Decision Support Systems (DSS) are important tools for both producing and processing information and to make it available in such a format that help decision makers and users to make the best decisions. To cope with the variety of DSS and models, it was developed a concept of a GIS framework - HIDROGEST - to integrate such tools, thus creating a unified database, extending it with GIS functionalities, and reusing the output data of given models as input data for other models. Thus, HIDROGEST provides an integrated approach to the decision-making process aiming improved water use and participatory management in irrigation. One of the models included in HIDROGEST is AKLA, a model for performance analysis of pressurized networks operating on-demand that simulates its hydraulic behavior for several flow regimes and computes appropriate performance indicators. When integrated in a visual framework, the model allows the manager and technical staff of water users associations (WUA) to analyse alternative demand scenarios relative to cropping patterns and water availability, as well as changes in the infrastructure network, which results may be analysed with farmers in participative sessions prior to or during the irrigation season to assess the most probable constraints in water delivery. Results may also be used to define outlet discharges and pressure available for farm irrigation systems design, thus to establish broad scenarios of water use inside an irrigation project aimed at improving water use in irrigation.