A participatory and integrated procedure for the planning of water resources is presented and illustrated through its application to a real-world case study: the planning of a trans-boundary, multi-purpose, regulated lake. Methods and concepts from Hydrology, System Analysis, Optimal Control, Decision and Negotiation Theory are presented and framed in a comprehensive and coherent procedure for the efficient development of the decision-making process. Relevant theoretical and mathematical aspects are briefly presented for the non-expert reader, as well as all those practical details that are often omitted in texts, but that constitute the very essence of a project and make the difference between a successful project and a failure. The book provides practicing professionals, decision-makers and scientists with a complete, immediate example of application of the Integrated Water Resource Management paradigm.