Water resources: quantity and flows - SOER 2010 thematic assessment

While water is generally abundant in much of Europe, large areas are affected by water scarcity and droughts — particularly in the south with its severe lack of, and high demand for, water. A comparison of the impacts of droughts in the EU between 1976–1990 and 1991–2006 shows a doubling in both area and population affected. Climate change is projected to exacerbate these impacts, with more frequent and severe droughts projected for many parts of Europe.

Water scarcity has severe consequences for most sectors, particularly agriculture, tourism, energy and the provision of drinking water. Activities that depend on high water abstraction and use, such as irrigated agriculture, tourism and the use of cooling water, are affected by changed flow regimes and reduced water availability. In many locations, water demand often exceeds availability, and the need for adequate water supplies to service vulnerable ecosystems is often neglected. Over-abstraction is causing low river flows, lowered groundwater levels and the drying-up of wetlands, with detrimental impacts on freshwater ecosystems. For many European countries, much of the 'water footprint' (an indicator for direct and indirect water use) is imported from wherever production takes place (virtual water), causing potential water stress abroad.

Over the past ten years, Europe has suffered more than 175 major floods, causing deaths, the displacement of people and large economic losses. Climate change is projected to increase the intensity and frequency of floods. Most of the observed upward trend in flood damage can be attributed to socio-economic factors, such as increases in population, wealth and urbanisation in flood-prone areas, and to land use changes, such as deforestation and loss of wetlands and natural floodplain storage.

Over the past 150 years Europe's freshwaters have been affected by: major modifications by dams, weirs and sluices, which reduce connectivity; straightening and canalisation; and the disconnection of floodplains. Such structures and activities have altered many European water bodies, sometimes leaving little space for natural habitats, obstructing species migration, disconnecting rivers from floodplains and wetlands, and changing the water flow.

Because of water scarcity and physical modifications (and poor water quality), many European water bodies are at risk of failing to meet the aim of the EU Water Framework Directive (WFD) to achieve good status by 2015. Overall water demand in most of Europe is expected to be stable or to decrease (due to increased efficiency), although many river basins will continue to face high water stress due to high demand for water compared with availability. Climate change is projected to increase water shortages, with more frequent and severe droughts projected for many parts of Europe (e.g. Mediterranean region). Flood hazards are also projected to increase across much of Europe. There are also many plans for new dams, reservoirs and small hydropower projects that may further modify Europe's water.

At the same time, win-win solutions for managing water use and improving ecological status are beginning to emerge. Examples include making room (space) for rivers, protecting and developing wetlands, and fostering rainwater infiltration in urban areas.

To meet the needs of a resource efficient future, sustain human and economic development and maintain the essential functions of our water ecosystems, an integrated approach to water resource management is needed. Full implementation of the WFD and other water policies will be required to reach good status by 2015. The EU 2020 Strategy and the European Commission's 'Blueprint for safeguarding European waters', planned for 2012, will also further promote sound water management.

Unfortunately, some policies (e.g. hydropower, bio-energy crops) threaten the achievement of water management objectives. There is thus a need to strike a balance between the benefits of such policies (e.g. renewable energy) and the impacts on the ecological status of water bodies, adjacent land ecosystems and wetlands.

Europe cannot endlessly increase its water supply. Rather, it must reduce demand and policies are needed to encourage demand management. Demand measures could include: the use of economic instruments; water loss controls; water-reuse and recycling; increased efficiency in domestic, agricultural and industrial water use; and water-saving campaigns supported by public education programmes.

Flood management should shift from its current focus on hard-engineered defence systems to natural measures based more on slowing and storing water (e.g. by floodplains and groundwater aquifers) and providing adequate space for rivers. The environmental impacts of water engineering projects (e.g. dams and navigation) should also be minimised.