The Rance is a river of northwestern France. It is 103.6 km long. The semi-tidal river flows into the English Channel between Dinard and Saint-Malo. Before reaching the Channel, its waters are barred by a 750 metre long dam forming the Rance tidal power plant. The river is linked to the Vilaine by means of the Canal d'Ille-et-Rance. Départements and towns along the river:

Hydrology and water quality

Tributaries of the Rance include: This river has moderate turbidity and its brownish water is somewhat low in velocity due to the slight gradient of the watercourse; pH levels have been measured at 8.13 within the city of Dinan and electrical conductivity of the waters have tested at 33 micro-siemens per centimetre. At this reference location, summer flows are typically in the range of 500 cuft/s.