The Seine, the River dedicated to Paris
Résumé
In France, the Seine River was already being used as a waterway some 6000 years ago. It has favored the development of Paris since the Romans founded the city as Lutetia. In the Middle Ages, the transportation of timber rafts and food supplies on the river, river mills, and direct use of the water supply sustained the growth of the capital city. New river uses were developed in the mid-19 th century: the river was gradually channelized and equipped with locks for navigation and received insufficiently treated urban wastewater. During the same period, the Seine riverscape was immortalized by impressionist painters. From 1870 to 1970, the river quality downstream of Paris continued to worsen in a context of urban development: few fish species survived, due to severe hypoxia in the Lower Seine, until a giant wastewater treatment plant, Seine-Aval, was constructed in the 1940s-1990s. This effort led to an improved basic environmental quality in the 1990s, which allowed the gradual restoration of fish populations downstream of Paris. The longitudinal and transversal connectivity of the river was again reduced after World War II: major reservoirs were built in the headwaters for flood control and sustaining low flows in the river reach within Paris, and the original floodplain wetlands were transformed into several hundred artificial sand pits. Today, migratory fishes are now gradually returning, including salmon in the lower part of the river, thanks to specific fishways which partially restore migration pathways. From 1960 to 2010, Parisians had very little contact with their river: fluvial navigation, flood control, sand extraction, river bank car traffic, and poor water quality were the limiting factors. The inscription of the banks of the Seine in Paris by UNESCO on the World Heritage list in 1991, signaled a reversed trend in the expectations of the riverside residents concerning their river. Associations and officials have since requested the ecological restoration of urban rivers, including the Seine, and the conservation of the few remaining natural wetlands. Recreational amenities were re-established from the 2000s onwards, and the swimming competitions, planned for the Paris Olympic Games in 2024, are a driver to reach a better bacteriological river quality. However, the Seine River, impacted by a metropole of seven million people and its related impacts, is set to remain a highly modified river, and will continue to be regulated to provide the economic functionalities and restored to provide the ecological functionalities expected today; coordinated governance at the scale of the whole river basin, successful in terms of water quality, has yet to be realized in other domains such as flood security or habitat restoration.
Domaines
Environnement et SociétéOrigine | Publication financée par une institution |
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