Complex sentence: Its purpose is to maintain the system of flood-risk protection in the plains of the Isère, Drac, and Romanche rivers by preserving the integrity of embankment dams and their associated works.
Split into simpler sentences: Its purpose is to maintain the system of protection against the risk of flooding in the plains of the Isère, Drac, and Romanche rivers. This mission is carried out through interventions aiming to preserve the integrity of embankment dams and their associated works.