The Bassée floodplain is a large area in the Seine river basin (~ 50 km long and 5-10 km wide). Series of hydrological installations (dikes, channelization, damming, drainage, sand and gravel pits) have considerably reduced the flooding in the plain which nervertheless remains an important resource in the Seine river basin for freshwater and biodiversity. The level of anthropization increases from upstream to downstream. Projects for new hydrological installation (damming, channelization) still exist, which supports a high monitoring activity in this area.