IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability

12.5 Adaptation: practices, options and constraints

12.5.1 Water resources

Climate change will pose two major water management challenges in Europe: increasing water stress mainly in south-eastern Europe, and increasing risk of floods throughout most of the continent. Adaptation options to cope with these challenges are well-documented (IPCC, 2001). The main structural measures to protect against floods are likely to remain reservoirs and dykes in highland and lowland areas respectively (Hooijer et al., 2004). However, other planned adaptation options are becoming more popular such as expanded floodplain areas (Helms et al., 2002), emergency flood reservoirs (Somlyódy, 2002), preserved areas for flood water (Silander et al., 2006), and flood warning systems, especially for flash floods. Reducing risks may have substantial costs.

To adapt to increasing water stress the most common and planned strategies remain supply-side measures such as impounding rivers to form in-stream reservoirs (Santos et al., 2002; Iglesias et al., 2005). However, new reservoir construction is being increasingly constrained in Europe by environmental regulations (Barreira, 2004) and high investment costs (Schröter et al., 2005). Other supply-side approaches such as wastewater reuse and desalination are being more widely considered but their popularity is reduced by health concerns related to using wastewater (Geres, 2004) and the high energy costs of desalination (Iglesias et al., 2005). Some planned demand-side strategies are also feasible (AEMA, 2002), such as household, industrial and agricultural water conservation, the reduction of leaky municipal and irrigation water systems (Donevska and Dodeva, 2004; Geres, 2004), and water pricing (Iglesias et al., 2005). Irrigation water demand may be reduced by introducing crops more suitable to the changing climate. As is the case for the supply-side approaches, most demand-side approaches are not specific to Europe. An example of a unique European approach to adapting to water stress is that regional and watershed-level strategies to adapt to climate change are being incorporated into plans for integrated water management (Kabat et al., 2002; Cosgrove et al., 2004; Kashyap, 2004) while national strategies are being designed to fit into existing governance structures (Donevska and Dodeva, 2004).