Every year edge.org poses a ‘big question’ to the world’s intellectual community. Taking inspiration from them, at a much more modest scale, we asked a number of IWRA members who are international scholars and practitioners concerned with water quality to give us their reflections on the question, ‘What is a wicked problem facing integrated water quality management over the next two decades?’ In the end we received six responses spanning a gamut of concerns, from problems of allocation, management and monitoring, to ensuring sustainable development in global agriculture and in rapidly urbanizing China, to the troubling presence of pharmaceutical wastes. It is increasingly obvious that water supply and water quality are not separate domains, and cannot be managed in isolation if there is to be any hope of addressing these wicked problems.