By Isabel Siew
A holistic approach to resilience
Across Asia-Pacific, cities are facing mounting pressures from rapid urbanisation, ageing infrastructure, climate change, flooding, drought, sea-level rise and water pollution. While the risks vary between locations, experts agree that water resilience requires long-term, integrated planning that brings together infrastructure, technology, nature, governance and communities.
For GHD executive advisor, Bharat Khanna, one of the biggest challenges is the mismatch between the pace of urbanisation and investment in essential infrastructure. With limited capital available, governments and utilities must prioritise spending and combine investment with technology and improved processes.
“Every water utility or client has a unique challenge,” Khanna said. “We need to understand that and focus on a consultative approach.”
Mark Fletcher, Arup’s global water business leader, similarly believes cities need to move beyond fragmented approaches. Many rapidly developing Asian cities face significant water risks but lack the long-term investment, strategic vision and technical capacity needed to respond effectively.
He advocates a “Total Design” approach that considers the catchment as a whole, bringing together engineers, hydrologists, ecologists, planners and digital specialists to develop integrated solutions.
Tony Wong, distinguished professor of sustainable development at Monash University, noted that resilience is not a one-size-fits-all concept. It depends on a city’s economic, environmental, social and institutional context.
Water resilience encompasses reliable water supplies during drought, the ability to withstand floods, water quality, biodiversity and urban liveability. Because these challenges often converge and compound one another, resilience requires an integrated approach. “Adaptability is fundamental to resilience,” Wong said, adding that communities must also be able to respond to uncertainty that cannot be addressed through infrastructure alone.
Combining infrastructure and nature
Traditional flood defences remain important, but experts increasingly see value in combining engineered infrastructure with nature-based solutions.
Ringo Mok, director of the Drainage Services Department of the Hong Kong Special Administrative Region, said flooding is not always a question of overall drainage capacity. During intense rainfall, leaves, silt and refuse can block drainage inlets and prevent runoff from entering the system.
“Relying on infrastructure expansion alone to eliminate flood risk in a dense and evolving city is not realistic and cost-effective,” Mok said.
Hong Kong has adopted an “Integrated Flood Management Strategy” based on an ARM approach — adaptation, resilience and management. This combines drainage upgrades with measures such as underground stormwater storage, demountable flood barriers, blue-green infrastructure, floodproofing and improved emergency preparedness.
The strategy also recognises that resilience is a shared responsibility involving contractors, utility providers, property managers, local authorities and communities.
Nature-based solutions can complement these measures, but Wong cautioned against viewing them as a replacement for conventional infrastructure. “The solution lies in our ability to integrate nature-based solutions with the more conventional engineering solutions,” he said.
By incorporating natural processes into urban planning and design, cities can manage stormwater while also supporting biodiversity, improving water quality and enhancing liveability. In Singapore, for example, Arup has worked on coastal protection planning that combines flood modelling and adaptive planning to assess how interventions could perform under future climate scenarios.
Harnessing digital technologies
Digital technologies are also changing how cities assess and manage water risks. According to Khanna, however, technology should be treated as an enabler rather than a solution in itself. “Digital transformation is the need of the hour. It is not optional anymore,” he said. “But technology is an enabler. It is not a solution.”
Successful digital transformation requires technology, people and processes to work together. Utilities must also avoid creating disconnected systems that cannot communicate with one another, he added.
Fletcher sees AI, predictive analytics and digital twins as tools that can help cities move from reactive to predictive management. In the Philippines, Arup supported the development of a proof-of-concept digital twin of the Pasig River, integrating hydrological, environmental and weather data to support long-term water management.
In Hong Kong, digital technologies are being used to improve flood monitoring and forecasting. The Drainage Services Department combines data from the Hong Kong Observatory, AI-powered CCTV analysis, more than 300 remote monitoring devices and over 110 flood monitoring devices.
Wong believes AI can also support community decision-making by allowing people to explore different scenarios and understand the potential outcomes of various choices. “AI actually provides a very sound technical basis to enable that community co-design, community decision making,” he said.
Planning for uncertainty
For coastal cities, climate adaptation is becoming increasingly complex as sea-level rise intersects with flooding, water security and urban development.
Wong highlighted the vulnerability of small island states, where rising sea levels can cause saltwater intrusion into groundwater supplies as well as coastal flooding and erosion. He argued that coastal protection should therefore consider freshwater security alongside flood protection.
The broader lesson is that resilience measures should deliver multiple benefits. Changes to seawalls and coastal infrastructure, for example, can alter local hydrology and must be accompanied by appropriate stormwater and water quality management.
Hong Kong is also taking a progressive adaptive approach to ageing infrastructure and evolving climate risks. With more than 370 facilities and over 4,700km of sewers and drains, its Drainage Services Department is using risk-based asset management, 3D scanning, building information modelling and AI-powered analytics to assess infrastructure conditions and prioritise upgrades.
Breaking down silos
Ultimately, building resilient cities requires collaboration between governments, utilities, industry, academia and communities.
Khanna believes governments must establish clear frameworks with defined responsibilities, milestones and measurable outcomes, while involving private-sector organisations and engineering firms in planning and delivery.
Fletcher similarly emphasises strong governance and shared objectives. Arup’s work on the Pasig River, for example, involved more than 40 government and community stakeholders, while its work under the Australia–India Water Security Initiative has supported urban water strategies across more than 4,700 cities.
Wong stressed the importance of breaking down institutional silos between water, infrastructure, environment and urban planning agencies. “The city is only one space,” he said. “If you actually introduce highly fragmented solutions to that city, it is very difficult to then undo that investment.”
Mok also highlighted the value of regional collaboration, with cities sharing data, methodologies and lessons from pilot projects to develop solutions suited to high-density coastal environments.
From resilience to action
Looking towards 2050, truly water-resilient cities will need more than stronger infrastructure. They will require integrated planning, adaptive systems, responsible use of technology, clear governance and active community participation.
Across the four perspectives, one message is clear: resilience cannot be built through a single project, technology or policy. It is an ongoing process of adapting to change, connecting systems and sharing responsibility. As cities across Asia-Pacific face increasingly uncertain water risks, collaboration and the ability to adapt may prove to be their most important lines of defence.
