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...