The EPTB Seine Grands Lacs is a French local authority gathering Paris (providing half of financing) and the 3 surrounding departments (Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne).
Its two historical missions are:
• To limit the human and the economic consequences of flooding caused by the Seine and its tributaries overflowing (ie flood prevention);
• To support the low water levels in order to maintain sufficient flows of the Seine and its tributaries (ie low water maintenance).
Its new mission as an EPTB is to integrate river basin management in partnership with the government and the Seine-Normandie water agency.
To fulfill these objectives, EPTB Seine Grands Lacs manages 4 reservoir-dams located in derivation of the Seine, the Marne, the Aube and one on the Yonne, which are able to store 810 million m³ of water.