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Diagnose physical alterations in rivers

 

 

 

 

Alterations in the morphology and the hydraulic regime of rivers have become major factors in river degradation. That is why the Water framework directive now requires that the hydromorphological characteristics of rivers be taken into account in evaluating the ecological status of surface waters.

Onema is in charge of setting up the national monitoring programme for the morphology of rivers and lakes in France. An in-depth diagnosis will reveal the main physical alterations, look for the causes and indicate the best solutions for the necessary restoration work.

Ecological continuity is now a priority among hydromorphological alterations. Almost 60 000 obstacles, including dams, locks, weirs and mills no longer in operation constitute obstacles on rivers in France, disturb aquatic life and block sediment transport. French and EU regulations (WFD, Water law, national eel-management plan, Grenelle environmental laws, national restoration plan) now make it mandatory to restore the ecological continuity of aquatic environments. They collectively require that water stakeholders increase their efforts and projects in favour of restoration. This will be a major issue in the years to come and Onema is already in the starting blocks.