B - High ecological complexity
As mentioned above, hydromorphological alterations constitute the major pressure on water bodies. Different human activities (agriculture, energy production, transports, land planning) have affected the morphology and hydrology of freshwater bodies. 17% of European water bodies have been identified by Member States as heavily modified (13%) or artificial (4%) water bodies due to old or continuous alterations over decades. Sediment run-off from the land can make water muddy, blocking sunlight and, as a result, kill wildlife. Irrigation, especially when used improperly, can bring flows of salts, nutrients and other pollutants from soils into water. The physical management of rivers and the wider hydrological environment of a river basin, such as by canalisation, dam building, or riverbank management can disrupt natural habitats, such as bank side vegetation.
The existence of hydropower plants is one of the reasons given by Member States for designating such water bodies. Dams, flood protection infrastructure, land drainage, water storage reservoirs (…), are different sources of hydromorphological alterations ; such actions or barriers modify the natural water flow regime, affect, even break the continuity of rivers and contribute to river fragmentation as well as the decline of biodiversity. The EEA explains that “20% of surface bodies are affected by barriers as a significant pressure”; it also indicates that “for 40% of affected water bodies the purpose of the barriers is unclear”
. It underlines the importance of the restoration of disconnected wetlands and floodplains, in particular in the context of the implementation of the Floods Directive
, the adaptation to climate change
and the Natura 2000 Network
.
Recent scientific studies show that river fragmentation is a major challenge with “at least 1,2 million instream barriers in 36 European countries” . At the same time, the promotion of energy production from renewable sources leads some Member States to increase the efficiency of exiting hydropower plants and also to invest in new hydropower plants. The promotion of more sustainable modes of transport also raises the issue of the ecological impacts of inland waterways (around 40 000 km), in particular in central Europe.
Given all these ecological complexities and the diversity of human pressures on freshwater, an integrated and ecosystemic approach is essential, especially to address current emergencies. The WFD promotes the implementation of the concept of Integrated Water Resources Management defined by the Global Water Partnership as “a process which promotes the coordinated development and management of water, land and related resources, in order to maximise the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems” . The new EU Environment Action programme up to 2030 also promotes the ecosystem approach “for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way in order to help reach a balance”
between the objectives of conservation, sustainable use and benefit sharing of biological diversity.
The EU is clearly a key player in water governance and the legal framework. Its contribution, together with its Member States, without forgetting the role of the judges, must be exemplary and a driving force in respect of the principle of subsidiarity and a high level of environmental protection. While the WFD is the centerpiece of EU Water Policy, the EU Water Law has a complex architecture (Part II).