It wasn't immediately obvious that a canal aqueduct needed to be built here, and it was only when the railroad opened between Toulouse and Sète that this project came to light. Orb aqueduct is a majestic engineering structure very close to the famous Fonseranes locks, and is a must-see of the Canal du Midi!
When the Canal du Midi was opened to navigation in 1681, boats had to cross the Orb river, along a 828-metre shared section.
However, it was not easy to sail along the Orb. Water levels were often very high, causing many problems for skippers. Navigation was suspended for approximately 40 days per year and the raging waters carried vast amounts of alluvium which clogged up the channel.
Costly work was regularly carried out to repair engineering structures.
In 1756, Charles-François Ribart suggested building an aqueduct so that it would no longer be necessary to sail along the unpredictable waters of the Orb. But a structure of this magnitude came at a certain cost and there were no available funds! In 1780, architect Claude Nicolas put forward another proposal, which was also rejected!
It wasn't until the railroad opened between Toulouse and Sète that the Compagnie du Canal du Midi agreed to build a canal aqueduct. Without this structure, boats would likely remain blocked on the edge of the river when water levels were high. But the trains wouldn't have this issue! This competition needed to be addressed...
It was chief civil engineering engineer, Urbain Maguès, director of the Canal du Midi, and division engineer Simonneau who would begin working on this structure in 1853. There was a ceremony to mark the beginning of the construction work on 3 October 1854. At this time, the bridge for the railroad was almost completed. The construction of the aqueduct went according to plan and the structure was inaugurated on 13 November 1857.
Urbain Maguès demonstrated impressive talent in designing the structure. The façade of Orb aqueduct was built using cut stone and there were elegant archways in between each side wall.
This design meant that the navigation channel could be very wide without creating an overbearing weight or volume.
People spoke very highly of this structure when it was under construction, with comments such as "This enormous structure will be one of the most beautiful features of the canal, and its most remarkable characteristics will be the galleries on either side of the tympanums, with a series of ninety-three archways in between".
Orb aqueduct has a classic design, and with the patina of time, it looks like it was built in the 17th century, at the same time as the Canal du Midi!
Orb aqueduct is 242 metres long. The canal crosses over the Orb thanks to this seven-metre-high structure with seven arches, and seventeen metres wide. There is a towpath on either side of the navigation channel.
At the end of the aqueduct on the downstream side, Orb lock then leads to the Port-Neuf de Béziers marina. After Béziers lock, the Canal du Midi joins back onto the 17th century route. The aqueduct, lock and marina were all built at the same time.