The river Orge : one valley, one river, one Association.

The management of a river is the concern of all the inhabitants of a same valley.
It is for this reason that 32 communes are regrouped together in the Association of Communes of the Downstream Orge Valley (SIVOA).
As a result, the upkeep of the river and its banks, hydraulic management, decontamination and the monitoring of water quality are carried out more efficiently.

32 communes of the Essonne :
Arpajon, Athis-Mons, Ballainvilliers,
Boissy-sous-Saint-Yon, Brétigny-sur-Orge, Breuillet
Bruyères-le-Châtel, Égly, Épinay-sur-Orge,
Fleury-Mérogis, Grigny, Juvisy-sur-Orge,
La Norville, La-Ville-du-Bois, Leuville-sur-Orge,
Linas, Longpont-sur-Orge, Marcoussis,
Marolles-en-Hurepoix, Montlhéry, Morsang-sur-Orge,
Nozay, Ollainville, Paray-Vieille-Poste,
Plessis-Pâté, Sainte-Geneviève-des-Bois,
Saint-Germain-lès-Arpajon, Saint-Michel-sur-Orge, Savigny-sur-Orge,
Villemoisson-sur-Orge, Villiers-sur-Orge, Viry-Châtillon

Elected representatives and technicians working for the environment

64 delegates form committees dealing with ecology / the landscape, construction projects, finance…and decide upon the main decisions concerning the environment of the valley at a general meeting.

85 employees work in the operations, construction, water-quality, landscaping departments…
These employees are trained in the use of modern management tools - flowmeters, remote processing, geographical information systems - but they are also "ground troops" able to intervene at any time in the event of pollution or flooding in the valley.

Actions for the river Orge

Controlling the water levels
12 compensating / balancing reservoirs have been created to store the excess volumes of water which are transported by the river.
Furthermore, the acquisition by the SIVOA of land located in areas prone to flooding will prevent any further urbanization on the banks of the Orge.

Operating an inter-communal decontamination network
The SIVOA operates a decontamination network which runs from Breuillet to the lift station at Crosne: 142 km of canalisation and 22 lift stations to monitor, upkeep, rehabilitate…

The upkeep of areas of unspoiled nature
Each year, the SIVOA looks after 180 hectares of areas of unspoiled nature : mowing, clearing, pruning and water weed cutting. Much work has also been carried out to restore the banks of the Orge.

Improving water quality
As a slow-flowing urban river, the Orge recuperates water which flows into it and sometimes domestic water coming from the towns.
As a result of the decontamination work carried out by the SIVOA and the communes, the deterioration of the Orge has been halted.

Some key figures

142 km of canalisation
50 km of waterways
250 hectares of areas of unspoiled nature
...to upkeep