The aqueduct at Roquefavour, carries the water of the Canal de Marseille across the River Arc where it runs between the town of Aix and the district of Ventabren. For those of you that have not yet visited this magnificent structure, you can find it by taking the D 65 from Les Milles; it is well worth seeing.
Since the Greek period (around 500 BC), Marseille had been drawing water from various artesian wells, small rivers and springs surrounding the city. In the early 1830s water was taken from the rivers Jarret and Huveaune, but due to pollution there was a cholera epidemic, leaving the local population in a state of panic. Then in 1834, after a particularly bad drought and the constant threat of disease, the Marseille City Council decided that a river diversion canal should be built more or less regardless of cost to provide adequate clean water for Marseille and the surrounding areas.
Jean-François Frantz Mayor de Monticher, a 24 year old public works civil engineer, was given the task of designing and overseeing the project. The subsequent Canal de Marseille, which originally took water directly from the River Durance, took fifteen years to complete and covers approximately 80 kilometres. The biggest obstacle for this project was the crossing of two very large hills at Roquefavour which stood almost 400 metres apart, with the added difficulty of the Arc valley being nearly 90 metres below the water flow. After investigation and consideration, the engineer put forward proposals to construct an aqueduct, but he suggested using a different type of structure from any that had been previously contemplated.
In April 1842 the Ministry of Public Works authorised the construction and the first stone was placed when building work began on September 19th 1842. The first level took nearly three years to complete due to the enormous size of the arches; each of the twelve arches being over 34 metres high and 15 metres wide. The building of the second level (15 arches, each being slightly bigger than the lower tier) began in January 1846 and took just under a year to complete. The third level with 53 smaller arches only took 5 months to complete (May 1847) and water diverted from the Durance first flowed across the aqueduct on the 30th June 1947. The work had been completed without a single accident.
Obviously, to complete this work many people were employed. For example, 300 stone artisans worked for a year in two quarries near Velaux, just extracting and facing the necessary rocks. A nine kilometre railway was built to take the blocks of stone from the quarries to Roquefavour using 120 railway wagon containers for the transportation. An indication of the sheer size of the building is the fact that some of the lower stones are 6 cubic metres in size and weigh 15 metric tons each. The overall structure is made up of 66,000 cubic metres of stone, of which 50,000 are faced and the total cost was just under FF 3.8 million. God only knows what it would cost to build in today’s money!
The Canal de Marseille is now the source of water for the City of Marseille and 36 other communes in the Bouches-du-Rhône. All of the water still emanates from the River Durance but nowadays is taken from the Canal EDF at St Esteve-Janson. The water crosses the aqueduct at a rate of 17 cubic metres per second. The better known aqueduct, the ‘Pont du Gard’ is actually dwarfed by our local masterpiece; the Roman built aqueduct being only 275 metres long and 49 metres high. L’Aqueduc de Roquefavour is the highest stone-built aqueduct in the world.