A web tool to support River Basin Management planning towards achieving European environmental targets

Aquatic ecosystems are exposed to multiple pressures due to increasing water demands and pollution. The European Union legislation demands achieving environmental targets (good ecological and chemical status) in all fresh and marine water bodies by deploying adequate River Basin Management plans that tackle the main pressures acting on aquatic habitats. Decision-makers are confronted with conflicting trade-offs between legislative environmental targets and economic activities, while maintaining a basis of transparency and accountability. Strategies for achieving freshwater environmental targets, like reduction of nutrient pollution, may differ in terms of type, location, costs and benefits of planned actions. ESPRES is a web-based Decision Support Tool (DST) designed to explore efficient management strategies and highlight trade-offs between environmental targets and socio-economic difficulties. The DST, which is currently available for four European River Basins, provides several options to set environmental targets in fresh water bodies. Specifically, environmental targets refer to either water quantity (reduction of water abstractions) or quality (currently limited to nitrogen pollution). Identification of efficient strategies depends on several decision-maker choices and perceptions. For example, defining the specific environmental outcome, e.g. reducing mean or maximum nitrogen concentrations, or differences in tackling sectoral issues, will stir efficient strategies towards specific sets of actions. ESPRES makes these choices transparent through several functionalities. We present comparative examples of ESPRES analysis using alternative nitrogen concentration outcome objectives for the Ebro River Basin case study, meanwhile providing an overview of the DST functionalities. Ideally, ESPRES is meant for decision-makers to explore and compare the range of options that could achieve environmental outcomes efficiently. The tool can also be used for negotiation among stakeholder groups, making rationales behind different positions more transparent, but also for educational purposes, to showcase the steps in decision-making and their consequences on environmental planning. We envisage to expand ESPRES to all European Basins. Further, strategies set for compliance with freshwater environmental requirements may not automatically fulfil targets set for marine water bodies at the river outlet. Foreseen developments of the tool will include new functionalities for considering impacts to marine water bodies and therefore expand impact analysis to the full aquatic system continuum.