Groundwater resources are under strain in many Archimed areas because of conflicting water uses and heavy demand. Conflicts between various land-use activities arise, trying to resolve water supply and environmental protection. In order to resolve such conflicts in a reliable manner, optimizing the use of the resources and the potential of a certain region, spatial development strategies are indispensable. To develop optimal spatial development strategies, authorities need scientifically reliable information. For groundwater resources, this information is provided by vulnerability maps, which are used as a tool to determine areas where aquifers are in high risk of pollution. The project WATER-MAP will produce GIS-based vulnerability maps to support the spatial development planning process. To facilitate and optimize the decision-making process relating to the problems of land use/water management/environmental protection, WATER-MAP will also develop and implement a decision support system with information on land uses, populations, etc. The spatial integration of the vulnerability maps in the decision support system will enable the regional authorities to design optimal spatial development policies. Partners from the four EU Archimed countries are participating in WATER-MAP, including Regional Authorities, water management authorities, and regional development agencies. The project territories will organize Regional Partnerships and set thematic focuses covering the respective key problem areas, mainly from the viewpoint of land use (e.g. agriculture, industrial development, housing development, etc). Together, these focuses will meet the entire spectrum of use-specific problems and result in the production of a Best Practice Guide that will integrate all information in practical guidelines for regional planners and policy makers. The production of the guide will be facilitated by the organization of 2 exchanges of staff and 2 joint workshops, further strengthening the transnational character of the project. The main beneficiaries of WATER-MAP are the policy makers that are involved in spatial development. This group encompasses policy makers in all sectors and geographical levels. Other beneficiaries include the citizens of the project territories, the economic actors of the project territories (farmers, industry, services), and the tourists that visit the project territories.