The Loire River, with 1 010 km, is the longest river in France. From its source in the Ardèche, it flows through the Massif Central to the Atlantic Ocean beyond the city of Nantes. Its watershed covers one-fifth of France (120 000 km2). The Loire is subject to heavy flooding and important seasonal fluctuations in volume. Spring floods alternate with dry summers causing very low water levels. Extreme high and low levels were recorded in December 1910 (6 300 m3/s) and August 1949 (49 m3/s). With such variability the use of the Loire for navigation is very limited. The river is called “the last wild river in Europe”.