Introduction Example of control for flood reduction (Rhine River): P.-J. van Overloop Example of control and data assimilation of dams and hydropower plants (Rhône River): P-O Malaterre, Nelly Jean-Baptiste, Christophe Dorée Example of quality control (algae) on the SCP and Gignac canal: Gilles Belaud, Ophélie Fovet Conclusion and perspectives