Firstly, module 1 of the RESI-project elaborates an analysis of ecosystem services provided by rivers and floodplains as well as the adapted methodologies and compulsory definitions. Afterwards, the different sectoral ecosystem services are investigated by considering several different management alternatives. Module 2 deals with the water and sediment balance as well as flood regulation. The transformation and retention of nutrients including the self-cleaning capacity of a river as well as carbon storage in floodplains is concerned in module 3. In module 4, the work is focused on the functions of rivers and floodplains as habitat for numerous endangered plant and animal species. Furthermore, the diverse resources of river corridors are quantified in module 5, such as timber, fishes or drinking water. In module 6, the cultural ecosystem services are evaluated regarding their potential and actual usage. After quantification, the ecosystem services are summarized and evaluated after standard proceedings, so that a final multi-criteria analysis can be performed in module 7 in order to build up the River Ecosystem Service Index (RESI). A practical test of the index is performed afterwards.