Modern condition and role of rational water use in megapolis

Rational water use is the process of effective use of water resources, which guarantees the preservation and protection of water bodies from negative and excessive anthropogenic impact, while ensuring the population and branches of the national economy with water resources. The article is devoted to the analysis of the modern state of a metropolis in the conditions of a metropolis on the example of different countries of the world. The problem of water resources of Russia and the World is considered in general. It is necessary to show the role of rational water use in a megacity.