The involvement of multiple decision makers in water resources management can be very complex, involving the possibilities of conflicts amongst the stakeholders and the influence of powerful members over the preference of others. The inherent characteristic of decisions also increases this complexity due to many alternatives being involved and there being multiple criteria. Some of these criteria conflict with each other and the consequences of which will have great impact on those involved and on third parties. Therefore, a group decision support system model based on multicriteria analysis can be a powerful tool to support this kind of management. This study presents a tool to support the committee responsible for the management of the watersheds in Brazil in order to promote decentralization and the participation of all involved in the water resources management. The tool provides a ranking of alternatives for the environmental recuperation of the watershed through the use of the multicriteria method PROMETHEE II. For each decision maker, the alternatives were ranked and then the individual rankings were combined into a global ranking which contained the preferences of the whole group.
Multicriteria analysis Group decision PROMETHEE Water resources management