To face water challenges in line with the Sustainable Development Goals, Paris Agreement and United nation climate conference, ICT technology is a key enabler to improve water resources management in man-made or natural environment, especially regarding monitoring and reporting quality, quantity, reuse of water, extreme events (floods and water scarcity), smart Decision Support System (DSS), leakages and awareness of the true value of water by all stakeholders. The water industry of the future will be smart and resource-efficient. Networked, intelligent systems will help make better use of energy, avoid unnecessary water losses and minimize the consumption of resources. Despite a promising technological scenario, currently, the water domain is characterized by a low level of maturity concerning the standardization of ICT solutions, their business processes and the related implementation in the legislative framework. This is due to the fragmentation of the sector, no holistic vision being set out and a lack of integration and standardization of the technology. The development of system standards is essential for smart water solutions that should ensure interoperability of solutions, i.e. adaptability of solutions to new user requirements and technological change as well as avoidance of entry barriers or vendor lock-in through promoting common meta-data structures and interoperable (open) interfaces instead of proprietary ones. Two roadmaps based on the contribution of the ICT4Water cluster1 that record gaps, social, organizational and technological challenges have been published (roadmaps published in 20152 and 20163). A subsequent milestone is the publication of this report suggesting an Action Plan 2018-2030 that focuses on implementation of actions related to interoperability and standardization, data sharing, smart water, cyber-security, actors' awareness, policy and business models. This initiative contributes to the Connected Digital Single Market and the Resilient Energy Union objectives by promoting energy efficient smart ICT technologies in the water sector. The innovation potential includes the shift from pilot scale initiatives to a vision beyond uncoordinated and isolated initiatives, wide market uptake, aiming to end up with the creation of a Digital Single Market for efficient and sustainable water services.