Monitoring the river, managing flows, maintaining the installations and the river bed, informing the users of the Rhone: all these activities belong to a rigorously managed and perfectly controlled system to ensure hydraulic safety.
In its capacity as the concessionary of hydropower development schemes, CNR has made hydraulic safety an absolute priority to ensure the safety of the people and property close to its installations. Hydraulic safety involves the design, servicing, maintenance structures and operating procedures of the installations (dams, plants, locks, dikes). Everything is managed rigorously according to specifications exclusive to each development and by a large number of regulations. Regular inspections are performed and reports sent to the supervisory authorities.
The operation of the hydropower development schemes (dams and plants) is subject to operating instructions approved by the DREAL (Regional Direction of the Environment, Agriculture and Housing). In particular, this defines the different operating conditions (normal, flood standby, flood), levels and flowrates to be complied with and the release alert procedures.
Our operators are housed close to the developments and are on immediate stand-by duty 24/7. They can intervene at any time and, if necessary, take manual control over the development schemes which are usually managed remotely from Lyon.
We spend an average of €90 M a year on maintaining and servicing our industrial and river facilities so that they are safe and in perfect working order. Long-term action plans aim in particular at predicting the ageing of the structures. More than 150 maintenance operations were performed in 2014. Maintenance is organised on the basis of centralised expertise and decentralised teams that are responsible for carrying out the operations on the development schemes.
We constantly monitor the hydrometeorological conditions of the Rhone and its tributaries to predict any hydrological event capable of affecting safety, production and other uses of the water. To do this CNR operates a measurement network (level, flowrate, rain) teletransmitted from 220 stations installed on the Rhone.
Regular monitoring of the evolution of the river bed makes it possible to launch maintenance operations at the right time: remove ice-jams, pruning, ploughing and dredging-cleaning. This hydrological and sediment monitoring allows CNR to ensure good flow conditions for the river and its tributaries and adapt the operations of its facilities in the case of low flows, i.e. low water levels.
We rely on a quality management system for which CNR is certified ISO 90001 (2008 version). Regarding prevention, hazard studies identify potential risks (events either inside or outside the facilities), formulate possible incident/accident scenarios and describe the hydraulic impacts. They propose measures to reduce risks and concrete actions for improvements. By the end of 2014, CNR had completed hazard studies for its 19 hydropower plants.
The “release alert” is a systematic procedure whereby all openings of dam gates must be preceded by a slow and progressive release of water. This procedure warns the public of a rise in the water level and gives people enough time to leave floodable areas where they may have ventured in spite of the warning signs.
Every year on the banks of the Rhone, CNR carries out a campaign to make the neighbouring population and tourists aware of the risks of being close to the installations. This campaign, which has as its mascot Louloute the Otter, is carried out in collaboration with the Prefecture and local actors.
CNR’s 14 wide gauge locks are remotely controlled and monitored 24/7 by the Navigation Management Centre (NMC) installed at Châteauneuf-du-Rhône. The NMC therefore plays an essential role in ensuring the safety of navigation through its global vision of river traffic. In addition, every year CNR carries out major lock inspection and maintenance operations during a scheduled period when navigation is stopped. These interventions are all concentrated into a 10-day period to minimise their impact.
CNR ISO certifications cover quality management for all its activities and its environmental approach.