AquaNES is an Innovation Action funded by the European Union's Horizon 2020 programme.The AquaNES project will catalyse innovations in water and wastewater treatment processes and management through improved combinations of natural and engineered components. Among the demonstrated solutions are natural treatment processes such as bank filtration (BF), managed aquifer recharge (MAR) and constructed wetlands (CW) plus engineered pre- and post-treatment options.The project focuses on 13 demonstration sites in Europe, India and Israel covering a representative range of regional, climatic, and hydrogeological conditions in which different combined natural-engineered treatment systems (cNES) will be demonstrated through active collaboration of knowledge and technology providers, water utilities and end-users.Our specific objectives are• to demonstrate the benefits of post-treatment options such as membranes, activated carbon and ozonation after bank filtration for the production of safe drinking water• to validate the treatment and storage capacity of soil-aquifer systems in combination with oxidative pre-treatments• to demonstrate the combination of constructed wetlands with different technical post- or pre-treatment options (ozone or bioreactor systems) as a wastewater treatment option• to evidence reductions in operating costs and energy consumption• to test a robust risk assessment framework for cNES• to deliver design guidance for cNES informed by industrial or near-industrial scale expe-riences• to identify and profile new market opportunities in Europe and overseas for cNESThe AquaNES project will demonstrate combined natural-engineered treatment systems as sustainable adaptations to issues such as water scarcity, excess water in cities and micro-pollutants in the water cycle.