The Seine river experienced two major floods in 1910 and 1924, as well as a significant drought in 1921. The French government hence decided to find a solution to control the water levels. The lac d'Orient was filled with water in 1966, following six years long works. It covers 5,683 acres (2,300 ha) for a storage capacity of 208 million m3. Also a complex of ornithological interest, due to migrations or nesting, the lake is part of the regional natural park of the forêt d'Orient.