Water and aquatic habitat quality

Water and aquatic habitat quality

Will the flow and turbidity of the Selune change with the removal of the dams? How will sediment continuity and habitat quality change?

The presence of dams has an impact on water flow, on fine sediments and on the dissolved chemical elements that pass through the river. These parameters play a major role in defining the quality of habitats for plant and animal communities and aquatic biodiversity. In addition, on the Selune, the works to dismantle the dams are accompanied by specific sediment management measures to avoid massive transfer of sediment downstream.

These parameters have been monitored since 2014 on either side of the (former) dams to understand their dynamics and the evolution of the ecosystem that is being restored.

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Map showing the location of the Sélune Observatory's fixed monitoring stations for assessing water, chemical and sediment flows.

Monitoring is carried out using continuous measurement probes and weekly water samples. They are used to assess variations in flow rate and water level, as well as concentrations of suspended solids and dissolved elements.

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Flow measurement station located downstream of the (former) dams at Signy, and calibration of a probe (Photos: O.Fovet) © Ophélie Fovet