Answer:
Rainwater harvesting is an expertise for collection and efficient storage of rainwater from different basement areas like rooftops of residential buildings, ground surface, rock catchments, etc. These techniques are very vast. They can be very artless techniques such as collection and storage using readily available, cheap utensils. They also can be some very intricate techniques such as building check dams. These methods are mostly used for water conservation. Usually, there are two basic ways of rainwater harvesting like surface runoff harvesting and rooftop rainwater harvesting. In the first method, rainwater flowing along the surface is collected in an underground tank. In the second method, rainwater is collected from roof catchment and stored in a tank. The harvested rainwater is the purest form of water source. So, it can be consumed directly. Rainwater collected from ground catchments may be poor in quality with respect to the bacteriological quality, whereas if rainwater is collected from well-maintained rooftop catchment systems and storage tanks, then that water is suitable for drinking. If water is collected from a dirty surface, then the collected water can be made utilizable by using a proper filtering system. Thereafter, it can be used for some the following purposes like drinking, culinary, bathing, laundry, toiletry purpose, watering gardens, compost making, birdbaths, recharging ponds and pools, washing vehicles, fire extinguishing, etc.