large EDF canal, which follows the Durance from Serre-Ponçon until Salon-de-Provence and the Étang de Berre, the water for the canal of Marseilles is now taken from the EDF canal, below Saint-Estève-Janson. From there to Marseille the canal follows an path, of which is underground. The Durance provides today two-thirds of the water for the city of Marseilles. Hydroelectric installation In 1955, the law defined the EDF Durance-Verdon project had three objectives: production of electricity; irrigation and the supply of water to towns; minimisation of the flooding. Over 40 years, this project required the construction of 23 dams and water extraction points starting upstream of Claux sur Argentiere down to Mallemort and the supply of 33 hydroelectric power stations and several control stations. This programme was an almost complete success: the Durance-Verdon project produces 6 to 7 billion kWh per annum (10% of the French hydroelectric production); the reservoirs provide drinking water to the whole area, and irrigate all of Provence (a third of all French irrigation); the lakes are a tourist attraction (Serre-Ponçon attracts 10% of the tourists visiting Hautes-Alpes); although routine floods are prevented, the project cannot have any effect on major floods, as shown by the flood of 1994, which reached in Cadarache. Indeed, the lake at Serre-Ponçon only controls the upper reaches of the Durance, and does not control the lower tributaries, whose role is important in the creation of the major floods. All the other dams are only to abstract water. Only the flow of the Verdon is controlled by a dam, Lac de Sainte-Croix, and only if there is enough storage capacity at the time of the flood. Impact of the works The Durance used to have an average natural flow of and behaved like a Mediterranean river, but dams and canals have changed it considerably. When the flow is low, most of the water in the river now flows in "industrial channels" which by-pass the natural course of the river to run through hydro-electric power stations. These channels can take up to , so that it is only at the time of high flows that the water not diverted uses the river's natural channel. Ecology Along the river there are many habitats of both regional and European importance that are naturally governed by the varying flow of the river. These habitats include both mountain and Mediterranean types. The river with its valley is