Water is the source of life and indispensable for life. Its presence defines our everyday lives. As drinking water it is an essential part of human nutrition. It is also used for personal hygiene: washing and keeping our environment clean. It plays an important role in agriculture as irrigation and drinking water. It is a renewable energy source of great importance with the least adverse impact and it plays crucial role in industry, transport and freight transportation too. Through the holidays, water sports and spa water it is an important factor in maintaining health.

We take its existence for granted even though we hear more and more of imminent threats on Earth's water supply. The tragic shortage of drinking water, drying up lakes, more frequent catastrophic floods, barren, parched land, the disappearance of ecologically important habitats a are consequences of global warming: harmful activities of humanity. In the future, water, clean water may well become important strategy product, or even the most important natural treasure . . After all, even though our planet is called " the blue planet ", only 2.5-3 % of the water resources is fresh water, and only a small portion of it ( 0.03 % of the total water resources on Earth) can be used for mankind, the rest is frozen or located below the surface.