EU WATER LEGISLATION

Freshwater is not only an “in principle renewable natural resource” . Water is also a living environment composed of a diversity of aquatic ecosystems, habitats and species. In addition, Wetlands and terrestrial ecosystems directly depend on healthy aquatic ecosystems in terms of quality and quantity. Among the 13 400 groundwater bodies and 111 000 surface waters bodies, 80 % are rivers, 16% are lake and 4% are coastal or transitional waters . Surface water, transitional waters, coastal waters and groundwater provide a series of ecosystems services in terms of supporting , regulating , provisioning and cultural . In 2019, the IPBES’ report on Biodiversity and Ecosystem Services emphasised the value of the concept of Nature’s Contribution to People beyond an exclusively utilitarian approach. Everyone is aware that “water is indispensable for life and thus for our society and economy”. The European Parliament highlights that wetlands have different functions, such as serving as a carbon sink, a climate stabiliser, a clean water provider, a coastlines protector, and also in the mitigation of floods and droughts (…) .
Numerous scientific studies explain the ecological complexities of the water cycle and of the structure and functioning of aquatic ecosystems. Besides the biological diversity of aquatic environments, researchers demonstrate the high interdependencies between terrestrial, aquatic and marine ecosystems. For example, groundwater provides the base flow for surface water systems, so its quality may affect the quality of those surface waters. Researchers promote the necessity of adopting a holistic approach to better understand these interactions and the resilience of aquatic ecosystems exposed to different human pressures. “Water is the bloodstream of the biosphere. But we are profoundly changing the water cycle. This is now affecting the health of the entire planet” . A recent scientific publication demonstrates that the planetary boundary for freshwater has now been transgressed ; researchers have decided to assess the role of soil moisture and water available to plants (called green water) and not only the extraction of waters (blue water) .

Water and aquatic environment have different ecological, and physico-chemical characteristics and diverse vulnerabilities depending on their geographical location. The WFD underlines the vulnerability of aquatic ecosystem “located on the coast and estuaries or in gulfs or relatively closed seas, as their equilibrium is strongly influenced by the quality of inland waters flowing into them” .
The reports of the European Environmental Agency (EEA) illustrate this natural diversity due to, for example, the climatic conditions of the catchment area, bedrock geology and soil type. These all influence the water flow and the mineral content of the water. Their resilience to the pressures of human activities is thus very varied; as the EEA underlines: ”once pollutants are in groundwater, recovery from this can take years or even many decades because of residence times and the slow degradation of pollutants” .
Full comprehension of all these ecological complexities still faces several scientific uncertainties and a lack of data; they require further research and actions in order to be in line with the precautionary principle. The last report on the implementation of the WFD showed “a marked reduction in water bodies with unknown status and improved confidence in assessment”. The EEA underlines that for surface water bodies, “the proportion of unknown ecological status and chemical status fell from 16 % to 4 % and from 39 % to 16 %, respectively” .

The understanding of these ecological complexities is imperative to analysing the different pressures of human activities on water resources and aquatic environments. Such an integrated and ecosystemic approach must inspire the legal framework for human activities to ensure the protection of aquatic environments and the long-term sustainability of our water uses.
Water issues are not limited to pollution, even if this constitutes a substantial part of the problem. In addition, the assessment of the quantitative pressures on water resources cannot be disconnected from the assessment of human pressures and degradations of water quality and of aquatic ecosystems. In addition to the diversity of pollution sources (point source & diffuse source) and types of pollution (chemical, organic, physical), hydromorphological pressures constitute one of the major pressures which counteracts compliance with the objective of good ecological and chemical water status. Over-abstraction and water scarcity currently affect 6% of surface water bodies and 17% of groundwater ; in a climate change context, these pressures will increase and are likely to spread to several parts of the territory of the Member States. In 2021, the EEA highlighted that the main pressures on surface water bodies were hydromorphological pressures (34%), diffuse source (33%), atmospheric deposition (31%), point sources (15%), and water abstraction (6%) .