Scaling-up nature-based solutions for climate-resilient cities

Our future is urban. Cities fuel our economies, nurture innovation and have tremendous capacity to improve quality of life. More than half of the world’s population now live in urban areas—a figure that is set to increase to 68 percent by 2050 according to the UN. Particularly in developing country contexts, it is a major challenge for cities to provide the services that expanding populations need at a price they can sustainably afford.

The strategies and solutions that have served cities well in the past to address flooding, including conventional or ‘grey’ infrastructure approaches—e.g., dams and levees—may not be cost-effective or sufficient in the future as climate change exacerbates water hazards. Scaling-up and mainstreaming nature-based or ‘green’ solutions—e.g. constructed wetlands, raingardens and bioswales—underpinned by sound governance, private sector activation and genuine community engagement are important to create future communities in the Greater Mekong region that are sustainable, healthy and prosperous.

Through the Australian Water Partnership (AWP), the Australian Government’s Department of Foreign Affairs and Trade with the World Bank has been supporting an initiative to identify, evaluate and realise the benefits associated with Nature-based Solutions (NbS) for integrated urban flood management (IUFM) in the Mekong region. AWP partners, Water Sensitive Cities Australia (WSCA) and the International Centre for Environmental Management (ICEM) have been cooperating with government organisations in Thailand and Vietnam to demonstrate and build capacity on the use and economic valuation of NbS.

Regional perspectives

The AWP supported work included participation by 60 organisations from across six countries and resulted in the co-development of four demonstration of concept case studies, eight training events, a wide range of stakeholder meetings, and culminated in a successful regional conference with high-level policy and practitioner discussions, as well as in-depth discussions around practical application.

Around 200 conference attendees from government agencies and their partners in Vietnam, Thailand, Cambodia, Lao PDR and Australia joined policy and water experts on 24–25 November, 2021 to discuss how to move from proofs-of-concept and high-level support for NbS to implementing them at scale.

In their opening remarks for the conference, Dr Birgit Hansl, World Bank Country Manager for Thailand, and Ms Julia Feeney, Australian Deputy Head of Mission in Thailand, emphasised the importance of creating climate-resilient cities that can help improve the health, economic and social outcomes for the world’s most disadvantaged groups.

“Nature-based solutions can help address some of our most pressing societal challenges”, said Dr Birgit Hansl.

“The need for climate-resilient urban development is clear. Innovation and collaboration are essential to unlock opportunities that bring together nature, culture and sustainable economic development”, said Ms Julia Feeney.

Professor Tony Wong speaking at the Regional Conference

In his keynote address, Professor Tony Wong from Water Sensitive Cities Australia discussed how traditional approaches to urban design and water management have reduced the resilience of our cities to natural hazards, a vulnerability that is exacerbated by climate change.

“The battle for sustainability will be won or lost in cities”, said Professor Wong. “Urban renewal and investment give us an opportunity to reset how our cities operate”.

He provided examples of how hybrid systems can effectively merge conventional engineering with NbS. Including the application in cities to create an environment that will coexist with land-use change associated with urbanisation and urban development.

A high-level panel of senior government officials and policy-makers reflected on Professor Wong’s points and discussed the role of NbS in city transformations in Greater Mekong region countries. A panel of practitioners discussed some of the key factors to consider when implementing NbS. This set the scene for a more in-depth discussion on the second day on the pathways for implementing NbS in high-density cities and regional centres across Cambodia, Lao PDR, Thailand and Vietnam.

There was strong interest on building on the learning to date in Vietnam and Thailand to move from valuation to implementation of NbS as part of managing water, including flooding in urban areas. There was also interest from agencies in Lao PDR and Cambodia to uptake the approaches developed in the region and explore application as well as integration of NbS in planning and design in urban areas.

Demonstrating the benefits of NbS and hybrid solutions

The initiative has resulted in the co-development of four demonstration of concept case studies, two in high density city locations and two regional centres. The case studies in Vietnam and Thailand used IUFM as part of a collaborative process to identify, compare and fund portfolios of grey, green and community-based solutions that respond to local needs and opportunities. The case studies demonstrated the significant and quantifiable benefits of a hybrid approach using both green and grey or built infrastructure, as well as building the economic case for implementation.

Design of wetland conservation park in dry season, Phu Quoc, Vietnam (Source; Water Sensitive Cities Australia)

The cases highlighted the flexibility and scalability of NbS hybrid solutions and their potential to deliver value in diverse local contexts through:

  • Large NbS assets, such as parks, and smaller scale distributed assets, e.g., swales, tree pits, planter boxes, green roofs and walls, working together to form an integrated green precinct (e.g. Sukhumvit, Bangkok case study).
  • Networks of linear NbS assets integrated into urban roads and transport corridors, as well as retrofitting of grey areas such as car parks when large green spaces are limited (e.g. Rayong case study).
  • A catchment-scale perspective identifying upstream action for downstream urban benefits and lower overall costs (see Phu Quoc, Sukhumvit and HCMC case studies).
  • Water cycle solutions including flood responses that also create water supply sources and decentralised solutions for sewage and drainage management that improve both water quality and quantity outcomes (e.g. Phu Quoc case study).

Project leader, Ben Furmage also notes:

“The project also illustrated how a better understanding the distribution of costs and benefits of IUFM solutions can create opportunities for more inclusive outcomes as well as more informed, efficient, and fair decisions about who should pay, how and when.”

Australia is building on these cases and exploring opportunities within the Mekong to maintain momentum on NbS, such as creating a space for multi-disciplinary collaboration within and outside government to further accelerate and scale up nature-based innovations.

Feature photo: Benjakitti Forest Park, Thailand (credit: Sereechai Puttes / Time Out Bangkok)
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