Adapting rivers to a changing world: Can restoration ‘reset’ riverscapes and increase resilience?

River management and restoration increasingly aim to create resilient rivers capable of adjusting to future environmental uncertainty. However, centuries of channel modification and floodplain disconnection have severely reduced river resilience. Valley-floor reset is a novel restoration approach that involves infilling existing channels and regrading the floodplain to re-establish hydrogeomorphic processes across the valley floor. By effectively resetting river–floodplain morphology, this approach is hypothesised to restore the capacity of rivers to evolve and adapt to changing input drivers. This study investigates the geomorphic and hydrologic responses of rivers to valley-floor reset restoration, focusing on the River Aller (UK), one of the first valley-floor reset restoration schemes implemented in Europe. Restoration transformed an incised, single-thread river into a wide, multi-thread river–wetland corridor by reconnecting channels to floodplains at low flows. Water storage increased by 1,156%, while the water table elevation rose across the valley floor by an average of 0.8 m. Subsequent geomorphic evolution has included channel development and sediment sorting, creating a mosaic of river and wetland habitats. The results demonstrate that reconnecting rivers to their floodplains at low flows can fundamentally alter the functioning of heavily modified rivers, shifting them from efficient linear drainage systems to laterally connected river-wetlandscapes, and offering a promising strategy for adapting rivers to a changing climate.