single-purpose infrastructure. Practitioners must strive for a new infrastructure paradigm, designing for synergies between systems and, essentially, multi-functional networks that provide a range of services. This means opening to the possibility that our roofs can become gardens and energy collectors, and streets can be re-designed as multifunctional places for several public amenities and services, such as water collection and distribution, cycling routes, urban gardening and leisure green islands and parks.

Not only is the Quebradora park solution highly transferrable for regions where water flooding and water scarcity coexist, and in ecosystems highly affected by climate change consequences. It is also a perfect example of integration of a sustainable infrastructure with public spaces. Being public spaces largely influenced by government decisions, embedding sustainability in public spaces is a key strategy to scale up results.

Integrating urban utilities

Single-objective counter flooding infrastructure has turned hundreds of rivers into concrete channels around the world, losing ecological resilience and visual appeal. A project for a green-blue infrastructure network for the city of Shenzhen in China received a Holcim Awards Acknowledgement prize 2020 for Asia Pacific. The urban intervention integrates flood control, wastewater treatment and nature restoration. Using a biomimicry design that harnesses the biological processes of mangroves and wetlands, an old and inefficient cement drainage canal is transformed into a green and blue infrastructure that saves, cleans and distributes water.

Ecosystem restoration

The importance of ecosystem restoration on a global level is indicated by the UN Ecosystem Restoration Decade (2021-2030). The Holcim Awards Gold 2020 for Latin America was presented to Wetland Vitality in Bogotà, Colombia. Wetlands play an important role as carbon sinks, regulating carbon emissions by retaining 1/3 of the world terrestrial carbon. The landscaping planning of the project has recovered and consolidated a 157,000m2 wetland, through a 5.5km-long linear park that integrates recreational and natural areas and offers educational opportunities for the community. The selection of plants for the landscape is determined by each species’ impact on the ecosystem and ability to strengthen wetland flora and fauna.

Restoring biospheres

Larger green infrastructures can also be leveraged to promote biodiversity and compensate for urban deterioration. Restoring existing depleted habitats and soils is a key planning strategy to ensure removal of emissions from the atmosphere and provide stable and reliable carbon sinks.

Hanoi, the capital city of Vietnam, is among the most polluted cities in the world, with devastating effects on the environment and on the health of its citizens. Green Lungs Hanoi is a volunteer-initiated project that plans to restore subtropical forests on Banana Island, a 26-hectare parcel of land in the middle of Red River, in the attempt to bring more greenery into the urban area. Unlike public parks and botanical gardens, the project seeks to develop a self-sustained ecosystem through the reconstitution of the local flora and fauna and the promotion of biodiversity, in addition to addressing seasonal flooding and soil erosion. Propagated Sanctuary received the Global Holcim Awards Bronze 2021.

At the intersection of urban renewal, climate resilience and Integrated coastal zone management, the Bjarke Ingels Group (BIG)’s Dryline proposes a coastal infrastructure to protect Manhattan from flooding, integrating active flood gates and a 21Km large-scale flood protection system with landscaped areas and a range of neighborhood functions replacing dark parking lots and unused urban areas. Local opportunities, ranging from commercial, to recreational and cultural are enhanced by the planning. The Dryline project has been awarded the Holcim Foundation with a Silver Award 2014 for North America and a Bronze 2015 Global.