Background The Esino river catchment is located in the central area of the Italian Marche Region. Its environmental condition is poor as a result of intensive agricultural and industrial activities, and uncontrolled pollution loads from untreated discharge and combined sewer overflows. It is also located in a region that has been declared a nationally-relevant Area at High Risk of Environmental Crisis, due to its high density settlements, highly hazardous industrial plants and internationally significant infrastructure. Several wells used for public water supply and for agricultural and industrial activities are located in the lower Esino river valley. However, these wells face high risk of contamination. The inadequate management of urban and agricultural pollution, and the unsustainable and uncoordinated use of water resources, are leading to adverse environmental consequences, including seawater intrusion in the lower Esino river aquifer. Climate change promises to exacerbate these threats by reducing natural aquifer recharge and rising sea levels. Objectives The overall objective of the SALT project was to contribute to the efficient use of groundwater resources in the lower Esino river valley and thus their protection from saltwater intrusion. The project aimed: To analyse the trends of saltwater intrusion into the Esino River and related aquifers and their effects; To simulate future scenarios of salt intrusion in the project area; To define remediation actions to prevent salt intrusion increase and develop a tool to evaluate the impact of different management options on the quality and quantity of the aquifer; and To disseminate information on the proposed solutions that address saltwater intrusion in the Marche Region and elsewhere in Italy and Europe.Results The SALT project beneficiary Multiservizi modelled the entire hydrologic system of the Esino basin and consequently assessed the possible damage in the territory due to salt intrusion and modifications of the stratum level. These are considered the main possible effects due to climate change in the project area, with all the impacts on the territory depending on their degree of severity. The project’s assessments were looked at with respect to the Intergovernmental Panel on Climate Change’s Special Report on Emissions Scenarios (IPCC-SRES); particularly the ones that were considered most probable in the period 2070-2100. The project was expected to define remediation actions to prevent salt intrusion in the project area, and to develop a Regional Risk Assessment procedure to support aquifer management. However, in light of the project’s key finding that the Esino river basin will not be significantly affected by salt intrusion, it was considered unnecessary to identify remediation actions. As for the Regional Risk Assessment, the beneficiary developed a planned procedure by defining maps of ‘exposures’, ‘risks’ and ‘damages’, thus identifying impacts, targets and areas potentially subject to climate change. The developed tool supports decision-makers in charge of managing water resources in river basins, by enabling them to assess possible actions to prevent risk and/or damage. Advanced tools were used to implement the project actions: aquifer and climate change mathematical models and specific data acquisition systems. This delivered a practical methodology for evaluating salt-water intrusion on costal aquifers in present and future scenarios determined by climate change. In addition, the project tool integrated a surface water model (quality and quantity) with underground water models, enabling a full analysis of the water cycle. The developed procedure seems reliable enough to foresee the possible impacts of climate change over the next 100 years. The tools developed in the framework of the project can be easily updated or upgraded in the future, and the project has a good demonstration value as the methodology can easily be replicated in other river basin areas. The SALT project outcomes provide indirect environmental benefits, through the tool that can be used for implementing positive actions for the preservation of water resources. The project therefore supports the EU policy objective of encouraging resource efficiency through more sustainable water consumption patterns, as set out in the Sixth Environment Action Programme and the Water Framework Directive (WFD - Directive 2000/60/EC). In cases where the project tool will be used by policy-makers and water resource managers, the aim is to preserve freshwater sources. This should prevent possible negative effects on the whole socio-economic system of the area, as water is necessary for numerous economic activities and for ecosystem and human well-being, though such benefits can only realistically be assessed in the long term. Further information on the project can be found in the project's layman report(see "Read more" section).