Water from the sea is warmed by the sun and turned into water vapour. The water vapour turns into clouds, from where it can fall as rain. Rainwater runs down from the mountain slopes into rivers and man-made dams. From here underground pipes take the water to a treatment plant where it is made clean for us to drink. From there it runs through pipes to our homes.
The waste water from our homes and factories goes to the sewage treatment plant, where it is cleaned. It then goes back into the sea and rivers. In this way our water is recycled again and again.