Waterways have had a major influence on history for thousands of years, as they facilitated traffic into the hearts of land masses. Gradually many great rivers have been linked by canals and improvements such as dredging and the installation of port facilities, on both small and major scales, have allowed the exploration, settlement and economic exploitation of huge areas of territory. The Seine has been a major factor in these areas. Rouen, despite being a full 75 miles inland, was Frances's premier seaport from the 16 to the 19th Centuries, only losing it's crown with the development of Le Havre. Even today, vessels with up to 3.2m draught can still ply from the English Channel to the Paris docks.
Further afield, the Marne connects to the waterways of the Rhine, allowing access into Germany, and the Oise feeds into the rivers and canals of Belgium.
The river not only provides
direct hydro-electric power, but the water from it is used as a coolant
for power stations, both conventional and thermo-nuclear. The water is
used for irrigation, industry, and as a source of drinking water for
both animals and humans.