Background The main problems of the Strymonas river basin in Central Macedonia, Greece, relate to water management. The problems are threefold: There is loss of water due to an incomplete or damaged irrigation distribution network; there are undesirable alterations in the hydro-period of the ecosystem of the artificial reservoir of Lake Kerkini (a Ramsar site) and finally; there is saltwater intrusion in the river during irrigation seasons because of diminished discharge. These problems are due to the current water management and farming practices which have serious impacts on the status of the surface waters, groundwater and coastal ecosystems. Other problems of the Strymonas river basin relate to diffuse sources of pollution, specifically nutrients (NO3 – N and PO4 – P) in the surface waters resulting from intensive agricultural practices. The reuse of drainage water for irrigation in turn leads to eutrophication of the Strymonikos Gulf and salinization of the downstream agricultural soils. Objectives The LIFE Environment project had the overall objective of promoting the sustainable management of surface waters and groundwater in the Strymonas river basin, thereby assisting in the implementation of the Water Framework Directive. Specific objectives included: Use of state-of-the-art modelling tools for assessing the impacts of the agricultural sector on the status of the surface and groundwater in the basin Use of optimisation methods to elaborate and suggest solutions for the sustainable management, protection and restoration of all water bodies in the basin Dissemination of both the methodological framework and the results of the project to local and national authorities, as well as to the scientific community. Results The project was satisfactorily completed. The beneficiary succeeded in establishing a hydrology-hydraulic modelling tool (MIKE SHE / MIKE 11) for the Strymonas basin. This tool was used to calculate the quantity of water in the basin, the spatial and temporal needs as well as losses of water for irrigation. Satellite-image-analysis methods were applied for crop identification. Remote sensing fed MIKE SHE / MIKE 11 with data on the spatial distribution of the crops and in turn, the model calculated the real irrigation needs in the Strymonas basin and the applied quantities of fertilisers and pesticides. To provide the necessary ‘on the ground’ data for the simulation model, a water quality (16 stations) and quantity (12 stations) monitoring network was established. Real-time measurements were made possible by the invention of an automatic water flow measuring device, which the project designed, developed and installed near the mouth of the Strymonas river. For the assessment of alternative solutions for the sustainable management of water resources and agro-ecosystems, a farm management survey was conducted over a random sample of 250 farms in the Strymonas basin. Data from this survey were analysed in order to assess farm management practices in the basin and to propose alternative plans for the re-arrangement of local agriculture. From this procedure, 25 optimum alternative solutions / scenarios were produced and two of them were considered as the most appropriate, following consultations with local stakeholders. Data from the two re-arrangement plans were fed into the simulation model that in turn calculated, inter alia, the quantity of water required for irrigation. In both plans, water volume was lower by around 20% than the volume currently required. Many dissemination activities were organised throughout the project's duration, targeting mainly the local and regional stakeholders. Disclaimer : This « results » section should be considered as a draft until the Commission has completed its evaluation .