PREMISE •At present, drinkable water is only 1% of earth’s water. Rest of the water is either saline or polluted. Many regions on the planet has very little rain or no water supply. Many people suffer from draught every now and then. Increasing pollution and global warming is turning earth from green plant to dry planet. We are dependent on water cycle on earth for constant regulation of water. •The water cycle describes the continuous movement of water on, above and below the surface of earth. In summer, surface water gets evaporated due to high temperature. These vapors are free from any chemical contaminants, because chemical elements do not evaporate at the atmospheric temperature. These vapors rise above the ground level and condense into form of clouds. These clouds then, pour water on earth in form of rain. Thus completing the water cycle. By transferring water from one reservoir to another, the water cycle puriﬁes water, replenishes the land with freshwater, and transports minerals to different parts of the globe. •Since, rainwater is free from any chemical pollutant, it can be used as drinking water and other household activities. But, as soon as rainwater falls on the ground, it starts seeping into ground. The collection of pure rainwater, before it reaches the aquifer is called rainwater harvesting.