Practitioners can’t agree on what Nature Based Solutions for flood management is: Why this matters and how to respond

Nature Based Solutions (NBS) is a practice based approach developed in response to the global challenge of on-going environmental degradation and biodiversity loss. Interventions that restore or mimic hydrological processes to slow water within a catchment come under an umbrella term of NBS for flood management. Proponents of the practice link its use as beneficial in reducing flood risk but also climate change adaptation, urban hazard management, sustainable agriculture and eco-hydrology. Despite promising an integrated and sustainable future and receiving policy support, catchment scale adoption is limited. Understanding, designing and delivering NBS flood management is complex, crossing multiple disciplinary divides and practitioner communities, each with its own history, background, methods and uncertainties. Barriers and intervention points within the delivery system has received little investigation from the view of environmental professional practice. This research addressed this gap through participatory case studies of projects delivering NBS in England. We found low agreement amongst practitioners on how NBS for flood management is distinguished, resulting in differing perspectives on its identity and contested boundaries between it and other land and water interventions. Our transdisciplinary research project sought and generated a context for delivery that breaks down disciplinary boundaries and in doing so a new system and intervention point emerged. The problem that practitioners used NBS for flood management to address is a homogenised water cycle: reduced infiltration and increased surface runoff. Therefore NBS for flood management aims to reverse this by restoring catchment hydrodiversity in harnessing hydrological processes for integrated sustainable urban and catchment management. The implications for academic thinking and land and water management practice created by the novel conceptualisation of a catchment possessing an attribute of hydrodiversity is far reaching. In relation to supporting NBS for flood management mainstream adoption: the conceptualisation draws together different land use systems and a shared goal to deliver catchment hydrodiversity emerges enabling coordinated flood management at multiple spatial scales and across professional practice and disciplinary groups.