Due to major developments over the past two centuries, the Eau Morte Valley (a tributary of Annecy Lake) has a hydrosedimentary dysfunction with incised areas and areas with sediment excesses and an alluvial marsh disconnected from flooding. To reduce the impacts of the river's floods on uses, and to prevent the risk of urban areas flooding, a functional restoration programme for the valley has been developed by the federation of municipalities of Annecy lake sources. It was based on the renaturation of the Eau Morte bed, the functional restoration of the Giez marsh and the construction of crossing structures. This work has given the marsh a role as a flood expansion area. This project was also carried out by involving local residents in a process of territorial dialogue so that they themselves would be actors in the area and would participate in its management.