TheSeine (/seɪn,sɛn/sayn, sen,[1]French:[sɛn]ⓘ) is a 777-kilometre-long (483 mi)river in northernFrance.[2] Itsdrainage basin is in theParis Basin (a geological relative lowland) covering most of northern France.[3] It rises atSource-Seine, 30 kilometres (19 mi) northwest ofDijon in northeastern France in theLangres plateau, flowing throughParis and into theEnglish Channel atLe Havre (andHonfleur on the left bank).[4] It is navigable by ocean-going vessels as far asRouen, 120 kilometres (75 mi) from the sea. Over 60 percent of its length, as far asBurgundy, is negotiable by large barges and most tour boats, and nearly its whole length is available for recreational boating;excursion boats offer sightseeing tours of the river banks in the capital city, Paris.[5]
View over the Seine in Paris, Pont des Invalides in the foreground, Eiffel tower in the background
The Seine rises in thecommune ofSource-Seine, about 30 kilometres (19 mi) northwest ofDijon. The source has been owned by the city of Paris since 1864. A number of closely associated small ditches or depressions provide the source waters, with an artificialgrotto laid out to highlight and contain a deemed main source. The grotto includes a statue of a nymph, a dog, and a dragon. On the same site are the buried remains of aGallo-Roman temple. Small statues of thedea Sequana "Seine goddess" and otherex-votos found at the same place are now exhibited in the Dijon archaeological museum.[citation needed]
The Seine is dredged and ocean-going vessels can dock atRouen, 120 kilometres (75 mi) from the sea. Commercial craft (barges and push-tows) can use the river beginning atMarcilly-sur-Seine, 516 kilometres (321 mi) to its mouth.[7]
At Paris, there are 37 bridges.[8] The river is only 24 metres (79 ft) above sea level 446 kilometres (277 mi) from its mouth, making it slow flowing and thus easily navigable.[9]
The Seine Maritime, 123 kilometres (76 mi) from the English Channel atLe Havre to Rouen, is the only portion of the Seine used by ocean-going craft.[10] The tidal section of the Seine Maritime is followed by a canalized section (Basse Seine) with four large multiple locks until the mouth of theOise atConflans-Sainte-Honorine (170 km [110 mi]). Smaller locks atBougival and atSuresnes lift the vessels to the level of the river in Paris, where the junction with theCanal Saint-Martin is located. The distance from the mouth of the Oise is 72 km (45 mi).[11]
TheHaute Seine, from Paris toMontereau-Fault-Yonne, is 98 km (61 mi) long and has 8 locks.[12] AtCharenton-le-Pont is the mouth of theMarne. Upstream from Paris seven locks ensure navigation toSaint Mammès, where theLoing mouth is situated. Through an eighth lock the riverYonne is reached at Montereau-Fault-Yonne. From the mouth of the Yonne, larger ships can continue upstream toNogent-sur-Seine (48 km [30 mi], 7 locks).[13] From there on, the river is navigable only by small craft toMarcilly-sur-Seine (19 km [12 mi], 4 locks).[3] At Marcilly-sur-Seine the 19th centuryCanal de la Haute-Seine used to allow vessels to continue all the way toTroyes. This canal has been abandoned since 1957.[14]
The Seine's average depth in Paris today is approximately 9.5 meters (31 feet). Until locks were installed to raise the level in the 1800s, the river was much shallower within the city, and consisted of a small channel of continuous flow bordered by sandy banks (depicted in many illustrations of the period). Today the depth is tightly controlled and the entire width of the river between the built-up banks on either side is normally filled with water. The average flow of the river is very low, only a few cubic metres per second, but much higher flows are possible during periods of heavy runoff.
Four large storage reservoirs have been built since 1950 on the Seine as well as its tributaries Yonne, Marne, and Aube. These help in maintaining a constant level for the river through the city, but cannot prevent significant increases in river level during periods of extreme runoff. The dams areLac d’Orient,Lac des Settons,Lake Der-Chantecoq, and Auzon-Temple and Amance, respectively.[16]
Avery severe period of high water in January 1910 resulted in extensive flooding throughout the city of Paris. The Seine again rose to threatening levels in 1924, 1955, 1982, 1999–2000, June 2016, and January 2018.[17][18] After a first-level flood alert in 2003, about 100,000 works of art were moved out of Paris, the largest relocation of art sinceWorld War II. Much of the art in Paris is kept in underground storage rooms that would have been flooded.[19]
A 2002 report by the French government stated the worst-case Seine flood scenario would cost 10 billion euros and cut telephone service for a million Parisians, leaving 200,000 without electricity and 100,000 without gas.[20]
In January 2018 the Seine again flooded, reaching a flood level of 5.84 metres (19 ft 2 in) on 29 January.[21] An official warning was issued on 24 January that heavy rainfall was likely to cause the river to flood.[22] By 27 January, the river was rising.[23] The Deputy Mayor of ParisColombe Brossel warned that the heavy rain was caused byclimate change. She added that "We have to understand that climatic change is not a word, it's a reality."[24]
The basin area, including a part of Belgium, is 78,910 square kilometres (30,470 sq mi),[25] 2 percent of which is forest and 78 percent cultivated land. In addition to Paris, three other cities with a population over 100,000 are in the Seine watershed: Le Havre at the estuary, Rouen in the Seine valley andReims at the northern limit—with an annual urban growth rate of 0.2 percent.[25] The population density is 201 per square kilometer.
Due to concentrated levels of industry, agriculture and urban populations of Paris and its surroundings, the Seine-Normandy watershed experiences the highest human impacts of any hydrographic basin in France. Compared to most other large European rivers, the ability of the Seine to dilute urban sewage and farmland runoff is very low. Low oxygen levels, high concentrations of ammonia, nitrites and faecal bacteria, extending from Paris to the estuary, have been issues for over a century. The advent of nitrogenous fertilizers in the 1960s marked an upturn in agricultural pollution due to land use changes that had previously scaled with population growth. Heavy industries near Paris and along the Oise River discharged virtually untreated wastewaters from the turn of the 19th century, causing concentrations of toxins in the river that were ignored until the late 1980s. Major French laws to address water quality were passed in 1898, 1964, 1996, and 2006.[26]
At the beginning of the 20th century, most domestic sewage wasused as fertilizer for nearby croplands. As populations grew, the agricultural capacity to absorb those wastewaters was exceeded. Large-scale construction of waste water treatment plants (WWTPs) began in 1940 to meet demand; however, by 1970, about 60% of urban sewage was allowed to flow into the river untreated. The resulting oxygen depletion reduced the number of fish species to three. Measures taken in the early 2000s due to theWater Framework Directive led to significant reductions of organic carbon, phosphorus and ammonium, which in turn decreased the occurrence and severity of phytoplankton blooms. Continued WWTP construction and new treatment methods improved environmental conditions.[27] In 2009, it was announced thatAtlantic salmon had returned to the Seine.[28] By the early 2020s, the number of fish species near Paris had rebounded to 32.[27]
Periodically thesewage systems of Paris experience a failure known assanitary sewer overflow, often in periods of high rainfall. Under these conditions, untreated residential and industrialsewage is discharged into the Seine to preventbackflow. This is due in large part to Paris's "single system" drainage scheme dating from the 19th century, which combines street runoff and sewage.[29][30] The resultingoxygen deficit is principally caused byallochthonous bacteria larger than one micrometre in size. The specific activity of these sewage bacteria is typically three to four times greater than that of the autochthonous (background) bacterial population. Heavy metal concentrations in the Seine are relatively high.[31] The pH level of the Seine at Pont Neuf has been measured to be 8.46. Despite this, the water quality has improved significantly over what several historians at various times in the past called an "open sewer".[32]
In 1988, then-mayor of Paris and future presidentJacques Chirac first called for the lifting of a swimming ban that had been in place since 1923 due to polluted waters.[33] In 2018, a €1.4 billion ($1.55 billion) cleanup programme called the "Swimming Plan" was launched with the aim of making the river safe to use for the2024 Summer Olympics. The project included constructing a basin to store rainwater, which would then be slowly released into the sewer system, preventing overflow. Plans also call for several public swimming areas to be made available by 2025, bringing an end to a century-old ban.[34] These efforts have produced mixed results, asE. coli levels have often been found to be far higher than what is safe to swim in, though this could depend on the season.[35][36] At the same time, the fish population in the river has surged, from just two species to over 30.[36] To demonstrate the river's improved cleanliness, MayorAnne Hidalgo and PresidentEmmanuel Macron both pledged to take a swim in the waters,[37] and Hidalgo did so on July 17, 2024.[38]
During the Summer Olympics, the date of the triathlon was postponed due to water quality issues,[39] as the earlier rainstorm during the opening ceremony had driven some untreated rainwater back into the Seine.[40] However, the triathlon proceeded the following day, after testing found the water quality to be sufficient for swimming.[41]
In July 2025, the Seine was reopened for swimming after a ban lasting almost 100 years.[42]
The nameSeine comes from GaullishSēquana, from the CelticGallo-Roman goddess of the river, as offerings for her were found at the source. Sometimes it is incorrectly associated with Latinsequor 'follow', but the Celtic word rather seems to derive from the same root as Englishsea, namelyProto-Indo-European*seikw-, signifying 'to flow' or 'to pour forth'.[43]
On 28 or 29 March 845, an army ofVikings led by a chieftain named Reginherus, which is possibly another name forRagnar Lothbrok, sailed up the River Seine with siege towers andsacked Paris.
On 25 November 885, another Viking expedition led byRollo was sent up the River Seine toattack Paris again.
Following theburning ofJoan of Arc in 1431, her ashes were thrown into the Seine from the medieval stone Mathilde Bridge atRouen, though unsupported counter-claims persist.[45]
Plaque commemorating Robert Fulton's first successful trial of the steamboat in the Seine
On 9 August 1803,Robert Fulton, American painter and marine engineer, made his first successful test of hissteamboat in the Seine beside theTuileries Garden. Having a length of sixty-six feet and an eight-foot beam Fulton's steamboat attained speeds of three to four miles per hour against the Seine's current.[46]
Reaching the Seine was one of the original objectives ofOperation Overlord, during theSecond World War, in 1944. The Allies' intention was to reach the Seine by 90 days afterD-Day. That objective was met. An anticipated assault crossing of the river never materialized as German resistance in France crumbled by early September 1944. However, theFirst Canadian Army did encounter resistance immediately west of the Seine and fighting occurred in the Forêt de la Londe as Alliedtroops attempted to cut off the escape across the river of parts of the German 7th Army in the closing phases of theBattle of Normandy.
Some of the Algerian victims of the1961 Paris massacre drowned in the Seine after being thrown by French policemen from thePont Saint-Michel and other locations in Paris.[47]
More than a century later, during the2024 Summer Olympics, the Seine hosted a boat parade with boats for each national delegation during theopening ceremony.[50]
The river was also the site of the men's and women's event formarathon swimming, as well as the swimming portion of thetriathlon.[51] Although swimming in the Seine had been banned since 1923, a €1.4 billion cleanup effort by the French government sought to reduce bacterial levels in the river to those safe for swimming.[52] During the Olympics, daily tests of the water quality were taken to determine if it was safe for swimming; this caused the triathlon to be delayed by a day, before being allowed to proceed on July 31.[53] A few of the triathletes who swam in the river became sick afterwards,[54] though it was not clear if the Seine water was the cause.[55]
^Flipo, Nicolas; Lestel, Laurence; Labadie, Pierre; Meybeck, Michel; Garnier, Josette (2020). "Trajectories of the Seine River Basin".The Handbook of Environmental Chemistry. Cham: Springer International Publishing. pp. 1–28.doi:10.1007/698_2019_437.ISBN978-3-030-54259-7.ISSN1867-979X.
^abGarnier, J.; Marescaux, A.; Guillon, S.; Vilmin, L.; Rocher, V.; Billen, G.; Thieu, V.; Silvestre, M.; Passy, P.; Raimonet, M.; Groleau, A.; Théry, S.; Tallec, G.; Flipo, N. (2020). "Ecological Functioning of the Seine River: From Long-Term Modelling Approaches to High-Frequency Data Analysis".The Handbook of Environmental Chemistry. Cham: Springer International Publishing. pp. 189–216.doi:10.1007/698_2019_379.ISBN978-3-030-54259-7.ISSN1867-979X.
^Martin Seidl,The fate oforganic matter in river Seine after a combined sewer overflow, ENPC – University Paris Val de Marne Paris XII (France), 1997, 181 pp.
^A History of the Inquisition of the Middle Ages Vol. III by Henry Charles Lea, NY: Hamper & Bros, Franklin Sq. 1888, p. 325. Not in copyright.
^In February 2006 a team of forensic scientists announced the beginning of a six-month study to assess relics from a museum atChinon reputed to be the remains of Jeanne d'Arc. In 2007, the investigators reported their conclusion that the relics from Chinon came from an Egyptian mummy and a cat, seeButler, Declan (2007)."Joan of Arc's relics exposed as forgery".Nature.446 (7136): 593.Bibcode:2007Natur.446..593B.doi:10.1038/446593a.PMID17410145.
^Dickinson, Henry Winram (1913).Robert Fulton, Engineer and Artist: His Life and Works. London: John Lane Company. pp. 157–158.
.jpg)
