The Donzère-Mondragon development is located in the Bas-Rhône, between Montélimar and Caderousse and is the second project to have been constructed after that of Génissiat. It is also the most productive, (2.14 billion kWh, which is 13% of the hydroelectric power production of the Rhone), as well as being the first project to respond to the triple objective of the initial specification ; production of power, irrigation and navigation.
Before the site was opened, the dimensions of the lock were the subject of lively debate, especially since the lock would serve as a model for subsequent projects. CNR had a 9-metre long, under-arch propeller tugboat constructed (the Frédéric-Mistral-Rhin-Rhône), in order to prove that this type of propulsion could be used on the Rhone, thus avoiding the necessity to adapt to the tugboats of the time, the beams of which were nearly 20 metres!
The evidence was conclusive and the dimensions of the lock were limited to 12 metres in width and 195 metres in length. With its 23 metres height and fill speed of 10 minutes, it established a new world record.
The gigantic site mobilised nearly 7000 workers, for which seven housing estates were constructed, with all the equipment necessary for their daily life and those of their families.
The power station installed at Bollène is equipped with six production groups, each turbine capable of reaching 59 MW power. Six gate-dischargers installed on the left bank of the river, permit the evacuation of overflow water in the event of a sudden stoppage of the power station. The formation of waves upstream which are dangerous to navigation, can thus be avoided.
The development carried out between Donzère and Mondragon has also allowed the elimination of the area known as “the rapids”, which extended over 30 km and was particularly difficult for navigation.
Where the development of agricultural land is concerned, the creation of around ten water supply points has made the irrigation of 9000 hectares possible. The execution of the development has also led to a vast land consolidation programme, as well as the installation of a drainage network on marshy terrain, thus rendering this suitable for cultivation.
On the economic development side, the installation of two industrial-port complexes at Bollène and Mondragon constitutes an important asset for the region.
Finally, numerous actions have been undertaken in the environmental field, amongst which of particular note are; the restoration of pond channels in association with different local and national partnerships, the development of a fish passage near the dam and the preservation works on the phreatic nappe.
Find out more :
- Sketch of Donzère-Mondragon development (Format pdf - 66.6 kb - 28/02/2008)