Existing water institutional structures are either failing to address water challenges or are poorly equipped to cope with increasing pressure on water resources and the governance systems handling these resources. Different institutions are competing for leadership on water governance issues, which may already lead to duplications, contradictions and inefficiencies. In this chapter, I undertake an inquiry into the relation between global water institutional structures, with particular emphasis on the UN, and possible outcomes in terms of addressing impending water crises. I first discuss the key problems for global-level water governance and outline the trends in that governance, with a particular focus on the role that UN organs can play. I then present stories of what the world of water and water governance are likely to look like in 40 years and through this seek to identify the common challenges to water governance that could be suitably addressed at the global level and the possible institutional and legal responses to these challenges. I then analyse and compare these possible responses with a particular view to their compatibility with achieving one or another of the possible futures. This chapter is not an attempt to argue for any particular strategy or outcome. It merely attempts to highlight the connections between the two and to suggest therefore that water managers and water policy experts consider both in deciding on strategies for the future, selecting the strategy that seems to offer the best opportunity for achieving the most desirable future.