Abstract ID: 3.13797 | Accepted as Talk | Requested as: Poster | TBA | TBA

Once water-abundant, parts of the Alps are now experiencing more frequent water scarcity and drought conditions, impacting both human activities and ecosystems. In addition to lower water availability due to climate change, water scarcity is also strongly shaped by how water resources are allocated, used and managed. It thus represents a socio-hydrological phenomenon that concerns all sectors reliant on water and their interdependencies, i.e., the Water-Energy-Food-Ecosystems (WEFE) Nexus. While previous research on the WEFE Nexus in water-scarce contexts have primarily focused on hydrological analysis, this study employs a mixed method approach to reveal hydrological, social and governance conditions that jointly contribute to water scarcity. The approach is applied to the Orco catchment, a sub-basin of the Po River in Northern Italy, characterised by significant storage capacity in hydropower reservoirs in the highlands and large irrigation withdrawals in the lowlands. The qualitative analysis consists of mapping the interrelationships – synergies, trade-offs and feedback loops – between sectoral water users, water resources, and governance systems through the Causal Loop Diagram and the Network of Action Situation methods. On a quantitative level, a water resources management model of the Orco catchment is developed and used to simulate water allocation strategies across sectors for the period 2011 – 2022. Results show that irrigation needs were only fully met in a few years and that the upstream-downstream positioning influenced the frequency and intensity of water shortages, as well as the impact of prioritising environmental flows on water withdrawals by different irrigation districts. Water stored in hydropower reservoirs could potentially help mitigate irrigation water deficits in late July and August, resulting however in a reduction of hydropower production in winter months. Furthermore, addressing water scarcity would require overcoming socio-economic barriers associated with current agricultural practices, a radical transformation of the irrigation distribution system, the adaptation of withdrawal permits to a changing climate and further cooperation between upstream and downstream water users. Nevertheless, signs of cooperation were already found in the Orco watershed, indicating the willingness of the local community to address the issue of water scarcity collectively.