Abandoned projects , the designer of the Canal du Midi 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, 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. 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 Languedoc then a second in 1598 by Pierre Reneau and finally a third project was proposed by Bernard Aribat de Béziers in 1617. 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. 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. 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. 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. He was inspired by the French engineer
Adam de Craponne who had implemented the same system for the
Craponne Canal. at the
Seuil de Naurouze at the highest point with 189m altitude 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 . 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. 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. 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.
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. On the Atlantic side, he proposed several layouts: one to pass by
Castres and
Revel through the Seuil de Graissens and
Agout. In fact, this river was already under development for navigation. Another route would pass by the Girou river and avoid
Toulouse as in the preceding route. On the Mediterranean side, the route was not set. He would use the Fresquel until the
Aude but the arrival on the coast was first intended to be at
Narbonne then at
Sète. In 1663 Riquet conducted field studies to finally fix the path on the Atlantic side by the seuil de Naurouze along the valley of the
Hers-Vif to
Toulouse downstream of the
Garonne. The navigable part of the river is downstream of
Bazacle which was a ford in the centre of Toulouse, blocking navigation. The canal could not consider not going through the economic heart of the region so therefore the final route was via Castres and the Girou.
Study techniques Pierre-Paul Riquet had no technical training and learnt on the job. He regularly practised experiments and field observations. His technique remained highly empirical because at that time applied science and hydraulic techniques through laws or concepts had not been mastered. Even so, Riquet had a scientific approach as he systematically took measurements of
flow and made calculations of volumes. In addition, to overcome his technical shortcomings, he was surrounded by many technicians such as Hector Boutheroüe,
François Andreossy surveyor and cartographer, and
Pierre Campmas an expert in water flows. He set up experiments to prove that it was possible to bring the water to the
Seuil de Naurouze from the river Sor in the
Montagne Noire. He also built on his property in
Bonrepos a model of the canal with
locks,
tunnels, and
épanchoirs (spillways) reproducing the slopes and feeding all with water.
Political and economic context The economic situation of the country was quite difficult at the time. When
Colbert became minister he believed that domestic and international trade was not in favour of the
Kingdom of France. The
Dutch could take better advantage of trade and economic activity in the country. The prices of
grain dropped a lot and wine production fell in 1660. This crisis caused depreciation of land values and small farms were going bankrupt. In addition, the region of
Languedoc experienced religious conflict during the
Fronde. It was difficult to implement a policy in this area and in particular to introduce taxes such as the
salt tax. Colbert then saw Pierre-Paul Riquet and his project as a way to pursue a policy of economic expansion in the service of
absolutism in Languedoc. In fact, Riquet proposed himself to implement the salt tax and to build the Canal du Midi. Thus, the construction of the canal would permit the creation of a direct passage between the Mediterranean Sea and the Atlantic without passing through the
Strait of Gibraltar controlled by the Spaniards, the aim being to destroy the Spanish trade and establish a commercial flow through Languedoc. The Languedoc region had many resources such as
wheat,
wine from
Minervois,
woollen cloth,
silk, and
salt which producers were struggling to export due to lack of trade. By passing through the Canal du Midi, Colbert hoped to distribute goods in the different regions of
le Midi to strengthen royal power and open up Toulouse and its region.
The edict of Louis XIV and the financing of the project Despite a project that seemed precarious, Colbert authorized commencement of work by a royal edict in October 1666 after the approval of a committee of experts that looked at the route of the canal for several months. The project benefited significantly from the appointment of an engineer for fortifications and hydraulics –
Louis Nicolas de Clerville – who used his influence with Colbert to start the project. The decree specified the authorization of the construction of the canal, its issuing of
invitations to tender, and its awarding to the designer, Pierre-Paul Riquet, and his descendants. It also gave rights of expropriation to Riquet and describes the possibility of creating mills, warehouses and housing for the operation of the canal. The project formed a tax-exempt "fief" whose owner had the rights of
fishing and
hunting. Finally, it describes the operating procedures including the introduction of tolls, traffic organization, and ownership of vessels. The king decided to cede the ownership and operation of the facility in a particular order to overcome the potential drawbacks of a work so great. This system ensured the continued maintenance and operation of the canal even if the state's finances are at their lowest. The work was launched in two phases each called an "enterprise". The first enterprise of connecting Toulouse to
Trèbes was estimated at 3.6 million
livres. The finances of the State, however, were not very sound and the
Estates of Languedoc were not willing to fund such a project for fear that their funds would be used for unexpected expenses. So, in exchange for the ownership and operation of the canal, Pierre-Paul Riquet proposed to finance part of the works from his own funds. The rest was to be paid by the State in exchange for profits that Riquet earned from the salt tax. The second enterprise of works between Trèbes and the
étang de Thau in December 1668 cost 5.832 million
livres plus a million more livres for the resumption of work on the port of Sète. Ultimately, while the initial budget was six million livres, all the work together would cost between 17 and 18 million livres of the time, 40% was advanced by the King, 40% by the province, and 20% by Riquet himself, who became the owner. His descendants continued to pay two million livres for over 50 years.
Construction of the canal At the age of 63, Riquet started his great enterprise, sending his personal engineer,
François Andreossy, and a local water expert, Pierre Roux, to the
Montagne Noire to work on the water supply. This supply system successfully fed the canal with water where it crossed the continental divide, replacing water that drained toward the two seas. The system was a masterpiece of both
hydraulic and
structural engineering, and served as an early ratification of Riquet's vision. It was also a major part of the massive undertaking. Work began on the first "enterprise" on 1 January 1667 with the construction of the trough of the
Rigole de la plaine then continued on 15 April 1667 with the laying of the first stone of the
Lac de Saint-Ferréol. Originally Riquet wanted to build a dozen reservoirs but the Commissioner General of fortifications,
Louis Nicolas de Clerville, asked him to replace them with a single reservoir. This was a great novelty at the time – no reservoir-lake of this magnitude had ever been built before. Some of
Clerville's men with experience in military engineering came, to build the huge dam for the single reservoir, the
Bassin de St. Ferréol, on the river Laudot. The Laudot is a tributary of the
Tarn in the Montagne Noire some from the summit of the proposed canal at
Seuil de Naurouze. This massive dam, long, above the riverbed and thick at its base was the largest work of
civil engineering in Europe and only the second major dam to be built in Europe, after one in
Alicante in Spain. It was connected to the Canal du Midi by a contoured channel over long, wide with a base width of . It was eventually equipped with 14 locks in order to bring building materials for the canal down from the mountains and to create a new port for the mountain town of
Revel. In November 1667 an official ceremony laid the foundation stone of the Garonne lock in Toulouse in the presence of representatives of the
Parlement of Toulouse, the
Capitouls (sheriffs), and the
Archbishop of Toulouse, Charles-François d'Anglure de Bourlemont. A first filling of water was made between the seuil de Naurouze and Toulouse during the winter of 1671–1672 and the first boat traffic could begin. In 1673 the section from Naurouze to Trèbes was completed marking the end of the first "enterprise". From 1671 the second enterprise began linking
Trèbes to the
Mediterranean Sea and to build the port of
Sète (then called
Cette, the location was chosen and the port constructed by Clerville). This part of the canal posed problems at the junction between the
étang de Thau and Trèbes because the canal must cross the course of the
Hérault and the Libron. To work around the problem, Riquet set up a system of valves and chambers for Libron and a round lock with three doors for the
étang de Thau and the
Hérault. The round lock at
Agde could switch between a reach of the Canal du Midi and the Hérault. This part of the canal was also a problem at the level of the seuil of Ensérune and the descent to
Beziers in the valley of the
Orb. Riquet solved these problems on the one hand by digging the
Malpas Tunnel and secondly by building at Fonserannes a row of
eight lock chambers to the Orb. The
Malpas Tunnel was the first canal passage ever built through a tunnel. The Canal du Midi passes through a tunnel through a hill at the
Oppidum d'Ensérune. In 1681 work on the canal ended at Béziers. However, in October 1680, Riquet died during construction. He did not see the end of the project. It was the king's engineer,
La Feuille, who took over. His sons inherited the canal, but the family's investments were not recovered and debts not fully paid until over 100 years later. The canal was well managed and run as a paternalistic enterprise until the
revolution. The canal was built on a grand scale, with oval shaped locks long, wide at the gates and wide in the middle. This design was intended to resist the collapse of the walls that happened early in the project. The oval locks used the strength of the arch against the inward pressure of the surrounding soil that had destabilized the early locks with straight walls. The canal was opened to traffic in May 1683 and stopped receiving public works in March 1685.
Work organization and social conditions For fifteen years nearly 12,000 workers worked on the construction of the canal. Riquet hired men and women between 20 and 50 years old whom he organized in sections forming workshops led by a controller-general. This
rationalization of work permitted the optimisation of tasks and allowed several projects to be performed at the same time. All of the work was manual and the digging of the canal was with
shovels and
pickaxes. The workforce was made up of farmers and local workers whose number varied from one period to another during the year. Pierre-Paul Riquet appealed to the military to compensate for this fluctuation. He also set up monthly payments of workers for their loyalty. The women labourers were surprisingly important to the canal's engineering. Many came from former
Roman bath colonies in the
Pyrenees, where elements of classical hydraulics had been maintained as a living tradition. They were employed at first to move earth to the dam at Saint Ferréol, but their supervisors, who were struggling to design the channels from the dam to the canal, recognized their expertise. Engineering in this period was mainly focused on fortress construction, and hydraulics was concerned mostly with mining and problems of drainage. Building a navigational canal across the continent was well beyond the formal knowledge of the military engineers expected to supervise it, but the peasant women who were carriers of classical hydraulic methods added to the repertoire of available techniques. They not only perfected the water supply system for the canal but also threaded the waterway through the mountains near Béziers, using few locks, and built the eight-lock staircase at Fonserannes.
Trades and work measures implemented Many trades were found on the work sites of the canal in addition to the seasonal workers who were most often farmers. The
masons and
stonecutters were responsible for the construction of structures such as
bridges,
locks, and
spillways. The
blacksmiths and levellers were responsible for the maintenance of the tools and equipment. Carters and carriers, the
Farriers and owners of
sawmills were also requisitioned for the works. Workers were organized into sections controlled by captains and sergeants. Finally, Pierre-Paul Riquet was surrounded by aides as well as auditor-generals and inspector-generals of the canal. The workers' tools were very limited: picks, hoes and shovels to dig, baskets and stretchers to transport materials. They were provided to workers who must maintain them themselves.
Gunpowder was used to blast the rocks.
Inauguration In 1681 the first inspection took place "dry". The king appointed a commission composed of Henri d'Aguessau, steward of Languedoc, Mr de la Feuille, Father Mourgues a Jesuit professor of
rhetoric and mathematics at the
University of Toulouse, two sons and two in-laws of Pierre-Paul Riquet, as well as Messrs.
Andréossy, Gilade, and Contigny. This commission embarked for Beziers on 2 May 1681 and went up the canal back to Toulouse over six days. The filling with water had been done showing a measure of the progress of checks to Castelnaudary (the section Toulouse-Castelnaudary had water since 1672). The inauguration itself took place just after the first inspection. The same people re-embarked at Toulouse on 15 May 1681 on a flagship boat followed by dozens of other boats. The
Cardinal de Bonzi, Archbishop of Narbonne and President-born of the
Estates of Languedoc joined the procession which arrived at Castelnaudary on 17 May. A great religious ceremony took place on 18 May at the Church of Saint-Roch followed by a procession to the canal to bless the work, the convoy, and the people present. The convoy resumed its progress on 20 May with stops in the evening at Villepinte, on the 21st at Penautier, the 22nd at Puicheric, and the 23rd at Roubia. On 24 May it was the passage through the
Malpas Tunnel then crossing the locks of Fonsérannes. The cardinal and the bishops went down to Beziers on the same day.
Supplementary works In 1686,
Vauban was made responsible for inspecting the channel which he quickly found was in a dilapidated state. He then ordered Antoine Niquet, the engineer of fortifications for Languedoc, to carry out new work at the
Montagne Noire level to drill the Cammazes Tunnel to extend the
Rigole de la montagne and strengthen the
Bassin de Saint-Ferréol. In his haste, Riquet had underestimated the number of rivers that in case of a flood would silt up and swell the canal. The barrage of Saint-Ferréol was too small and its supply system was inefficient. Vauban also built many masonry structures to isolate the many rivers that flow into the canal and spillways to regulate the water level. He built 49 culverts and aqueducts, including the
Cesse aqueduct, the
Orbiel aqueduct and the Pechlaurier culvert. Finally, he reinforced a lot of works and dams originally built by Riquet. This series of works, which lasted until 1694, greatly improved the supply and management of water. Antoine Niquet was responsible for monitoring the canal until 1726. The Canal du Midi still had shortcomings because it did not pass through
Carcassonne nor
Narbonne and did not join the
Rhône. In addition, to reach
Bordeaux, it was necessary to take the
Garonne which has variable flow rates and violent floods. The
Canal de Jonction or 'junction canal', built in 1776, gave access to Narbonne via the
Canal de la Robine de Narbonne. The same year the
Canal de Brienne allowed the bypass of
Bazacle - the ford on the Garonne in Toulouse which blocked the river. The connection between the
étang de Thau and the
Rhone was also completed in 1808. In 1810 a diversion canal allowed Carcassonne to be connected. Finally, in 1857 the
Canal latéral à la Garonne was opened between
Toulouse and
Castets-en-Dorthe, completing the link between the Atlantic Ocean and the Mediterranean Sea that Riquet had dreamt of.
Management Channel management was ensured primarily by the descendants of Riquet. This was through the elder son Jean-Mathias who took control of the fief until 1714, then Victor-Pierre-François until 1760, then Victor-Maurice, and finally Jean-Gabriel. The Riquet family quickly put up a pyramidal organisation structure with a "Director-General of the Canal" who governs a board of directors responsible for specific geographic areas of the channel. Seven zones were defined in the west and the east: Toulouse, Naurouze, Castelnaudary, Trèbes
Le Somail, Beziers, and
Agde. Each Director is responsible for maintenance of his zone and is supported by a receiver and a controller. Hundreds of lock-keepers are responsible for the locks. This organization facilitates the control and hiring of employees. In Toulouse, a group of three people form a steering committee: the director general of works, the Receiver General who sets the fees, and the Comptroller General in charge of accounting. Canal management ensures the supply of money to pay for various works and staff hired for the canal. In the 1770s a tax report showed an income of 640,000
livres, half of which went to maintenance and salaries, and half the profits and funds were exceptional works. In 1785 this benefit increased to 950,000 livres which was a very large sum for the time.
Maintenance . The maintenance of the canal was a real problem for the descendants of Riquet. Despite many precautions, the canal silts up with silt from the water supply. In addition, it fills with the branches and leaves of trees. Every winter, a period of closure allows the cleaning of the canal. It is necessary to re-dig the canal bed every year for two months. These works are expensive and two months is not always sufficient. Another problem is the invasion of the canal by weeds in the levels and spillways. There is no way to eradicate this scourge. In 1820 dredging was set up to pull up the weeds and the mud layer. Finally,
rain,
frost, and
drought forces managers to keep an eye all along the canal to repair leaks and cracks that might open. Today, the channel is subject to the same constraints and managers must perform the same work. They are now mechanized. Approximately 350 employees are made available to the Waterways of France manager by the
Ministry of Ecology, Sustainable Development and Energy to maintain the canal. ==Operational history of the canal==