Managing stormwater on urban surfaces with blue-green infrastructure (BGI) is being increasingly adopted as an alternative to conventional pipe-based stormwater management in cities. BGI combats water problems and provides multiple benefits for cities, including improved livability and enhanced biodiversity. The paper examines six municipality-led pilot projects from Beijing and Copenhagen, through a review of documents, site observations and interviews with project managers. Beijing’s projects attempt to divert from a pipe-based approach but are dominated by less BGI-based solutions; they could benefit from more integration of multiple benefits with stormwater management. Copenhagen’s projects combine stormwater management with amenity improvement, but lack focus on stormwater utilization. Reviewed municipality-led pilot projects are shown to play an important role in both testing new solutions and upscaling them in the process of developing more sustainable cities. Key lessons are extracted and a simple guideline synthesized. This guideline suggests necessary considerations for a holistic solution that combines stormwater management and urban space improvements. Key lessons for sustainable solutions include defining a clear water technique priority, targeting both small and big rain events, strengthening ‘vertical design’ and providing multiple benefits. An integrated stormwater management and landscape design process is a prerequisite to the meaningful implementation of these solutions. Research and documentation integrated with pilot projects will help upscale the practice at city scale.

Like numerous other cities, Beijing and Copenhagen are experiencing more frequent urban flooding due to increased impervious cover and climate change. Consequently, huge investments are foreseen to maintain resilience. Analyses of planning documents and interviews with key stakeholders reveal that in their climate resilience strategies both cities do employ alternative approaches based on on-site retention-detention of stormwater runoff. However, when there is an emergency situation with heavy downpours, both cities rely heavily on conventional concepts involving deep tunnels for rapid discharge. The applied alternative solutions tend to be more engineering-based, like underground tanks in Beijing and detention-discharge plazas in Copenhagen. More nature-based solutions lag behind. Both cities are simultaneously targeting specific additional sustainability goals. Nevertheless, other potential goals seem to be neglected, like livability improvements in Beijing and biodiversity support and water footprint reduction in Copenhagen. The main barriers for implementing more nature-based solutions with greater sustainability potentials were a combination of time constraints caused by external political pressures for rapid problem solving, lack of routines for the innovation and documentation of solutions for dense urban areas, and insufficient multi-sectorial collaboration. These factors limit the propagation of alternative solutions and tip the balance of current investments towards a conventional approach.