The MULINO project was developed within the European water policy context, as defined by the Water Framework Directive (2000/60/EC), with three main objectives: 1. To design and implement an operational decision support system for the management of water resources that is based on hydrologic modelling, multi-disciplinary indicators and a multicriteria evaluation procedure. 2. To test the system in representative case studies in co-operation with local water management administrations. 3. To demonstrate the potential of the tool in supporting the sustainable management of water resources in Europe. The final result is a tool, the MULINO DSS software “mDSS”, that has been developed as a stand-alone software, and an overall methodology within which the tool can be applied for an integrated approach to decision problems related to water management. The software incorporates integrated analysis modelling (IAM), multi-criteria analysis (MCA) and the European Environment Agency’s DPSIR framework, adopting state-of-the-art data formats to guarantee interoperability. The system does not require additional software, which should improve the potential for its utilisation by water management administrations. Optional links with GIS software, hydrological models and/or meta-models are provided, and in the last version of the software a full coupling procedure links mDSS3 with the CRASH hydrologic model. The software can be coupled also with any hydrological model which respects a standard input/output procedure. The MULINO website and CDRom containing the software and all of its support materials are available for free distribution.