By Laura Keil

From Pakistan to Kenya, Bangladesh to Brazil, floods have claimed hundreds of lives across the global south in recent months. Following the extreme flooding that hit Sri Lanka in June – displacing over 6,000 people, damaging more than 12,000 homes and resulting in 33 deaths – the need for a nature-based rethink of our cities is becoming ever more apparent. While monsoon rains are normal across Asia, flooding impacts are more severe and frequent due to climate change.

How can science support the lived reality of people? In an ideal world scientific research, design, and policy come together to find solutions that aid all life. Yet, they often remain disconnected in practice. Missing links between research, policy and implementation have resulted in cities that are unable to adapt to flooding.

Heavy monsoon showers inundated the roads in Dharga Town, Sri Lanka. Photo: Hafiz Issadeen.

Disconnect between research and policy

“We understand the urban flooding challenges currently faced by Colombo, and we can predict future challenges. Wetlands are one solution to urban flooding, so we must link the challenges and solutions by creating more recreational public spaces around wetlands. This is one of the most effective strategies, and it will only be accomplished through policy change,” opined Chethika Gunasiri, a postdoctoral researcher and sustainability professional.

Research often identifies effective flood management strategies, such as using wetlands and other ecological infrastructure, but these approaches are not always translated into policy. Environmental development regulations exist within Sri Lanka, but they are not strongly implemented or enforced in urban planning. Natural resource management is complicated and highly scattered, with many departments overseeing different wetlands and environmental assets.

“Urban transformation is possible by educating policy makers through multidisciplinary means,” shares Sunela Jayewardene, an environmental designer. Policies are often written behind the desk, without on-the-ground observation and interdisciplinary input. They do not always address the real-world complexities of urban flooding. Effective policy change requires integrating research insights into development. To permanently bring green infrastructure into cities, and protect existing urban nature, their benefits must be incorporated into policy.

Colombo wetlands. Photo: Martin Seemungal / IWMI.

Implementation challenges

In her role as an environmental scientist at the Sri Lanka Land Development Corporation (SLLDC), Gunasiri noticed that there is no proper connection between government agencies and research institutions. When doing flood and disaster control work, SLLDC occasionally partners with university students and researchers who are conducting related studies. But SLLDC is primarily an implementation organization and does not have the capacity to conduct their own research.

There is a gap between the scientific research on flood resilience and the practical implementation of these solutions. The work SLLDC is doing on wetlands, such as developing Gothatuwa wetland park, “should stem from scientific research,” says Gunasiri. She wants to collaborate with research-based agencies and donors to take the Beira Lake floating wetlands pilot project to a larger scale.

“Most efforts in the climate realm have been focused on capacity building, and although that is necessary, we also need to develop practical and specific measures and cases [that help communities]. This is where landscape architects come in,” says Ignacio Ortinez, a landscape architect based in Bangkok who has previously partnered with IWMI on green planning projects for flood control. He advocates for multidisciplinary teams because, “these projects are complex and interrelated among many professions.” The political, cultural, and natural aspects must be coordinated from the beginning. A lack of practical implementation of research findings exacerbates flooding problems.

Rendering showing restoration of Huay Mak Khaeng Canal in Udon Thani, Thailand. Photo/rendering: © UCRISP – estudioOCA 2018.

Funding obstacles

Constructing or restoring nature-based flood-prevention infrastructure such as wetlands, mangroves, and swales is 50% less expensive than traditional methods like concrete dykes. These natural solutions can provide equal or even better results in urban areas. Additionally, well-designed green infrastructure offers benefits beyond managing stormwater, including cooling, sequestering carbon dioxide, and enhancing tourism. “Wetlands have even more value than just flood mitigation,” shares Kasun Bandara, a civil engineer at SLLDC. He envisions the Colombo economy booming as a result of wetland eco-tourism.

Yet it remains difficult to secure funding for green infrastructure projects. Impactful urban transformation is possible by showing that these projects are, “science-based,” says Ortinez. There is a need for more evidence-based advocacy to demonstrate the value of these projects to potential funders. If unfamiliar with green infrastructure principles, it can be understandably difficult for city leaders to visualize the benefits. This is where scientific evidence comes in. Policies and green infrastructure implementation strategies do not become formalized without government backing.

Ortinez’s design studio estudioOCA melds landscape architecture with technical scientific elements for urban climate resilience. The studio work to create contextually sensitive projects that are developed in accordance with ecological principles and natural systems. The non-profit research wing of estudioOCA, Urban Climate Resilient Infrastructure & Strategic Planning (UCRISP), explores science-based and community-driven strategies for addressing climate change. Leading environmental design organizations such as the American Society of Landscape Architects (ASLA) support successful nature-based work in the United States. There is limited, if any, funding going towards similar projects in the global south despite these approaches needing to be more globally integrated. The funding gap must be addressed to ensure the implementation of green engineering structures, enabling the global north and south to tackle worsening flooding.

Research organizations that work almost exclusively in the global south, such as IWMI, have much to offer as they are already conducting nature-based research. IWMI, SLLDC and other project partners collaborated on the Increasing the resilience of biodiversity and livelihoods in Colombo’s wetlands project that finished in early 2024. The scientific research is happening, and now it is a matter of linking it with policy and implementation. Failure to effectively apply research findings worsens flooding impact.

Policy makers, built environment designers, and scientists must collaborate to bridge the gaps and address the largely untapped potential of melding water management and urban development in the global south. Collective and interdisciplinary action is urgently needed to improve existing and future infrastructure and urban development regulations in the face of climate change.

The Kelaniya River basin in Colombo was affected by major floods in 2016. Bandara shared that only 60% of the same area was impacted by identical rain patterns in 2024. He attributes this decrease to the measures SLLDC has taken to combat urban flooding, such as constructing a wetland park. Though individual flooding impacts may have lessened, the number of annual flooding events in Sri Lanka and globally is increasing. By protecting natural areas and funding the implementation of green infrastructure through coordinated research, policies and design, our public realm will become increasingly flood-resilient.

Benjakitti Forest Park in Bangkok. The park acts as a sponge during monsoon season and retains nearly 130,000 cubic meters of rainfall. The landscape also purifies contaminated water from the neighboring Phai Sing To canal. Photo: U-sah Pug.