Water management is a fertile terrain for research, and can be investigated using several methodological instruments and approaches. Multipurpose water resources, which allow for the contemporary presence of in-stream (fishing, swimming, etc.) and off-stream uses (agriculture, household, etc.), are particularly difficult to management due to increasing water demand and the conflict between consumptive and not consumptive uses. New scenarios in agricultural policy (Reform of the European Common Agricultural Policy) and new requests from local stakeholders (recreational activities, rising household water demand, etc.) involve use of decision support methods to find a balance between multiple potential uses. This study describes the application of multicriteria decision aid for choosing the best project for water management and local development among a set of alternatives, using the regime method. The regime method can integrate quantitative data with quality judgement and preference index. The study aims to verify if the regime approach is understandable for the decision maker and if it is suitable for use in ambiguous situations where no quantitative information is available. It is not always possible to get the 'best alternative' in multicriteria evaluation: in this study we found two top-rank alternatives, with minor differences, to submit to the decision maker.