High population growth and urban expansion pose a constant threat to the urban environment and exacerbate the risk of climate-related disasters. Several metropolitan areas in Indonesia exemplify these issues with significant consequences. The 2025 Greater Jakarta flood, which affected hundreds of thousands of residents, highlighted the recurring flood cycle of major floods, widespread impact, and acute vulnerability of urban areas to climate extremes, land subsidence, and inadequate infrastructure. Similarly, the Bandung Metropolitan Area experiences almost annual flooding, often localised due to basin topography and extensive upstream land conversion. 

Although the characteristics of these events differ, both cases underline the limitations of conventional grey infrastructure and its connectivity, which often fails under extreme conditions. In response, this policy brief examines Nature-based Solutions (NbS) as a sustainable and adaptive strategy to metropolitan flood management. By leveraging natural blue-green systems, such as wetlands, urban green spaces, and vegetated corridors, NbS offers both hydrological benefits and co-benefits, including improved biodiversity, urban cooling, and improved well-being. Lessons from Greater Jakarta and Greater Bandung highlight the urgency of integrating NbS into spatial planning and enhancing watershed management policies for metropolitan resilience.