The earth has a limited amount of water. However the water comes around in a cycle that if left alone it will never run out. This process though is called the water cycle, It starts off with Evaporation, when the heat of the sun turns the water from rivers, lakes, or oceans and turns it into vapor and goes into the air. Condensation then starts, when water vapors becomes very cold and changes back into liquid forming clouds. Precipitation occurs when enough liquid has been collected in the clouds and the air cannot hold it anymore, then it starts to rain. When it rains it falls everywhere, but when it hits concrete the water is unable to be absorbed into the ground. Instead the water then travels down storm drains into the oceans where it brings no use to society.