Since the beginning of the 20th century the rivers of Europe, almost without exception have become polluted, channelled and fragmented by dams and weirs.
Word River Biodiversity Threat 2010
The result is a catastrophic reduction in biodiversity and water quality, accompanied by a widespread deepening of the riverbed and a massive loss of inundation plains and marshland to prevent flooding.
Only a few unspoilt and even fewer wild stretches of river remain.
The evaluations made and inventory prepared as part of the European overall water guidelines underline the urgent need for a reorientation of river management, linked with rigorous restoration policies. In spite of all the effort made over centuries, by 2015 only about a third all water courses had attained the required ecological condition.
The poor condition of our rivers can be attributed primarily to the unrestrained construction of dams for the purposes of energy production and irrigation, the policy of intensive agricultural and in part by a misplaced over-dimensioning of channelling for transport and a misplaced understanding of flood protection.
The basis of the ERN projects and campaigns places particular emphasis on the issue of the high concentration of dams and hydro power stations on the majority of river courses and the prevention of ecological free-passage for fish and debris. Reducing the overall number barriers of all types or their drastic modification can lead to very fast and significant regenerating of the dynamics of a river, stimulation of the self-cleaning process and to an increase in biodiversity.
Dams have severe negative environmental and social impacts
> Interruption of the ecological continuity,
- Blocking the Fishmigration
- Loss of Biodiversity
- Lack of sediment downstream of dams
- Deepening of the river bed, ground water level sinks
- Increasing flood impact downstream
- Disconnection of lateral water body
Example, the Rhine River : No more salmon wild salmon, Speed of water flow between Basel and Karlsruhe has doubled , Water retention is reduced
> Increasing Erosion of the coastline
Examples : Rhone rivers, heavy damned: Loss of 2 – 10 m land / year along the Camargue coastline (Rhone Delta), Saint Marie de la Mere will become a Island (Lack sediments – rising sea level). Same issues on the Ebro delta.
> Increasing water temperature in the reservoirs an the rivers
- eutrophication impacting water quality and ecosystems
> Displacing Millions of humans worldwide