Canada is a party to one of the world’s better-known institutions for transboundary water management, the Boundary Waters Treaty of 1909 and the organisation it created, the International Joint Commission (e.g. Fischhendler and Feitelson 2005). Less well known internationally are institutions for transboundary water management within Canada. Internal transboundary experiences are pertinent in the context of this book because, we argue, the challenges of governing water across jurisdictional boundaries within countries organised as federations can be as profound as those facing sovereign countries. For instance, conflicts such as the ‘Tri-State Water Wars’ among Georgia, Florida and Alabama (Jordan and Wolf 2006) point to the need for effective transboundary water management in the United States. Australian experiences with transboundary water governance in the Murray–Darling Basin also offer numerous insights relevant for federal states (e.g. Bhat 2009; see also Ross and Connell, Chapter 13, this volume). Like Australia and the United States, Canada is a federation where responsibility for water is divided among jurisdictions at multiple levels. Under Canada’s constitution, the federal government and the ten provincial governments share responsibility for water. The division of responsibility in Canada is complex because water is not mentioned specifically in the Canadian constitution