Seine

The Seine is a major river in northern France, running about 775 kilometers from its source in the Burgundy region to the English Channel at Le Havre. Its drainage basin covers roughly 78,000 square kilometers. The river is a key waterway for both transport and culture, and its lower course is tidal.

From its origin, the Seine generally flows northwest, passing through or near several major centers. It defines a broad arc through the Île-de-France region, including Paris, before continuing to Rouen and then to the coast. The river’s watershed receives water from various tributaries, notably the Oise and the Yonne, with other smaller streams such as the Loing and Eure contributing to its flow.

Historically, the Seine has been an important route for commerce and movement of people. Paris grew and developed along its banks, while Rouen became a significant medieval port. Today the Seine remains navigable for commercial and passenger traffic, with a system of locks, dredging, and weirs that regulate depth and water level. The estuary near Le Havre is the tidal and maritime part of the river, where saltwater mixes with freshwater.

Environmental and management issues accompany its use. The Seine Basin faces challenges from urbanization, agriculture, and industry, but water quality improvements have been pursued since the mid-20th century. Flood control and river management are overseen by regional and national authorities to reduce risks and maintain navigation, habitat, and nutrient balance throughout the watershed.