This thesis presents a comparative analysis of water allocation systems and their legal and institutional impacts on Bulk Water Removal (BWR), based on Canadian (Manitoba) and Brazilian (Ceara) systems. First, it studies the BWR concept, opportunities and problems, federal-provincial jurisdiction, international issues and management duties. Then, it analyses the water allocation issues that contribute to water shortage and needs for BWR. This thesis argues that legal frameworks as well as policies can contribute to scarcity and the need for water transfer. Current water allocation regimes are not effective in dealing with water scarcity and, in fact, tend to exacerbate the problems experienced in the two regions studied. Thus, either a simple BWR moratorium or a non-assessed and non-monitored BW is an unsustainable solution to water scarcity issues. This thesis concludes its analysis by offering suggestions for future water allocation systems, which include a legally well-defined water rights concept, participative and decentralised water management and an integrated legal strategy to establish adaptable allocation mechanisms. This will answer current and potential water demands and serve to avoid future water shortages, conflicts and needs for BWR.