Home - Themes - Policing activities -Major efforts to protect aquatic environments from large linear-infrastructure projects


    -Bruno Becker \ Eiffage
    "ERE and CLERE are the EIFFAGE companies in charge of building the high-speed train line between the cities of Le Mans and Rennes. About 25 people ensure that both the design and construction of the project comply with environmental regulations..."

Major efforts to protect aquatic environments from large linear-infrastructure projects

France is criss-crossed by a network of linear infrastructure (railroads, highways, pipelines, etc.). These installations can have a significant negative impact on natural environments, i.e. breaks in the ecological continuity of rivers, destruction of wetlands, cutting of trees, etc. To ensure the best possible environmental integration of these large linear-infrastructure projects, Onema, in support of the other State services, must intervene as early as possible in these exceptional projects that simultaneously affect numerous rivers and wetlands that, most often, are of major ecological value.

Its regional and local offices are called upon to ensure continuous monitoring during the design phases and the construction and operational phases. They must check the legal validity of all administrative documents and ensure that WFD conditions are met. Finally, they must also run inspections to check that the project meets all applicable environmental standards.In 2012, Onema played an active part in three major high-speed train lines (LGV), namely the Bretagne-Pays de Loire LGV, Eastern Europe LGV and Southern- Europe Atlantic LGV

Bretagne Pays de la Loire LGV, face to face with reality

The Bretagne Pays-de-la-Loire regional office and three local Onema offices were involved in the extension of the Paris- Le Mans LGV to the city of Rennes. The project was launched in 2012 and represented 182 km of new line through the Sarthe, Mayenne and Ille-et-Vilaine departments. The objective was to ensure that the work done by the Eiffage company did not degrade nearby water bodies. The line crossed 118 rivers and led to the destruction of 254 hectares of wetlands. The job for Onema was to ensure that the compensatory measures were effectively implemented by the company. That required on-site presence for inspections every week in the three departments, in conjunction with the departmental territorial agency and ONCFS. The inspections, both scheduled and unscheduled, revealed that the company made real efforts to limit the impacts. The number of inspections will increase in 2013 and 2014, during the main earthmoving work. There are also plans to set up a compensation monitoring system, with regular meetings, to ensure that the compensatory measures are in fact implemented in the field.

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Eastern LGV, advice to limit negative impacts

In 2010, the second phase of the Eastern LGV was launched to reduce travel time between Strasburg and Paris to less than two hours. The RFF (French rail network) company constructed the 106-kilometre line crossing the Moselle and Bas-Rhin departments. The Onema regional office in Metz and the local offices were called upon to provide technical opinions concerning water regulations. The work resulted in «partitioning» the environments on either side of the line. That is why 150 hydraulic installations were modified to ensure ecological continuity for aquatic fauna. In addition, Onema provided technical advice on how to compensate the significant residual impacts, in particular the destruction of 33 hectares of wetlands. Onema personnel advised RFF on compensatory measures to restore damaged wetlands. Corrective measures for aquatic habitats were undertaken for 40 permanent alterations in rivers. The inspections with the departmental territorial agencies have produced results in that of the 50 hydraulic installations found to be non-compliant, three-quarters will rapidly be corrected.

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Southern-Europe Atlantic LGV, acquiring the correct reflexes

To limit travel time between Paris and Bordeaux as well as establish the connection between France and Spain, the State decided to build 340 kilometres of new, high-speed track. The company selected for the project started work in 2012 and the trains should be running by 2017. The new line, which crosses six departments and three regions, will considerably impact the environment. The Onema regional offices in Orléans and Toulouse, plus the local offices, were active starting in 2007 to assist the State services in preparing the project. They also provided their know-how to ensure that the impacts on the environment were reduced to a minimum, particularly during the construction phase. Onema made sure suitable clarifiers were installed along the work sites to avoid any sedimentation finding its way into rivers and nearby wetlands. Particular attention was paid to the ecological continuity of the 88 rivers crossed by the line, given that a total over 500 hydraulic installations were planned. With the departmental territorial agencies, Onema personnel ran a large number of inspections on the temporary installations. The goal was to ensure that the construction company knew what was expected for the final installations, in compliance with the technical specifications.

A novel partnership in the Pyrénées-Orientales department

After receiving a citation from Onema for work in a river not in compliance with the Water law, the Pyrénées- Orientales Council recontacted Onema to analyse the problem and attempt to correct it. Onema and the departmental territorial agency decided to set up a new training programme targeting two goals, 1) raise awareness of managers at the Roads service concerning the need to take aquatic environments into account on work sites and 2) present the best practices reconciling river work with environmental protection right from the design phase. The course, designed as part of the quality policy of the Roads service, was given a second time for some 50 technical agents directly involved in managing or working on road projects and the technical agents of a river board. The information on how aquatic environments work, on applicable regulations and on the feedback from well-run work sites helped in learning the best practices and in applying the «avoid, reduce, compensate» principle for environmental impacts.