CASTWATER is the first Mediterranean project to support sustainable tourism policies & practicies on water efficiency in coastal areas. The transnational challenge is to reduce the impact of tourism activities on environmental heritage and to improve management of water resources. CASTWATER follows a studying, testing and transferring approach of transnational cooperation, involving public authorities, tourism enterprises, relevant agencies and stakeholders. Every 6 months, reports are done on the progress and quality, yearly reports are done on impact and communication evaluation. Since the project is in its early phases, it is too soon to guess about results and the impact, yet it is clear that there is very little awarness on the importance of water conservation. CASTWATER contributes to International Year of Tourism for Development 2017 by proposing technological solutions to water consumption reduction, sharing knowledge about resource efficiency, raising awarness among SMEs, providing online toolkits, managing pollution and etc.