Water covers 71% of the Earth's surface. It is vital for all known forms of life. On Earth, 96.5% of the planet's crust water is found in seas and oceans, 1.7% in groundwater, 1.7% in glaciers and the ice caps of Antarctica and Greenland, a small fraction in other large water bodies, and 0.001% in the air as vapor, clouds, and precipitation.
Safe drinking water is essential to humans and other lifeforms even though it provides no calories or organic nutrients. Access to safe drinking water has improved over the last decades in almost every part of the world, but approximately one billion people still lack access to safe water and over 2.5 billion lack access to adequate sanitation. There is a clear correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in some developing regions of the world, water demand will exceed supply by 50%. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70% of the freshwater used by humans goes to agriculture. (source: https://en.wikipedia.org/wiki/Water)
The Environment Statistics Database contains selected water and waste statistics by country. This data set includes metrics for precipitation, fresh water flow, renewable freshwater, actual evapotranspiration and freshwater internal flow.
Statistics on water and waste are based on official statistics supplied by national statistical offices and/or ministries of environment (or equivalent institutions) in countries in response to the biennial UNSD/UNEP Questionnaire on Environment Statistics. They were complemented by data on EU and OECD member and partner countries from OECD and Eurostat. Environment statistics is still in an early stage of development in many countries, and data are often sparse. The statistics selected here are those of relatively good quality and geographic coverage. The online database currently covers the years 1990, 1995 to 2009.