Bank re‐erosion action to promote sediment supply and channel diversification: Feedback from a restoration test on the Rhine

River regulation alters hydrological and sediment regimes consequently affects habitat complexity dynamics, biodiversity ecosystem services. Although channel bank erosion is a key geomorphological process supplying alluvial channels with coarse sediments diversifying aquatic riparian habitats, banks have often been stabilized to limit risk human activities facilities. The objective of this paper assess the effects, their sustainability, protection removal on 300-m long reach Old Rhine (France/Germany) promote supply, diversification rehabilitation fluvial morpho-sedimentary processes. This action was combined construction two island groynes locally increase Yearly detailed monitoring implemented over 6 years, including classical bathymetric surveys, airborne topo-bathymetric terrestrial LiDAR, bed grain-size bedload tracking. Following Q15 flood, restoration induced weak supply. diversified habitats due implementation groynes, inducing scouring creation new macroforms, as well local fining. cross-sectional diversity restored water close regularization engineering phase. Channel bedform persisted years persistence groynes. forms, in static manner, rather than processes, which raises questions about sustainability benefits such management actions terms functionality naturality.