The Gérine River restoration project aims to enhance its ecological functions and flood resilience by widening canalized sections. A two-dimensional numerical model using BASEMENT software was developed to simulate two design variations, each incorporating different widened channel layouts to encourage morphological development. The selected variant was further analysed for sensitivity to extreme flood events and varying sediment parameters. The simulations provided insights into preferential flow channels, erosion, and deposition areas, which are crucial for optimizing excavation work. The mass balance showed a net erosion pattern, consistent with similar projects in the region. These findings guide the restoration strategy while ensuring adequate flood protection even in case of extreme events.