Nature based Solutions and combined techniques in the immediate vicinity of infrastructure and residential areas - Case studies of steep bank stabilizations in the Garonne water catchment area in France realized between 1999 and 2022

Our motivation is to explain how severe bank slides, such as those following natural disasters, can be sustainably reintegrated into the river ecosystem in a modern, contemporary manner through the application of NbS and combined techniques. Our purpose is to explain the needs of an integrated engineering approach to find out the causes of streambank slides before works start. We point out the workflow of NbS reconstruction process by determining an efficient analysing stage, a construction stage and a monitoring stage. We show three realized examples of steep bank reintegration situated in high flow regime. Our conclusions show that reintegration into the river landscape of violent bank slides near residential areas and infrastructure with NbS techniques is feasible. The prerequisites, however, are a sufficient root cause analysis by an integrated engineering approach, and good training and experience of the hired construction companies during construction stage. In addition, clients need to throw out some of their old ideas of exclusively mineral and similar attachment techniques. This presentation serves as a demonstration of the potential of sustainable NbS steep bank revegetation for infrastructure protection, based on geotechnical analysis using examples realized in France between 1999 and 2022.