Water is an increasingly threatened resource, particularly the quality of coastal and inland waters due to population growth, urbanization, and climate change. Further, the interfacial nature of the coastal zone, bridging aquatic, terrestrial, atmospheric, and anthropogenic domains, means they are significantly impacted by dynamic, complex processes. Timely, accurate, and consistent scientific-based assessments, monitoring and forecasting of water quality are crucial across global, regional, and local scales. This session solicits contributions addressing the end-to-end value chain for coastal and inland water quality. This includes new and improved physical, biogeochemical, and ecological observations and data products (remote and in situ), data assimilation and forecasts, and synergistic generation of fit for purpose water quality products and indicators to provide integrated information for water quality managers and other stakeholders. Developmental and operational activities that couple products and indicators (from observations, models etc.) across the land-water interface are solicited, likewise information delivery systems and decision-making tools that enhance user knowledge. This session advances the goals of the AquaWatch Initiative being developed under the auspices of the Group for Earth Observations, particularly development of water quality monitoring and forecasting service(s) in developed and developing nations, supporting the U.N. Sustainable Development Goals, especially SDG-6: Clean Water and SDG-14: Life Below Water. Studies focusing on data products, applications, and operational services should submit to this session; abstracts focusing more on the basic understanding of biogeochemical processes associated with water quality should instead submit to the “Water quality monitoring and forecasting in coastal waters: Biogeochemistry of urban systems” session.