This paper analyses freshwater as a strategic resource of the 21st century. The aim of the research is to review the world's water resources at all levels, explain the situation in Croatia, and develop possible scenarios for the period from 2020 to 2035. Therefore, in addition to the Introduction and Conclusion, the second chapter sets out the theoretical and conceptual framework of the research and defines the key factors that lead to the water crisis. These are the growth of the world's population and its drinking water consumption, and the dominance of the agricultural sector over other sectors in order to meet world food demand. The third chapter observes the situation of the Republic of Croatia and analyzes the problems its water management system is facing. The fourth chapter provides a projection of world water supplies at the global, continental, regional and national level, and defines the regions that are most vulnerable to the issue of water scarcity. Finally, the fifth chapter deals with the development of scenarios for the period from 2020 to 2035 in order to show the importance of policies, reforms and investments on the issue of water scarcity in the world.