The Canal du Midi (; ) is a long canal in Southern France (). Originally named the Canal Royal en Languedoc (Royal Canal in Languedoc) and renamed by French revolutionaries to Canal du Midi in 1789, the canal is considered one of the greatest construction works of the 17th century.Ultimately the project cost from 17 to 18 million livres which at the time made it the second largest construction in the country after Versailles.
The canal connects the Garonne to the Étang de Thau on the Mediterranean and, along with the long Canal de Garonne, forms the Canal des Deux Mers, joining the Atlantic to the Mediterranean.
Strictly speaking, "Canal du Midi" refers to the portion initially constructed from Toulouse to the Mediterranean – the Deux-Mers canal project aimed to link together several sections of navigable waterways to join the Mediterranean and the Atlantic: first the Canal du Midi, then the Garonne which was more or less navigable between Toulouse and Bordeaux, then the Garonne Lateral Canal built later, and finally the Gironde estuary after Bordeaux.
Jean-Baptiste Colbert authorized the start of work by royal edict in October 1666, with the aim of developing the wheat trade, under the supervision of Pierre-Paul Riquet, and construction lasted from 1666 to 1681, during the reign of Louis XIV. The Canal du Midi is one of the oldest canals of Europe still in operation (the prototype being the Briare Canal). The challenges in these works are closely related to the challenges of inland water transport today. The key challenge, raised by Pierre-Paul Riquet, was to convey water from the Montagne Noire (Black Mountains) to the Seuil de Naurouze, the highest point of the canal.
The Canal du Midi was inscribed as a UNESCO World Heritage Site in 1996, because of its outstanding engineering and artistic design, and it was designated as an International Historic Civil Engineering Landmark in 2016.
Introduction
Location and profile of the canal
The Canal du Midi is located in the south of France, in the departments of Hérault, Aude, and Haute-Garonne. It is long, starting in the west at Port de l'Embouchure, Toulouse and terminating in the east at Les Onglous, Marseillan, where the canal opens into the étang de Thau (between Agde and Sète).
The Canal du Midi is a summit-level canal, climbing from Toulouse on the Atlantic side over a distance of to the Seuil de Naurouze or summit level, where the feeder canal enters. The total rise is , and the summit level is at an altitude of . This difference in level down to the sea is covered over the remaining distance of from Naurouze to Les Onglous on the Étang de Thau.
The design canal depth is with a minimum of . The draft allowed is although regular users advise that even with boats will occasionally touch the bottom because of silt deposits in many places. The width on the surface is on average with variations between and . Finally, the width of the canal bed is .Michel Cotte, Canal du Midi, marvel of Europe, édition Belin Herscher, 2003, , p. 57
This longitudinal profile of the Canal du Midi shows it rising from Toulouse (1) to the Seuil de Naurouze (2), then dropping down to Castelnaudary (3), Carcassonne (4) and Trèbes (5). The canal continues to Béziers after passing through the Fonserannes Locks (6), then Agde (7), to finish at Sète on the étang de Thau (8).
The longest canal pound is between Argens Lock and the Fonserannes Locks, while the shortest canal pound is between the two Fresquel locks.René Gast, The Canal du Midi and the Canals from the Atlantic to the Mediterranean, éditions Ouest-France, 2000, , p. 22
Legal status For historical reasons, the Canal du Midi has a unique legal status, which was codified in 1956A. Homont, noted by the Conseil d'État, Ministry of Public Works and Transport c. Dame Boudet, 3 May 1963, Judicial Topics: administrative right, 1963, pp. 489-490. in the Public Code of waterways and inland navigation, then in the General code of the property of public persons. Under Article L. 2111-11 of the Code, public domain of the canal is determined by reference to the fief once granted to Pierre-Paul Riquet and limits were set by an official report in 1772. The staff quarters and warehouses, as well as the Lampy reservoir, were also added. Articles L. 2124-20 to L. 2124-25 set rules for maintenance of the canal, which is generally the responsibility of the public entity that owns it, with the participation of communes and, in some cases, waterside residents.
Under the Act of 27 November 1897, the State of France owns the Canal du Midi and its management is delegated to the public body Voies Navigables de France, attached to the Ministry of Transport.
History
Abandoned projects
The building of a canal was an old idea. Numerous and sometimes utopian projects were devised to build a canal between the Atlantic Ocean and the Mediterranean Sea. Leaders such as Augustus, Nero, Charlemagne, François I, Charles IX and Henry IV had dreamed of it,René Gast, The Canal du Midi and the navigable waterways from the Atlantic to the Mediterranean, éditions Ouest-France, 2000, , p. 11. as it is a true political and economic issue. King François I brought Leonardo da Vinci to France in 1516 and commissioned a survey of a route from the Garonne at Toulouse to the Aude at Carcassonne.
The construction of such a structure would save vessels (of trade but also the king's galleys) and goods from sailing around the Iberian Peninsula which could take a month to complete. At that time shipping was fraught with dangers such as piracy and the Barbary pirates.Franck Ferrand, The Great adventure of the Canal du Midi, transmitted in Au cœur de l'histoire on Europe 1, 29 May 2013
The most realistic projects were presented to the King in the 16th century. A first draft was presented by Nicolas Bachelier in 1539 to the Estates of LanguedocCanal du Midi, Structurae, consulted on 20 August 2007. then a second in 1598 by Pierre ReneauMichel Cotte, Canal du Midi, marvel of Europe, Paris:Belin, 2003, 191 pages, , p. 23. and finally a third project was proposed by Bernard Aribat de Béziers in 1617. Read online, Pierre-Paul Riquet Bonrepos (Baron de), History of the canal of Languedoc, Impr. de Crapelet, 1805, 398 pages, , p. 8, These projects were abandoned because they did not give enough thought to the water supply for the canal and provided a system of diversion of water from Pyrénées rivers too complex or impossible to implement. In 1650 another engineer also proposed to divert water from the Ariège to Cintegabelle to bring a non-navigable canal to Pech-David near Toulouse. Again, the question arose of how to carry water to the Seuil de Naurouze at a greater height than that of Toulouse. Read online, Pierre-Paul Riquet Bonrepos (Baron de), History of the canal of Languedoc, Impr. de Crapelet, 1805, 398 pages, , p. 9,
The projects were not launched for fear of losing too much money and conviction of the human impossibility to dig such a canal. The major problem was how to supply the summit sections with enough water.Chandra Mukerji, Impossible Engineering Princeton: Princeton University Press, 304 pages, Jean-Denis Bergasse Le Canal du Midi Cessenon: J-D Bergasse 1982-1984, .
Nevertheless, Pierre-Paul Riquet, a wealthy collector of salt tax in Languedoc proposed a more convincing project than his predecessors. When Louis XIV received his proposal through the Archbishop of Toulouse (Charles-François Anglure of Bourlemont) in 1662 he saw the opportunity to deprive Spain of part of its resources, and the opportunity to mark his reign with an imperishable work.
English translation:
Study of the project
Compared to canals, managing rivers is difficult but only one canal is required between the Atlantic Ocean and the Mediterranean Sea. Unlike a river, it is easier to manage the flow of a canal to ensure a constant flow of traffic throughout the year.
The Canal du Midi is a summit-level canal because it must pass over a height between two valleys. The construction of this canal required passage through the Seuil de Naurouze or the Seuil de Graissens.Michel Cotte, Canal du Midi, marvel of Europe, Paris: Belin, 2003, 191 pages, , p. 13.
Thirty years passed from the start of planning to the commencement of work: a similar project was also studied by a committee of which Riquet's father was a member.
Highlights In 1660, Riquet found the solution to the main problem: the water supply to the summit point to feed both sides of the canal. His idea was to get water flowing from the Montagne Noire. His important knowledge of the hydrography of the Montagne Noire and Sor allowed him to imagine an ingenious irrigation system.Michel Cotte, Canal du Midi, marvel of Europe, Paris:Belin, 2003, 191 pages, , pp. 24 & 27 citing the source: Brouillon du mémoire accompanying the Letter to Colbert, 28 November 1662, Archives of the Canal du Midi, VNF Toulouse, 1-7. He was inspired by the French engineer Adam de Craponne who had implemented the same system for the Craponne Canal.
For this, he planned to recover the mountain waters in dams and reservoirs and then forward them to the Seuil de Naurouze through channels crossing the Seuil de Graissens. The water from the Sor passing near Revel was the main supply envisaged by Riquet. Other rivers from the Montagne Noire were also part of the system such as the Alzeau, the Laudot, the Rieutort, the Bernassonne, and the .René Gast, The Canal du Midi and the navigable waterways from the Atlantic to the Mediterranean, p. 15. The Montagne Noire is a region with twice the rainfall of the plain of Lauragais with 1400 millimetres per year at around above sea level.Michel Cotte, Canal du Midi, marvel of Europe, Paris: Belin, 2003, 191 pages, , p. 24, how to recover a large quantity of water? To store the river water he planned to create three basins: the Reservoir of Lampy-Vieux, a hexagonal harbour basin at Naurouze, and the Bassin de Saint-Ferréol with a large earth dam across the mouth of the valley of the Laudot stream.
In 1664, during the study of the project, the Estates of Languedoc asked Riquet to put into practice his idea experimentally. He then built a test channel diverting water from the Sor to the Seuil de Naurouze. It was the Rigole de la plaine which he completed in 1665 and used to prove that it is possible to bring water to the highest points of the course of the canal.Michel Cotte, Canal du Midi, marvel of Europe, Paris: Belin, 2003, 191 pages, , p. 26. This was the event that reassured the Committee of Experts that the king had set up on site to inspect the choices and plans prepared by Riquet. From that moment Louis XIV knew that the canal was technically feasible. Read online, Pierre-Paul Riquet Bonrepos (Baron de), History of the canal of Languedoc, Impr. de Crapelet, 1805, 398 pages, p. 44
Inaccuracies by Pierre-Paul Riquet
Riquet studied in depth the supply of water to the canal at the Seuil de Naurouze. His study appeared rigorous and included a pilot phase with the construction of the Rigole de la plaine to substantiate his claim. The project still remained unclear in many respects especially the route of the canal. This route was not final and was not precise as it would be today for a highway project or high-speed railway. Only the directions of the route were known and plotted on a map. Changes in the route could be made by the Contractor depending on the difficulties he encountered on the ground. Read online, Pierre-Paul Riquet Bonrepos (Baron de), History of the canal of Languedoc, Impr. de Crapelet, 1805, 398 pages, , p. 50