Water is a critical resource for the European society. Beside its main life function, freshwater also provides many other functions essential to our economy such as transport, energy provision, heat exchange, cleaning, washing, and constitutes a necessary raw material for many industries. Water availability in sufficient quantities and adequate quality is an issue of highest priority and represents a pan-European and global societal challenge. Water challenges cannot be successfully tackled through the isolated effort of individual national research and innovation programmes. A significant share (more than 70%) of public spending in water research and technology development is programmed, executed and evaluated at national level.Joint Programming Initiatives (JPI) aim at a coordinated and strategic approach to public national and regional research and innovation funding in Europe. Ten critical societal challenges have been identified in Europe and are being addressed through Joint Programming. “Water Challenges for a Changing World” (the Water JPI) is one of them. The Water JPI aims at achieving sustainable water systems for a sustainable economy in Europe and beyond.WatEUr will prepare and support the successful development and implementation of the Water JPI. WatEUr will permeate the structures of the Water JPI to impulse progress towards JPI objectives. Now that Water JPI Vision and Management Structure have been developed, actions are needed to sustain the current structures and to fasten progress in joint activities between national/regional programmes in Europe that will make the Water JPI instrumental to the Research, Development and Innovation community, and effective in tackling European water challenges. Examples of such joint activities include the recurrent mapping of national and regional RDI funding, institutions, programmes and projects, the iterative production of Strategic Research and Innovation Agendas, the undertaking of joint activities including the coordination of joint RDI agendas, joint call(s) on a variable geometry, coordination with water RDI activities within and outside Europe and joint dissemination.WatEUr and the Water JPI will benefit researchers, policy-makers, water authorities, utility operators, industry, farmers, and citizens by developing new solutions to water challenges. Solutions will include safe supply of clean drinking water, improved protection against new emerging water pollutants or pathogens and water hazards like floods and droughts, and a progressive shift towards a more water-efficient economy in Europe.Water knows neither political nor administrative borders. As a matter of fact, most of the European territory falls within transboundary watersheds. WatEUr will assist the Water JPI in addressing fragmentation, preventing duplication of efforts and guaranteeing sufficient critical mass.