Due to unsustainable land management and climate change, floods have become more frequent and severe over the past few decades and the problem is exacerbated in urban environments. In the context of climate-proofing cities, the importance of nature-based solutions (NBSs), obtaining relevant outcomes in the form of ecosystem services, has been highlighted. Although the role of ecosystem services in building resilience against negative climate change effects is widely recognized and there is an identified need to better integrate ecosystem services into urban planning and design, this has proven difficult to operationalize. A critical limitation is that modeling is a time-consuming and costly exercise. The purpose is to roughly estimate the ecosystem service of water run-off mitigation through simplified, cost-effective, and user-friendly modelling at three nested biophysical scales, under four climate change scenarios. Using the Swedish city of Gothenburg as an example, we propose an approach for navigating NBS-oriented flooding adaptation strategies, by quantifying the ecosystem service of water run-off mitigation at three nested biophysical scales, under four climate change scenarios, hence, proposing an approach for how to navigate nature-based solutions in a multi-scale, social–ecological urban planning context against present and future flooding events. Our findings validate the effectiveness of employing an ecosystem service approach to better comprehend the significant climate change issue of flooding through user-friendly and cost-efficient modeling.