Channel of Marseilles

The Channel of Marseilles , is one of the independent sources of provisioning of Drinking water of the town of Marseilles. Of a 80 kilometers length for its principal part (160 kilometers with derivations in the city), it serves the entirety of the districts of Marseilles. It was built in the middle of the XIXe century in about fifteen years under the direction of the engineer Franz Mayor de Montricher, bringing water of the Durance in the city on July 8th 1849. It represents an outstanding realization of the engineering of the 19th century by cumulating very many infrastructures, bridges, tunnels, tanks… Until 1970, it was the independent source of water supply of the town of Marseilles; it still provides the two-thirds of the water resource of the city.

Origin of the channel

Marseilles, located in seaside and enclosed in the hills, is crossed only by a river with the low and very irregular flow: the Huveaune, and its affluent the Bulge, channeled as of the 14th century, but become with time a kind of sewer with open sky. Until the 19th century, the city had only well for its water supply -- one counted of them 10 to 12.000 at the end of the 18th century. Water was polluted more and more and a growing share was lost by it because of the absence of maintenance of the distribution network.

However, the epidemics accompanying the severe drynesses made devastations. In difficult period, the flow of Huveaune made it possible to use 75 liters of water per day and anybody. But in 1834, it was practically drained and only 1 liter per day was available by anybody. Fast population growth of the city (: 140000 inhabitants in 1830) and especially the epidemic of Cholera of 1832-1835 convainquit elected officials to act to restore healthiness and to ensure the quantity necessary of water for the City.

This epidemic, superbly described by Jean Giono in Hussard on the roof, makes approximately: 100000 died in all the hexagon. Of Indian or Asian origin, the disease had been spread along the valley of the Gange in 1826, then of the Caspian Sea and the the Volga in 1829. In 1830, it gains Moscow, then the Poland, Hamburg in 1831. In March 1832, the cholera reached Paris, where it makes: 18402 died, and decimates the population in High-Provence. In July 1833, the epidemic reaches Marseilles, in December 1834, it makes 865 dead, then still: 2576 in 1835.

These epidemics come to revive terrors of the population and especially in Marseilles where the memory of the plague of 1720 remains in all the memories. In July 1833: 30000 Marseillais gather in procession in the center of the city.

Maximin-Dominique Consolat, mayor of Marseilles of 1832 to 1843, decided in 1834 " though it occurs, no matter what it in coute" to make come to Marseilles water from the river nearest, the the Durance, however remote and separated from Marseilles by many mountainous links ( chain of the Coasts , plate of the Alpine laburnum , Massive of the Star). Water was to be collected rather high on the Durance to be able, by simple gravity, to carry out all the course, circumventing or crossing the intermediate hills, and to arrive to Marseilles at the point highest of the city, in Saint-Anthony (altitude 150 meters), so as to serve it entirely.

The realization of the Channel

It takes fifteen years, of 1839 to 1854, to build the channel, with its tormented layout, its 80 km length including 17 km in undergrounds, its 18 bridges, of which the aqueduct of Roquefavour.

Indeed, one of the main difficulties was to make cross to the channel the valley of the Arc, whose altitude is lower than 100 meters between Aix-en-Provence and the pond of Berre. The engineer Franz Mayor de Montricher, in charge of the realization of the project, refused the proposal of a bridge Siphon, however more economic, and decided to carry out a Aqueduc between two points where the plates bordering the Arc in north and the south were rather close so that the work has a reasonable length (less than 400 meters): it was the Aqueduc of Roquefavour, architectural work inspired of the Pont of Gard Roman, and considered since as one of the monuments to visit in from Aix area. The aqueduct has length a 393 meters and the channel passes to 82,5 meters above the Arc.

The course through the Rhone delta

The initial hydrant was located on the Durance at the level of the bridge of Pertuis, at an altitude of 185 meters, and at 50 kilometers as the crow flies of Marseilles. From there the channel left towards the west under Puy-Holy-Réparade, the then north-western one until Saint-Estève-Janson.
During the construction of the large channel EDF, which doubles the Durance since Greenhouse-Ponçon until Living room-of-Provence and the Etang of Berre, the hydrant of the channel of Marseilles was deferred on channel EDF itself, after Saint-Estève-Janson. From there the channel of Marseilles continuous towards the North-West to the bridge of Cadenet, where it supplies the basin of Saint-Christophe .
He then starts to cling to the hills, passes above Castling-with Anthéron and Charleval, then leaves the Durance and channel EDF, forks towards the south, and passes in a long tunnel under the western end of the chain of the Coasts .

After Lambesc, its profile becomes more run up: many bridges and especially tunnels are necessary for him to cross the small valleys and the hills until Coudoux. It circumvents by the east the hill of Ventabren, and arrives above the Arc, which it crosses by the Aqueduc of Roquefavour.

Since Ventabren, the channel neighbor on several occasions with the line at high speed Paris-Marseilles. The viaduct of the LGV on the Arc was drawn besides for a harmonization with the aqueduct of Roquefavour.

The continuation of the course is carried out through the plate of the Alpine laburnum , which, in spite of its name, is hardly flat: tunnels and distinct are still numerous, to the tank of Réaltor (altitude 170 meters), on the commune of Cabriès.

A tunnel of 3 kilometers makes him cross the southern end of the plain of Alpine laburnum to the treatment plant of the Giraudets (common of the Pennes Mirabeau), then a second of 2 km brings it to the Northern entry of Marseilles, in Saint-Anthony.

The service road of Marseilles

Saint-Anthony (15th district of Marseilles), a first junction leaves to the West in direction Estaque (16 {{E}} district). The principal channel circumvents the small valley of the Aygalades , and clings to the sides of the chain of the Star in direction of the east. To the place known as Furnace of Buze , an emissary goes to the tank of the Merlan and from there goes down towards the Fall-Lavie and the Palais Longchamp .

The arrival of water and the construction of the underground tanks, two gigantic mud tanks of 4250 m ² and 4900 m ², carried out in 1854 pennies the Longchamp Garden, give place to the creation of the Longchamp Palate in 1862 by the architect Espérandieu. Unfortunately, the silts of the Durance make quickly them ineffective and the construction of other equipment is necessary. The problem of filtration of water of the Durance will be solved only in 1882. These basins will be unused in 1969. The decoration of the Palate with the marine statues, the cascades and the jets of water illustrates the joy which the Marseillais test with the idea to at will lay out finally of water.

The channel of Marseilles today

The water quality of the channel of Marseilles

Today, the channel of Marseilles does not ensure only any more the water supply of Marseilles. Built in the years 1970, the Channel of Provence, a canal system on the basis of the the Verdon, an affluent of the Durance, and underground in its almost totality, feeds not only Marseilles (tank of Small valley Fraud), but also Aix-en-Provence (dams Bimont and Zola) and Toulon. Today, the water of the Durance transported by the Channel still counts for the two-thirds of the water resource of Marseilles, the remaining third comes from the Verdon by the Channel of Provence. The two resources are inter-connected, which ensures the security of the supply.

The water of the Channel is treated in the two factories of drinking water Production of Holy-Marthe and Saint Barnabe. The principal stages are Pre-chlorination, Clarification by flocculation by means of a coagulant, filtration on sand and disinfection by the Ozone and the Chlore. The analyzes led throughout the year 2006 by the Management of the Public health of the Town of Marseilles on water shows very a bacteriological good quality and appears in conformity with the standards as for the presence of pesticides (measured value lower than the threshold of detection) or of nitrates (less than 2 mg/l for 50 mg/l of maximum standard) which testifies to a water not having undergone agricultural contamination of source. On the other hand the water of the Durance presents a high value of Dureté (23°F) which makes it qualify earthy water .

The management of the channel

Of its delivery in 1849 to 1941, the Channel was managed by the Town of Marseilles. Following the catastrophic fire of the New Galleries of Marseilles which made 73 dead in November 1938, the town hall of Marseilles was placed under supervision. In 1941, the management of the water of the city, and thus the Channel, are entrusted to the Survey firm of Water of Marseilles (Seem) because of its knowledge of the network by the studies which it carried out since 1934. In 1943, according to a convention of the " type; control intéressée" , the town of Marseilles, which remains owner of the works, entrusts the exploitation of it to Seem. This one becomes the Company of Water of Marseilles (Sem) officially on March 1st, 1943. Raoul Dautry, which contributed to the creation of the National company of the railroads French (the SNCF) in 1938, is named by it the first President.

Since then, the Company of Water of Marseilles, held with equal share by Veolia (ex General Company of Water) and Lyons of Water (subsidiary of Suez Environment), become the Group of Water of Marseilles, manages the Channel of Marseilles, which is the backbone of the drinkable water supply in the City and many surrounding communes.

The safety of the channel

In all the part except Marseilles, put aside obviously the underground sections, the channel is with the free air and can be followed thanks to ways on banks. Inside Marseilles, for obvious safety reasons, the company of the channel of Marseilles undertook to enclose or cover all the sections crossing public spaces, with the great regret of in love with running water. Indeed, the channel can represent a true danger, in particular for the children.

With a current reaching 0,7 meter a second on average, the speed of water can accelerate constantly in the event of opening of valves. Moreover, the walls of the channel are sloping and slipping and prevent very gone up.

Also, the Company of Water and the city multiplied and still into 2007 the campaigns warning and set up of the security measures: nettings, panels, barriers, floating life lines and even guarding in the most significant places, near the dwellings.

Maintenance

Taken in Sainte Marthe, the raw water is filtered in the basin of the Whiting (14th district), before leaving in the distribution network under pressure. But the Channel of Marseilles does not have only one interest medical. As of its creation, it modified the Marseilles landscape while allowing the farmers and the owners to sprinkle the fields and the gardens of the country houses. It was the beginning of the truck farming in Marseilles, thanks to the gravitating irrigation channels which left the channel and went down towards the city.

To maintain its branch “mother” and her drains, the Channel of Marseilles has its own technicians, the aygadiers, who have right-of-way in the private properties, operate the Martelière S and the pumps. But the Company of Water of Marseilles, which inherited the channel and of its aygadiers wants to center itself on his trade (drinking water), it thus seeks to close all the irrigation channels on the basis of the channel. For that, it does not renew the rights of water to the new owners and proposes an irrigation by water under pressure. Gradually the drains are given up, and the SEM removes the posts of aygadiers. Nearly forty 20 more years ago, they are not any more but one dozen to manage the 80 km of the channel.

" researchers of fuite" are a fortnight and are charged d'" écouter" the drainage duct under the ground, with geophones (amplifying of sounds until 4000x) to today detect the escapes on the drains. By their effectiveness, the network has an output of 85%, which is regarded as good level.

The channel, tourist site and object of culture

Stroll

The channel offers many sections favourable with the walk and the sights on nature of Provence throughout its layout. Cycle tracks and ways are arranged or in project in all the department and mêm downtown.

The remarkable sites and portions are:

the Aqueduct of Roquefavour, close to Aix-en-Provence
the Longchamp Palate in the center of Marseilles
the tank of Holy Marthe
banks of the channel on the plate of the Alpine laburnum

The channel at Pagnol

Marcel Pagnol, in his memories (the castle of my mother), tells that, to go to their " campagne" from the Treillised vineyard, his/her father had obtained from a guard of the channel, one named Bouzigues, the key enabling him to skirt the channel in the crossing of private properties, shortening several kilometers the way. On the ground, it is difficult to determine which was this short cut. The veracity of the anecdote could be only… partial.

The Ziem painter, architect of the channel

Ziem share for Marseilles in 1839. It is engaged as section engineer at Mr. de Montricher who makes studies of the channel. This last presents to the Duc of Orleans of passage to Marseilles, two watercolours of the Ziem young person. Thus in 1840, the Duke of Orleans orders three watercolours to him. Ziem is devoted consequently to its career of painter and draftsman. It opens a workshop of drawing in Marseilles.

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