The problems of water use and water availability have a long history. For thousands of years, the people had used water in agriculture and for satisfying their own needs, while in the recent centuries the water supply of industry has been added here. However, beginning from the mid-twentieth century, the use, distribution, and reproduction of water resources have acquired special relevance. The quickly growing world population, industry development, and expanding agricultural lands have led to the water deficit which is increasing with every passing year. The water demand runs ahead of the population growth rate. Many international organizations and individual states exerted enormous efforts to find the way to cope with this issue but so far without success. In the recent decades this has led to the growth of interstate contradictions of interests which gave rise to international instability and even to conflicts. This issue is so acute that the conflicting parties fail to find compromise. It means that in the nearest decades, we may witness the revival of “water wars” which will affect enormously the political map of the world. © Springer Nature Switzerland AG 2020.