Climate change, changes in land use and urbanisation in the Lys and Yser cross-border areas have made municipalities increasingly vulnerable to the risk of floods. The LYSE project proposes integrated flood risk management through the implementation of cross-border actions such as the improvement of flood risk awareness, the installation of retention basins or the creation of soft hydraulic installations. The cross-border approach is essential on the topic of floods because rivers cross borders without regard for administrative boundaries. Solutions for resolving failures must be coordinated at the cross-border level to increase efficiency and avoid pushing problems downstream.