The banks of the Rhone and the Île de la Barthelasse are often subject to flooding during autumn and March. The publication "Floods in France since the 6th century until today – research and documentation" by Maurice Champion tells about a number of them (until 1862, the flood of 1856 was one of the largest, which destroyed part of the walls). They have never really stopped as shown by the floods in 1943–1944 and again on 23 January 1955 and remain important today – such as the floods of 2 December 2003. As a result, a new risk mapping has been developed.