Water: quantitative data

Without water, life would not have appeared on Earth some 3.8 billion years ago. Water, an element essential to life and a "national heritage" (article 1 ^er of the French Water Act of January 3, 1992), has obviously been a constant preoccupation in all times and places. The total quantity of water on Earth has remained constant for more than 4 billion years: under the effect of the sun, water evaporates, condenses in the atmosphere to form clouds and then falls as precipitation, then runs off, infiltrates, before re-emerging and evaporating again: this is the water cycle.

There are many uses for water, and we felt it essential to provide readers with a certain number of data and statistics concerning these uses.

The data presented in this article come from a variety of sources, including institutional bodies, private operators, etc. Great efforts have been made by various players to produce reliable data, while often recognizing the lack of basic figures. What's more, final validation requires a great deal of time to cross-check all available information. For this reason, it is not yet possible to have all the data validated for the current period, at the end of 2022.