Reframing natural in flood management

Natural Flood Management (NFM) has become a popular branch of research in contemporary flood risk management as policymakers and practitioners all around the world look for novel, holistic solutions to flood risk problems. As increasing river flows place additional pressure on conventional raised flood defenses, the upstream catchment offers opportunities to mitigate risk through flow attenuation and the potential for securing wider environmental and social benefits not typically associated with conventional flood defenses. The science underpinning these catchment-based approaches has advanced rapidly over the last two decades, and the terminology is now commonplace within policy and practice, but there has been little discussion around what “natural” actually means within the context of flood risk management. This paper explores the definition and framing of NFM within global anglophone scientific literature and industry guidance, to critically evaluate the robustness of the concept, both in theory and in practice. The analysis reveals a complex philosophical narrative and a physical implementation that does not always sit easily within an entirely “natural” framing. In order to advance the paradigm and ensure the long-term success of NFM as a mainstream approach to flood risk management, a case is made for moving away from the dichotomy of natural vs. engineered, through a reframing of these nature based, but not entirely “natural” solutions. A conceptualization of potential trade-offs between maximization of “natural” and optimization toward risk reduction is explored, which is of relevance to nature-based flood management initiatives gaining increased traction around the globe.