Modelling the effects of cross-sectoral water allocation schemes in Europe

Future renewable water resources are likely to be insufficient to meet water demand for human use and minimum environmental flow requirements in many European regions. Hence, fair and equitable water allocation to different water use sectors and environmental needs is important for climate change adaptation in order to reduce negative effects on human well-being and aquatic ecosystems. We applied a system of coupled sectoral metamodels of water availability and water use in the domestic, manufacturing industry, electricity generation, and agricultural sectors to simulate the effects of generic water allocation schemes (WAS) at the European level. The relative performance of WAS in balancing adverse impacts on the water use sectors and aquatic ecosystems was analysed for an ensemble of 16 scenarios for the 2050s, which were built from the combination of four socio-economic scenarios, developed in the CLIMSAVE project, and four climate projections based on IPCC A1. The results indicate that significant physical water shortages may result from climate and socio-economic change in many regions of Europe, particularly in the Mediterranean. In the energy sector, average annual water demand can largely be met even in water allocation schemes that deprioritise the sector. However, prioritisation of agricultural water demand has significant adverse impacts on the domestic and manufacturing industry sectors. Cross-sectoral impacts were found to be lowest if at least one of the domestic and manufacturing sectors is assigned higher priority than agriculture. We conclude that adapting spatial patterns of water-intensive activities to renewable water availability across Europe, such as shifting irrigated agriculture to less water-stressed basins, could be an effective demand-side adaptation measure, and thus a candidate for support through EU policy.