Situated in the Hindu-Kush Himalaya region, the world’s Third Pole, Nepal faces the harsh impacts of climate change with increased frequency and intensity of disasters. As Nepal’s cities expand—with 27 percent population living in urban areas and another 40 percent in peri-urban areas—hotter summers and monsoon-induced urban flooding are becoming lived realities.

Globally, urban areas are the centre of economic growth, innovation, access to services and decent jobs, and improved living standards. However, haphazard urbanisation exacerbates environmental degradation and social exclusion, stresses infrastructure and services, and accelerates the loss of ecosystems. This ultimately amplifies climate impacts, evident in Nepal through urban heat island effects, pollution, stressed urban water and drainage systems, urban floods and drought impacting the most vulnerable. With the accumulation of people, wealth and risks in urban areas, climate impacts are resulting in massive macroeconomic penalties. This convergence of urbanisation and climate crisis calls for a new generation of urban infrastructure.

For decades, cities in Nepal have relied on grey or hard infrastructure. The concrete-and-steel systems, such as roads, drains, flood walls and water supply networks, have formed the backbone of urban development and economic growth. These investments have been instrumental in connecting communities, expanding access to services and supporting businesses—driving Nepal’s broader social and economic transformation. Designed primarily to manage predictable conditions, grey infrastructure is increasingly challenged by extreme weather events. Amplified climate impact, meanwhile, demands that these infrastructures be resilient and support risk reduction.

Concurrently, the majority of local infrastructure investments focus on designs or solutions without considering their long-term environmental consequences. For instance, paving and concreting public and private open spaces for ease of construction and maintenance have severely reduced the potential of land to absorb rainwater. Water that once replenished groundwater now rushes directly into already overloaded drains, worsening urban floods while contributing to water shortages during the dry season. Even adding drainage pipes or widening the drainage channels cannot address increasing urban flooding if natural water infiltration systems are lost. Likewise, as expanding concrete and asphalt surfaces intensify urban heat, cooling through energy-intensive solutions impacts the local microclimate and deprives it of the multiple benefits of urban greenery and water bodies.

While historical settlements in Nepal were not designed for current climate risks, many evolved in ways that worked with local landscapes rather than against them. Floodplains were often left for agriculture, with settlements on relatively higher ground. Permeable paving materials allowed rainwater to recharge groundwater, while the buildings themselves moderated indoor temperatures through design, material and indigenous knowledge. These settlements integrated ponds, canals and other water bodies, and permeable open spaces that supported daily life, livelihood, social and religious rituals, while also cooling the neighbourhoods, preventing surface inundation and maintaining groundwater.

Of course, these approaches were not without limitations, but many embodied principles remain relevant today. In the fast-paced urban development, we may have overlooked the practices that could have been reinterpreted with modern engineering and technology. It is becoming more evident that combining the conventional ‘grey’ infrastructure with nature-based ‘green and blue’ solutions renders cities resilient, liveable and sustainable.

Cities across Asia are already demonstrating how this approach works. Singapore has integrated parks, rain gardens and blue-green corridors into its urban fabric. China’s Sponge City programme draws on centuries-old ecological wisdom of living with water to restore natural hydrological systems, reduce flooding, improve water quality and create more liveable urban environments. Today, cities around the world increasingly integrate nature-based solutions and ecosystem-based adaptations to complement the high performance of grey infrastructure with the adaptive and regenerative qualities of nature. Urban areas in Nepal could learn from our own history that creating a primary buffer to the grey infrastructure can absorb shocks and increase efficiency.

Encouragingly, this shift is emerging. Over the past decade, ecosystem-based adaptation has successfully restored forests, watersheds, wetlands and springs across rural landscapes in Nepal, protecting communities and livelihoods while reducing climate risks. As these risks are increasingly concentrated in towns and cities, the need of the time is bringing the same principles into urban development.

Current Urban Ecosystem-based Adaptation initiatives in Kathmandu Valley are demonstrating how nature can become an integral part of urban planning rather than an afterthought. By restoring urban ecosystems, improving green public spaces, managing stormwater through natural systems and embedding ecological thinking into municipal planning, these initiatives are showing that resilient cities can be built by combining grey and green infrastructure rather than choosing between them.

There is a growing public appreciation for greener urban spaces. Images of tree-lined streets, green river corridors, and jacaranda blossoms across Kathmandu Valley draw people outdoors—filling social media with vibrant colours. This reflects our innate affinity for nature and highlights people’s desire for more liveable cities. We must, however, recognise that ecosystem-based adaptation is not only about planting trees or creating parks. It is about redesigning cities so that natural systems help provide essential ecosystem services. It means reclaiming and reinterpreting green and grey spaces to reduce climate impacts and increase adaptive capacities. It is about treating nature not as a luxury, but as an essential urban infrastructure.

Beyond resilience, complementing urban grey infrastructure with blue-green infrastructure comes with multiple co-benefits. It helps make neighbourhoods cooler, improves air quality, supports biodiversity and provides spaces that support active and healthier lifestyles. Parks and rain gardens that retain stormwater during heavy rainfall not only reduce flood risks but also become places for recreation and connection with nature. By delivering flood management, cooling, recreation and public health benefits through a single investment, well-designed blue-green infrastructure also offers long-term value and lower maintenance costs.

The positive impact of blue-green interventions cannot be achieved only through technical demonstrations and isolated pilots. It depends on genuine participation, shared ownership and long-term stewardship of the communities to lead the whole of a society to imbibe and upscale the approach through household-level efforts. Further, nature-based solutions should be part of the infrastructure planning, designing and implementation process of the national and sub-national government, through enhanced technical capacity, adapted procurement processes and increased investments in collaboration with the private sector and IFIs.

The idea is to enhance grey infrastructure with management and restoration of ecological systems in our cities. Grey infrastructure provides function, while green infrastructure enhances resilience, quality of life and adds long-term value to the services. Nepal has the opportunity to upscale efforts, where engineering and nature work together for the people.